From cb2da5430ade9fcb33d546bdc2ac95ec7402d3b1 Mon Sep 17 00:00:00 2001 From: "W. Trevor King" Date: Mon, 28 Dec 2015 10:06:40 -0800 Subject: [PATCH] config: Single, unified config file Reverting 7232e4b1 (specs: introduce the concept of a runtime.json, 2015-07-30, #88) after discussion on the mailing list [1]. The main reason is that it's hard to draw a clear line around "inherently runtime-specific" or "non-portable", so we shouldn't try to do that in the spec. Folks who want to flag settings as non-portable for their own system are welcome to do so (e.g. "we will clobber 'hooks' in bundles we run") are welcome to do so, but we don't have to have to split the config into multiple files to do that. There have been a number of additional changes since #88, so this isn't a pure Git reversion. Besides copy-pasting and the associated link-target updates, I've: * Restored path -> destination, now that the mount type contains both source and target paths again. I'd prefer 'target' to 'destination' to match mount(2), but the pre-7232e4b1 phrasing was 'destination' (possibly due to Windows using 'target' for the source?). * Restored the Windows mount example to its pre-7232e4b1 content. * Removed required mounts from the config example (requirements landed in 3848a238, config-linux: specify the default devices/filesystems available, 2015-09-09, #164), because specifying those mounts in the config is now redundant. * Used headers (vs. bold paragraphs) to set off mount examples so we get link anchors in the rendered Markdown. * Replaced references to runtime.json with references to config.json. [1]: https://groups.google.com/a/opencontainers.org/forum/#!topic/dev/0QbyJDM9fWY Subject: Single, unified config file (i.e. rolling back specs#88) Date: Wed, 4 Nov 2015 09:53:20 -0800 Message-ID: <20151104175320.GC24652@odin.tremily.us> Signed-off-by: W. Trevor King --- Makefile | 2 - README.md | 10 +- ROADMAP.md | 7 - bundle.md | 16 +- config-linux.md | 550 +++++++++++++++++++++++++++++++++++++++ config.go | 39 ++- config.md | 116 +++++++-- config_linux.go | 294 +++++++++++++++++++++ glossary.md | 2 +- runtime-config-linux.md | 553 ---------------------------------------- runtime-config.md | 122 --------- runtime.md | 6 +- runtime_config.go | 42 --- runtime_config_linux.go | 306 ---------------------- style.md | 2 +- 15 files changed, 989 insertions(+), 1078 deletions(-) delete mode 100644 runtime-config-linux.md delete mode 100644 runtime-config.md delete mode 100644 runtime_config.go delete mode 100644 runtime_config_linux.go diff --git a/Makefile b/Makefile index bb69ace03..224f085c7 100644 --- a/Makefile +++ b/Makefile @@ -12,8 +12,6 @@ DOC_FILES := \ runtime-linux.md \ config.md \ config-linux.md \ - runtime-config.md \ - runtime-config-linux.md \ glossary.md EPOCH_TEST_COMMIT := 041eb73d2e0391463894c04c8ac938036143eba3 diff --git a/README.md b/README.md index f0d90776b..bfff859e5 100644 --- a/README.md +++ b/README.md @@ -9,10 +9,8 @@ Table of Contents - [Specification Style](style.md) - [Filesystem Bundle](bundle.md) - Configuration - - [Container Configuration](config.md) - - [Container Configuration (Linux-specific)](config-linux.md) - - [Runtime Configuration](runtime-config.md) - - [Runtime Configuration (Linux-specific)](runtime-config-linux.md) + - [General](config.md) + - [Linux-specific](config-linux.md) - [Runtime and Lifecycle](runtime.md) - [Linux Specific Runtime](runtime-linux.md) - [Implementations](implementations.md) @@ -27,12 +25,12 @@ To provide context for users the following section gives example use cases for e #### Application Bundle Builders Application bundle builders can create a [bundle](bundle.md) directory that includes all of the files required for launching an application as a container. -The bundle contains OCI [configuration files](config.md) where the builder can specify host-independent details such as [which executable to launch](config.md#process-configuration) and host-specific settings such as [mount](runtime-config.md#mount-configuration) locations, [hook](runtime-config.md#hooks) paths, Linux [namespaces](runtime-config-linux.md#namespaces) and [cgroups](runtime-config-linux.md#control-groups). +The bundle contains an OCI [configuration file](config.md) where the builder can specify host-independent details such as [which executable to launch](config.md#process-configuration) and host-specific settings such as [mount](config.md#mounts) locations, [hook](config.md#hooks) paths, Linux [namespaces](config-linux.md#namespaces) and [cgroups](config-linux.md#control-groups). Because the configuration includes host-specific settings, application bundle directories copied between two hosts may require configuration adjustments. #### Hook Developers -[Hook](runtime-config.md#hooks) developers can extend the functionality of an OCI-compliant runtime by hooking into a container's lifecycle with an external application. +[Hook](config.md#hooks) developers can extend the functionality of an OCI-compliant runtime by hooking into a container's lifecycle with an external application. Example use cases include sophisticated network configuration, volume garbage collection, etc. #### Runtime Developers diff --git a/ROADMAP.md b/ROADMAP.md index 26a6f28e3..67620ddd3 100644 --- a/ROADMAP.md +++ b/ROADMAP.md @@ -17,13 +17,6 @@ Although OCI doesn't define a transport method we should have a cryptographic di *Owner:* philips -### Review the need for runtime.json (Target release: v0.3.0) - -There are some discussions about having `runtime.json` being optional for containers and specifying defaults. -Runtimes would use this standard set of defaults for containers and `runtime.json` would provide overrides for fine tuning of these extra host or platform specific settings. - -*Owner:* mrunalp - ### Define Container Lifecycle Containers have a lifecycle and being able to identify and document the lifecycle of a container is very helpful for implementations of the spec. diff --git a/bundle.md b/bundle.md index 6c1045c49..5b1925b2e 100644 --- a/bundle.md +++ b/bundle.md @@ -8,23 +8,17 @@ See also [OS X application bundles](http://en.wikipedia.org/wiki/Bundle_%28OS_X% The definition of a bundle is only concerned with how a container, and its configuration data, are stored on a local file system so that it can be consumed by a compliant runtime. A Standard Container bundle contains all the information needed to load and run a container. -This includes the following three artifacts which MUST all reside in the same directory on the local filesystem: +This includes the following artifacts which MUST all reside in the same directory on the local filesystem: -1. `config.json` : contains host-independent configuration data. -This REQUIRED file, which MUST be named `config.json`, contains settings that are host-independent and application-specific such as security permissions, environment variables and arguments. +1. `config.json` : contains configuration data. +This REQUIRED file, which MUST be named `config.json`. When the bundle is packaged up for distribution, this file MUST be included. See [`config.json`](config.md) for more details. -2. `runtime.json` : contains host-specific configuration data. -This REQUIRED file, which MUST be named `runtime.json`, contains settings that are host-specific such as mount sources and hooks. -The goal is that the bundle can be moved as a unit to another runtime and run the same application once a host-specific `runtime.json` is defined. -When the bundle is packaged up for distribution, this file MUST NOT be included. -See [`runtime.json`](runtime-config.md) for more details. - -3. A directory representing the root filesystem of the container. +2. A directory representing the root filesystem of the container. While the name of this REQUIRED directory may be arbitrary, users should consider using a conventional name, such as `rootfs`. When the bundle is packaged up for distribution, this directory MUST be included. This directory MUST be referenced from within the `config.json` file. -While these three artifacts MUST all be present in a single directory on the local filesystem, that directory itself is not part of the bundle. +While these artifacts MUST all be present in a single directory on the local filesystem, that directory itself is not part of the bundle. In other words, a tar archive of a *bundle* will have these artifacts at the root of the archive, not nested within a top-level directory. diff --git a/config-linux.md b/config-linux.md index 7049e95e8..6a8a5326d 100644 --- a/config-linux.md +++ b/config-linux.md @@ -37,3 +37,553 @@ The following devices and filesystems MUST be made available in each application | /dev/pts | [devpts](https://www.kernel.org/doc/Documentation/filesystems/devpts.txt) | | | /dev/ptmx | [device](https://www.kernel.org/doc/Documentation/filesystems/devpts.txt) | Bind-mount or symlink of /dev/pts/ptmx | | /dev/shm | [tmpfs](https://www.kernel.org/doc/Documentation/filesystems/tmpfs.txt) | | + +## Namespaces + +A namespace wraps a global system resource in an abstraction that makes it appear to the processes within the namespace that they have their own isolated instance of the global resource. +Changes to the global resource are visible to other processes that are members of the namespace, but are invisible to other processes. +For more information, see [the man page](http://man7.org/linux/man-pages/man7/namespaces.7.html). + +Namespaces are specified as an array of entries inside the `namespaces` root field. +The following parameters can be specified to setup namespaces: + +* **`type`** *(string, required)* - namespace type. The following namespaces types are supported: + * **`pid`** processes inside the container will only be able to see other processes inside the same container + * **`network`** the container will have its own network stack + * **`mount`** the container will have an isolated mount table + * **`ipc`** processes inside the container will only be able to communicate to other processes inside the same container via system level IPC + * **`uts`** the container will be able to have its own hostname and domain name + * **`user`** the container will be able to remap user and group IDs from the host to local users and groups within the container + +* **`path`** *(string, optional)* - path to namespace file + +If a path is specified, that particular file is used to join that type of namespace. +Also, when a path is specified, a runtime MUST assume that the setup for that particular namespace has already been done and error out if the config specifies anything else related to that namespace. + +###### Example + +```json + "namespaces": [ + { + "type": "pid", + "path": "/proc/1234/ns/pid" + }, + { + "type": "network", + "path": "/var/run/netns/neta" + }, + { + "type": "mount" + }, + { + "type": "ipc" + }, + { + "type": "uts" + }, + { + "type": "user" + } + ] +``` + +## User namespace mappings + +###### Example + +```json + "uidMappings": [ + { + "hostID": 1000, + "containerID": 0, + "size": 10 + } + ], + "gidMappings": [ + { + "hostID": 1000, + "containerID": 0, + "size": 10 + } + ] +``` + +uid/gid mappings describe the user namespace mappings from the host to the container. +The mappings represent how the bundle `rootfs` expects the user namespace to be setup and the runtime SHOULD NOT modify the permissions on the rootfs to realize the mapping. +*hostID* is the starting uid/gid on the host to be mapped to *containerID* which is the starting uid/gid in the container and *size* refers to the number of ids to be mapped. +There is a limit of 5 mappings which is the Linux kernel hard limit. + +## Devices + +`devices` is an array specifying the list of devices to be created in the container. + +The following parameters can be specified: + +* **`type`** *(char, required)* - type of device: `c`, `b`, `u` or `p`. More info in `man mknod`. + +* **`path`** *(string, optional)* - full path to device inside container + +* **`major, minor`** *(int64, required)* - major, minor numbers for device. More info in `man mknod`. There is a special value: `-1`, which means `*` for `device` cgroup setup. + +* **`permissions`** *(string, optional)* - cgroup permissions for device. A composition of `r` (*read*), `w` (*write*), and `m` (*mknod*). + +* **`fileMode`** *(uint32, optional)* - file mode for device file + +* **`uid`** *(uint32, optional)* - uid of device owner + +* **`gid`** *(uint32, optional)* - gid of device owner + +**`fileMode`**, **`uid`** and **`gid`** are required if **`path`** is given and are otherwise not allowed. + +###### Example + +```json + "devices": [ + { + "path": "/dev/random", + "type": "c", + "major": 1, + "minor": 8, + "permissions": "rwm", + "fileMode": 0666, + "uid": 0, + "gid": 0 + }, + { + "path": "/dev/urandom", + "type": "c", + "major": 1, + "minor": 9, + "permissions": "rwm", + "fileMode": 0666, + "uid": 0, + "gid": 0 + }, + { + "path": "/dev/null", + "type": "c", + "major": 1, + "minor": 3, + "permissions": "rwm", + "fileMode": 0666, + "uid": 0, + "gid": 0 + }, + { + "path": "/dev/zero", + "type": "c", + "major": 1, + "minor": 5, + "permissions": "rwm", + "fileMode": 0666, + "uid": 0, + "gid": 0 + }, + { + "path": "/dev/tty", + "type": "c", + "major": 5, + "minor": 0, + "permissions": "rwm", + "fileMode": 0666, + "uid": 0, + "gid": 0 + }, + { + "path": "/dev/full", + "type": "c", + "major": 1, + "minor": 7, + "permissions": "rwm", + "fileMode": 0666, + "uid": 0, + "gid": 0 + } + ] +``` + +## Control groups + +Also known as cgroups, they are used to restrict resource usage for a container and handle device access. +cgroups provide controls to restrict cpu, memory, IO, pids and network for the container. +For more information, see the [kernel cgroups documentation](https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt). + +The path to the cgroups can be specified in the Spec via `cgroupsPath`. +`cgroupsPath` is expected to be relative to the cgroups mount point. +If `cgroupsPath` is not specified, implementations can define the default cgroup path. +Implementations of the Spec can choose to name cgroups in any manner. +The Spec does not include naming schema for cgroups. +The Spec does not support [split hierarchy](https://www.kernel.org/doc/Documentation/cgroups/unified-hierarchy.txt). +The cgroups will be created if they don't exist. + +###### Example + +```json + "cgroupsPath": "/myRuntime/myContainer" +``` + +`cgroupsPath` can be used to either control the cgroups hierarchy for containers or to run a new process in an existing container. + +You can configure a container's cgroups via the `resources` field of the Linux configuration. +Do not specify `resources` unless limits have to be updated. +For example, to run a new process in an existing container without updating limits, `resources` need not be specified. + +#### Disable out-of-memory killer + +`disableOOMKiller` contains a boolean (`true` or `false`) that enables or disables the Out of Memory killer for a cgroup. +If enabled (`false`), tasks that attempt to consume more memory than they are allowed are immediately killed by the OOM killer. +The OOM killer is enabled by default in every cgroup using the `memory` subsystem. +To disable it, specify a value of `true`. +For more information, see [the memory cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/memory.txt). + +* **`disableOOMKiller`** *(bool, optional)* - enables or disables the OOM killer + +###### Example + +```json + "disableOOMKiller": false +``` + +#### Set oom_score_adj + +`oomScoreAdj` sets heuristic regarding how the process is evaluated by the kernel during memory pressure. +For more information, see [the proc filesystem documentation section 3.1](https://www.kernel.org/doc/Documentation/filesystems/proc.txt). +This is a kernel/system level setting, where as `disableOOMKiller` is scoped for a memory cgroup. +For more information on how these two settings work together, see [the memory cgroup documentation section 10. OOM Contol](https://www.kernel.org/doc/Documentation/cgroups/memory.txt). + +* **`oomScoreAdj`** *(int, optional)* - adjust the oom-killer score + +###### Example + +```json + "oomScoreAdj": 0 +``` + +#### Memory + +`memory` represents the cgroup subsystem `memory` and it's used to set limits on the container's memory usage. +For more information, see [the memory cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/memory.txt). + +The following parameters can be specified to setup the controller: + +* **`limit`** *(uint64, optional)* - sets limit of memory usage + +* **`reservation`** *(uint64, optional)* - sets soft limit of memory usage + +* **`swap`** *(uint64, optional)* - sets limit of memory+Swap usage + +* **`kernel`** *(uint64, optional)* - sets hard limit for kernel memory + +* **`kernelTCP`** *(uint64, optional)* - sets hard limit for kernel memory in tcp using + +* **`swappiness`** *(uint64, optional)* - sets swappiness parameter of vmscan (See sysctl's vm.swappiness) + +###### Example + +```json + "memory": { + "limit": 0, + "reservation": 0, + "swap": 0, + "kernel": 0, + "kernelTCP": 0, + "swappiness": 0 + } +``` + +#### CPU + +`cpu` represents the cgroup subsystems `cpu` and `cpusets`. +For more information, see [the cpusets cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/cpusets.txt). + +The following parameters can be specified to setup the controller: + +* **`shares`** *(uint64, optional)* - specifies a relative share of CPU time available to the tasks in a cgroup + +* **`quota`** *(uint64, optional)* - specifies the total amount of time in microseconds for which all tasks in a cgroup can run during one period (as defined by **`period`** below) + +* **`period`** *(uint64, optional)* - specifies a period of time in microseconds for how regularly a cgroup's access to CPU resources should be reallocated (CFS scheduler only) + +* **`realtimeRuntime`** *(uint64, optional)* - specifies a period of time in microseconds for the longest continuous period in which the tasks in a cgroup have access to CPU resources + +* **`realtimePeriod`** *(uint64, optional)* - same as **`period`** but applies to realtime scheduler only + +* **`cpus`** *(string, optional)* - list of CPUs the container will run in + +* **`mems`** *(string, optional)* - list of Memory Nodes the container will run in + +###### Example + +```json + "cpu": { + "shares": 0, + "quota": 0, + "period": 0, + "realtimeRuntime": 0, + "realtimePeriod": 0, + "cpus": "", + "mems": "" + } +``` + +#### Block IO Controller + +`blockIO` represents the cgroup subsystem `blkio` which implements the block io controller. +For more information, see [the kernel cgroups documentation about blkio](https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt). + +The following parameters can be specified to setup the controller: + +* **`blkioWeight`** *(uint16, optional)* - specifies per-cgroup weight. This is default weight of the group on all devices until and unless overridden by per-device rules. The range is from 10 to 1000. + +* **`blkioLeafWeight`** *(uint16, optional)* - equivalents of `blkioWeight` for the purpose of deciding how much weight tasks in the given cgroup has while competing with the cgroup's child cgroups. The range is from 10 to 1000. + +* **`blkioWeightDevice`** *(array, optional)* - specifies the list of devices which will be bandwidth rate limited. The following parameters can be specified per-device: + * **`major, minor`** *(int64, required)* - major, minor numbers for device. More info in `man mknod`. + * **`weight`** *(uint16, optional)* - bandwidth rate for the device, range is from 10 to 1000 + * **`leafWeight`** *(uint16, optional)* - bandwidth rate for the device while competing with the cgroup's child cgroups, range is from 10 to 1000, CFQ scheduler only + + You must specify at least one of `weight` or `leafWeight` in a given entry, and can specify both. + +* **`blkioThrottleReadBpsDevice`**, **`blkioThrottleWriteBpsDevice`**, **`blkioThrottleReadIOPSDevice`**, **`blkioThrottleWriteIOPSDevice`** *(array, optional)* - specify the list of devices which will be IO rate limited. The following parameters can be specified per-device: + * **`major, minor`** *(int64, required)* - major, minor numbers for device. More info in `man mknod`. + * **`rate`** *(uint64, required)* - IO rate limit for the device + +###### Example + +```json + "blockIO": { + "blkioWeight": 0, + "blkioLeafWeight": 0, + "blkioWeightDevice": [ + { + "major": 8, + "minor": 0, + "weight": 500, + "leafWeight": 300 + }, + { + "major": 8, + "minor": 16, + "weight": 500 + } + ], + "blkioThrottleReadBpsDevice": [ + { + "major": 8, + "minor": 0, + "rate": 600 + } + ], + "blkioThrottleWriteIOPSDevice": [ + { + "major": 8, + "minor": 16, + "rate": 300 + } + ] + } +``` + +#### Huge page limits + +`hugepageLimits` represents the `hugetlb` controller which allows to limit the +HugeTLB usage per control group and enforces the controller limit during page fault. +For more information, see the [kernel cgroups documentation about HugeTLB](https://www.kernel.org/doc/Documentation/cgroups/hugetlb.txt). + +`hugepageLimits` is an array of entries, each having the following structure: + +* **`pageSize`** *(string, required)* - hugepage size + +* **`limit`** *(uint64, required)* - limit in bytes of *hugepagesize* HugeTLB usage + +###### Example + +```json + "hugepageLimits": [ + { + "pageSize": "2MB", + "limit": 9223372036854771712 + } + ] +``` + +#### Network + +`network` represents the cgroup subsystems `net_cls` and `net_prio`. +For more information, see [the net\_cls cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/net_cls.txt) and [the net\_prio cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/net_prio.txt). + +The following parameters can be specified to setup these cgroup controllers: + +* **`classID`** *(uint32, optional)* - is the network class identifier the cgroup's network packets will be tagged with + +* **`priorities`** *(array, optional)* - specifies a list of objects of the priorities assigned to traffic originating from +processes in the group and egressing the system on various interfaces. The following parameters can be specified per-priority: + * **`name`** *(string, required)* - interface name + * **`priority`** *(uint32, required)* - priority applied to the interface + +###### Example + +```json + "network": { + "classID": 1048577, + "priorities": [ + { + "name": "eth0", + "priority": 500 + }, + { + "name": "eth1", + "priority": 1000 + } + ] + } +``` + +#### PIDs + +`pids` represents the cgroup subsystem `pids`. +For more information, see [the pids cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/pids.txt +). + +The following paramters can be specified to setup the controller: + +* **`limit`** *(int64, required)* - specifies the maximum number of tasks in the cgroup + +###### Example + +```json + "pids": { + "limit": 32771 + } +``` + +## Sysctl + +sysctl allows kernel parameters to be modified at runtime for the container. +For more information, see [the man page](http://man7.org/linux/man-pages/man8/sysctl.8.html) + +###### Example + +```json + "sysctl": { + "net.ipv4.ip_forward": "1", + "net.core.somaxconn": "256" + } +``` + +## Rlimits + +rlimits allow setting resource limits. +`type` is a string with a value from those defined in [the man page](http://man7.org/linux/man-pages/man2/setrlimit.2.html). +The kernel enforces the `soft` limit for a resource while the `hard` limit acts as a ceiling for that value that could be set by an unprivileged process. + +###### Example + +```json + "rlimits": [ + { + "type": "RLIMIT_NPROC", + "soft": 1024, + "hard": 102400 + } + ] +``` + +## SELinux process label + +SELinux process label specifies the label with which the processes in a container are run. +For more information about SELinux, see [Selinux documentation](http://selinuxproject.org/page/Main_Page) + +###### Example + +```json + "selinuxProcessLabel": "system_u:system_r:svirt_lxc_net_t:s0:c124,c675" +``` + +## Apparmor profile + +Apparmor profile specifies the name of the apparmor profile that will be used for the container. +For more information about Apparmor, see [Apparmor documentation](https://wiki.ubuntu.com/AppArmor) + +###### Example + +```json + "apparmorProfile": "acme_secure_profile" +``` + +## seccomp + +Seccomp provides application sandboxing mechanism in the Linux kernel. +Seccomp configuration allows one to configure actions to take for matched syscalls and furthermore also allows matching on values passed as arguments to syscalls. +For more information about Seccomp, see [Seccomp kernel documentation](https://www.kernel.org/doc/Documentation/prctl/seccomp_filter.txt) +The actions, architectures, and operators are strings that match the definitions in seccomp.h from [libseccomp](https://github.com/seccomp/libseccomp) and are translated to corresponding values. +A valid list of constants as of Libseccomp v2.2.3 is contained below. + +Architecture Constants +* `SCMP_ARCH_X86` +* `SCMP_ARCH_X86_64` +* `SCMP_ARCH_X32` +* `SCMP_ARCH_ARM` +* `SCMP_ARCH_AARCH64` +* `SCMP_ARCH_MIPS` +* `SCMP_ARCH_MIPS64` +* `SCMP_ARCH_MIPS64N32` +* `SCMP_ARCH_MIPSEL` +* `SCMP_ARCH_MIPSEL64` +* `SCMP_ARCH_MIPSEL64N32` + +Action Constants: +* `SCMP_ACT_KILL` +* `SCMP_ACT_TRAP` +* `SCMP_ACT_ERRNO` +* `SCMP_ACT_TRACE` +* `SCMP_ACT_ALLOW` + +Operator Constants: +* `SCMP_CMP_NE` +* `SCMP_CMP_LT` +* `SCMP_CMP_LE` +* `SCMP_CMP_EQ` +* `SCMP_CMP_GE` +* `SCMP_CMP_GT` +* `SCMP_CMP_MASKED_EQ` + +###### Example + +```json + "seccomp": { + "defaultAction": "SCMP_ACT_ALLOW", + "architectures": [ + "SCMP_ARCH_X86" + ], + "syscalls": [ + { + "name": "getcwd", + "action": "SCMP_ACT_ERRNO" + } + ] + } +``` + +## Rootfs Mount Propagation + +rootfsPropagation sets the rootfs's mount propagation. +Its value is either slave, private, or shared. +[The kernel doc](https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt) has more information about mount propagation. + +###### Example + +```json + "rootfsPropagation": "slave", +``` + +## No new privileges + +Setting `noNewPrivileges` to true prevents the processes in the container from gaining additional privileges. +[The kernel doc](https://www.kernel.org/doc/Documentation/prctl/no_new_privs.txt) has more information on how this is achieved using a prctl system call. + +###### Example + +```json + "noNewPrivileges": true, +``` diff --git a/config.go b/config.go index fecc4f7b9..7861c5638 100644 --- a/config.go +++ b/config.go @@ -15,7 +15,9 @@ type Spec struct { // Hostname is the container's host name. Hostname string `json:"hostname,omitempty"` // Mounts profile configuration for adding mounts to the container's filesystem. - Mounts []MountPoint `json:"mounts"` + Mounts []Mount `json:"mounts"` + // Hooks are the commands run at various lifecycle events of the container. + Hooks Hooks `json:"hooks"` } // Process contains information to start a specific application inside the container. @@ -50,10 +52,33 @@ type Platform struct { Arch string `json:"arch"` } -// MountPoint describes a directory that may be fullfilled by a mount in the runtime.json. -type MountPoint struct { - // Name is a unique descriptive identifier for this mount point. - Name string `json:"name"` - // Path specifies the path of the mount. The path and child directories MUST exist, a runtime MUST NOT create directories automatically to a mount point. - Path string `json:"path"` +// Mount specifies a mount for a container. +type Mount struct { + // Destination is the path where the mount will be placed relative to the container's root. The path and child directories MUST exist, a runtime MUST NOT create directories automatically to a mount point. + Destination string `json:"destination"` + // Type specifies the mount kind. + Type string `json:"type"` + // Source specifies the source path of the mount. In the case of bind mounts on + // linux based systems this would be the file on the host. + Source string `json:"source"` + // Options are fstab style mount options. + Options []string `json:"options,omitempty"` +} + +// Hook specifies a command that is run at a particular event in the lifecycle of a container +type Hook struct { + Path string `json:"path"` + Args []string `json:"args,omitempty"` + Env []string `json:"env,omitempty"` +} + +// Hooks for container setup and teardown +type Hooks struct { + // Prestart is a list of hooks to be run before the container process is executed. + // On Linux, they are run after the container namespaces are created. + Prestart []Hook `json:"prestart,omitempty"` + // Poststart is a list of hooks to be run after the container process is started. + Poststart []Hook `json:"poststart,omitempty"` + // Poststop is a list of hooks to be run after the container process exits. + Poststop []Hook `json:"poststop,omitempty"` } diff --git a/config.md b/config.md index 8dc51c404..884fe32cb 100644 --- a/config.md +++ b/config.md @@ -37,38 +37,52 @@ Each container has exactly one *root filesystem*, specified in the *root* object } ``` -## Mount Points +## Mounts You can add array of mount points inside container as `mounts`. -Each record in this array must have configuration in [runtime config](runtime-config.md#mount-configuration). The runtime MUST mount entries in the listed order. +The parameters are similar to the ones in [the Linux mount system call](http://man7.org/linux/man-pages/man2/mount.2.html). -* **`name`** (string, required) Name of mount point. Used for config lookup. -* **`path`** (string, required) Destination of mount point: path inside container. +* **`destination`** (string, required) Destination of mount point: path inside container. +* **`type`** (string, required) Linux, *filesystemtype* argument supported by the kernel are listed in */proc/filesystems* (e.g., "minix", "ext2", "ext3", "jfs", "xfs", "reiserfs", "msdos", "proc", "nfs", "iso9660"). Windows: ntfs +* **`source`** (string, required) a device name, but can also be a directory name or a dummy. Windows, the volume name that is the target of the mount point. \\?\Volume\{GUID}\ (on Windows source is called target) +* **`options`** (list of strings, optional) in the fstab format [https://wiki.archlinux.org/index.php/Fstab](https://wiki.archlinux.org/index.php/Fstab). -*Example* +### Linux Example ```json "mounts": [ { - "name": "proc", - "path": "/proc" - }, - { - "name": "dev", - "path": "/dev" - }, - { - "name": "devpts", - "path": "/dev/pts" + "destination": "/tmp", + "type": "tmpfs", + "source": "tmpfs", + "options": ["nosuid","strictatime","mode=755","size=65536k"] }, { - "name": "data", - "path": "/data" + "destination": "/data", + "type": "bind", + "source": "/volumes/testing", + "options": ["rbind","rw"] } ] ``` +### Windows Example + +```json +"mounts": [ + "myfancymountpoint": { + "destination": "C:\\Users\\crosbymichael\\My Fancy Mount Point\\", + "type": "ntfs", + "source": "\\\\?\\Volume\\{2eca078d-5cbc-43d3-aff8-7e8511f60d0e}\\", + "options": [] + } +] +``` + +See links for details about [mountvol](http://ss64.com/nt/mountvol.html) and [SetVolumeMountPoint](https://msdn.microsoft.com/en-us/library/windows/desktop/aa365561(v=vs.85).aspx) in Windows. + + ## Process configuration * **`terminal`** (bool, optional) specifies whether you want a terminal attached to that process. Defaults to false. @@ -130,4 +144,72 @@ For Linux-based systems the user structure has the following fields: Interpretation of the platform section of the JSON file is used to find which platform-specific sections may be available in the document. For example, if `os` is set to `linux`, then a JSON object conforming to the [Linux-specific schema](config-linux.md) SHOULD be found at the key `linux` in the `config.json`. +## Hooks + +Lifecycle hooks allow custom events for different points in a container's runtime. +Presently there are `Prestart`, `Poststart` and `Poststop`. + +* [`Prestart`](#prestart) is a list of hooks to be run before the container process is executed +* [`Poststart`](#poststart) is a list of hooks to be run immediately after the container process is started +* [`Poststop`](#poststop) is a list of hooks to be run after the container process exits + +Hooks allow one to run code before/after various lifecycle events of the container. +Hooks MUST be called in the listed order. +The state of the container is passed to the hooks over stdin, so the hooks could get the information they need to do their work. + +Hook paths are absolute and are executed from the host's filesystem. + +### Prestart + +The pre-start hooks are called after the container process is spawned, but before the user supplied command is executed. +They are called after the container namespaces are created on Linux, so they provide an opportunity to customize the container. +In Linux, for e.g., the network namespace could be configured in this hook. + +If a hook returns a non-zero exit code, then an error including the exit code and the stderr is returned to the caller and the container is torn down. + +### Poststart + +The post-start hooks are called after the user process is started. +For example this hook can notify user that real process is spawned. + +If a hook returns a non-zero exit code, then an error is logged and the remaining hooks are executed. + +### Poststop + +The post-stop hooks are called after the container process is stopped. +Cleanup or debugging could be performed in such a hook. +If a hook returns a non-zero exit code, then an error is logged and the remaining hooks are executed. + +*Example* + +```json + "hooks" : { + "prestart": [ + { + "path": "/usr/bin/fix-mounts", + "args": ["fix-mounts", "arg1", "arg2"], + "env": [ "key1=value1"] + }, + { + "path": "/usr/bin/setup-network" + } + ], + "poststart": [ + { + "path": "/usr/bin/notify-start" + } + ], + "poststop": [ + { + "path": "/usr/sbin/cleanup.sh", + "args": ["cleanup.sh", "-f"] + } + ] + } +``` + +`path` is required for a hook. +`args` and `env` are optional. +The semantics are the same as `Path`, `Args` and `Env` in [golang Cmd](https://golang.org/pkg/os/exec/#Cmd). + [uts-namespace]: http://man7.org/linux/man-pages/man7/namespaces.7.html diff --git a/config_linux.go b/config_linux.go index a715bb567..0a9ebaf5c 100644 --- a/config_linux.go +++ b/config_linux.go @@ -1,5 +1,10 @@ package specs +import "os" + +// LinuxStateDirectory holds the container's state information +const LinuxStateDirectory = "/run/opencontainer/containers" + // LinuxSpec is the full specification for linux containers. type LinuxSpec struct { Spec @@ -11,6 +16,35 @@ type LinuxSpec struct { type Linux struct { // Capabilities are linux capabilities that are kept for the container. Capabilities []string `json:"capabilities"` + // UIDMapping specifies user mappings for supporting user namespaces on linux. + UIDMappings []IDMapping `json:"uidMappings,omitempty"` + // GIDMapping specifies group mappings for supporting user namespaces on linux. + GIDMappings []IDMapping `json:"gidMappings,omitempty"` + // Rlimits specifies rlimit options to apply to the container's process. + Rlimits []Rlimit `json:"rlimits,omitempty"` + // Sysctl are a set of key value pairs that are set for the container on start + Sysctl map[string]string `json:"sysctl,omitempty"` + // Resources contain cgroup information for handling resource constraints + // for the container + Resources *Resources `json:"resources,omitempty"` + // CgroupsPath specifies the path to cgroups that are created and/or joined by the container. + // The path is expected to be relative to the cgroups mountpoint. + // If resources are specified, the cgroups at CgroupsPath will be updated based on resources. + CgroupsPath *string `json:"cgroupsPath,omitempty"` + // Namespaces contains the namespaces that are created and/or joined by the container + Namespaces []Namespace `json:"namespaces"` + // Devices are a list of device nodes that are created and enabled for the container + Devices []Device `json:"devices"` + // ApparmorProfile specified the apparmor profile for the container. + ApparmorProfile string `json:"apparmorProfile"` + // SelinuxProcessLabel specifies the selinux context that the container process is run as. + SelinuxProcessLabel string `json:"selinuxProcessLabel"` + // Seccomp specifies the seccomp security settings for the container. + Seccomp Seccomp `json:"seccomp"` + // RootfsPropagation is the rootfs mount propagation mode for the container. + RootfsPropagation string `json:"rootfsPropagation,omitempty"` + // NoNewPrivileges controls whether additional privileges could be gained by processes in the container. + NoNewPrivileges bool `json:"noNewPrivileges,omitempty"` } // User specifies linux specific user and group information for the container's @@ -23,3 +57,263 @@ type User struct { // AdditionalGids are additional group ids set for the container's process. AdditionalGids []uint32 `json:"additionalGids,omitempty"` } + +// Namespace is the configuration for a linux namespace +type Namespace struct { + // Type is the type of Linux namespace + Type NamespaceType `json:"type"` + // Path is a path to an existing namespace persisted on disk that can be joined + // and is of the same type + Path string `json:"path,omitempty"` +} + +// NamespaceType is one of the linux namespaces +type NamespaceType string + +const ( + // PIDNamespace for isolating process IDs + PIDNamespace NamespaceType = "pid" + // NetworkNamespace for isolating network devices, stacks, ports, etc + NetworkNamespace = "network" + // MountNamespace for isolating mount points + MountNamespace = "mount" + // IPCNamespace for isolating System V IPC, POSIX message queues + IPCNamespace = "ipc" + // UTSNamespace for isolating hostname and NIS domain name + UTSNamespace = "uts" + // UserNamespace for isolating user and group IDs + UserNamespace = "user" +) + +// IDMapping specifies UID/GID mappings +type IDMapping struct { + // HostID is the UID/GID of the host user or group + HostID uint32 `json:"hostID"` + // ContainerID is the UID/GID of the container's user or group + ContainerID uint32 `json:"containerID"` + // Size is the length of the range of IDs mapped between the two namespaces + Size uint32 `json:"size"` +} + +// Rlimit type and restrictions +type Rlimit struct { + // Type of the rlimit to set + Type string `json:"type"` + // Hard is the hard limit for the specified type + Hard uint64 `json:"hard"` + // Soft is the soft limit for the specified type + Soft uint64 `json:"soft"` +} + +// HugepageLimit structure corresponds to limiting kernel hugepages +type HugepageLimit struct { + // Pagesize is the hugepage size + Pagesize *string `json:"pageSize,omitempty"` + // Limit is the limit of "hugepagesize" hugetlb usage + Limit *uint64 `json:"limit,omitempty"` +} + +// InterfacePriority for network interfaces +type InterfacePriority struct { + // Name is the name of the network interface + Name string `json:"name"` + // Priority for the interface + Priority uint32 `json:"priority"` +} + +// blockIODevice holds major:minor format supported in blkio cgroup +type blockIODevice struct { + // Major is the device's major number. + Major int64 `json:"major"` + // Minor is the device's minor number. + Minor int64 `json:"minor"` +} + +// WeightDevice struct holds a `major:minor weight` pair for blkioWeightDevice +type WeightDevice struct { + blockIODevice + // Weight is the bandwidth rate for the device, range is from 10 to 1000 + Weight *uint16 `json:"weight,omitempty"` + // LeafWeight is the bandwidth rate for the device while competing with the cgroup's child cgroups, range is from 10 to 1000, CFQ scheduler only + LeafWeight *uint16 `json:"leafWeight,omitempty"` +} + +// ThrottleDevice struct holds a `major:minor rate_per_second` pair +type ThrottleDevice struct { + blockIODevice + // Rate is the IO rate limit per cgroup per device + Rate *uint64 `json:"rate,omitempty"` +} + +// BlockIO for Linux cgroup 'blkio' resource management +type BlockIO struct { + // Specifies per cgroup weight, range is from 10 to 1000 + Weight *uint16 `json:"blkioWeight,omitempty"` + // Specifies tasks' weight in the given cgroup while competing with the cgroup's child cgroups, range is from 10 to 1000, CFQ scheduler only + LeafWeight *uint16 `json:"blkioLeafWeight,omitempty"` + // Weight per cgroup per device, can override BlkioWeight + WeightDevice []WeightDevice `json:"blkioWeightDevice,omitempty"` + // IO read rate limit per cgroup per device, bytes per second + ThrottleReadBpsDevice []ThrottleDevice `json:"blkioThrottleReadBpsDevice,omitempty"` + // IO write rate limit per cgroup per device, bytes per second + ThrottleWriteBpsDevice []ThrottleDevice `json:"blkioThrottleWriteBpsDevice,omitempty"` + // IO read rate limit per cgroup per device, IO per second + ThrottleReadIOPSDevice []ThrottleDevice `json:"blkioThrottleReadIOPSDevice,omitempty"` + // IO write rate limit per cgroup per device, IO per second + ThrottleWriteIOPSDevice []ThrottleDevice `json:"blkioThrottleWriteIOPSDevice,omitempty"` +} + +// Memory for Linux cgroup 'memory' resource management +type Memory struct { + // Memory limit (in bytes). + Limit *uint64 `json:"limit,omitempty"` + // Memory reservation or soft_limit (in bytes). + Reservation *uint64 `json:"reservation,omitempty"` + // Total memory limit (memory + swap). + Swap *uint64 `json:"swap,omitempty"` + // Kernel memory limit (in bytes). + Kernel *uint64 `json:"kernel,omitempty"` + // Kernel memory limit for tcp (in bytes) + KernelTCP *uint64 `json:"kernelTCP"` + // How aggressive the kernel will swap memory pages. Range from 0 to 100. + Swappiness *uint64 `json:"swappiness,omitempty"` +} + +// CPU for Linux cgroup 'cpu' resource management +type CPU struct { + // CPU shares (relative weight (ratio) vs. other cgroups with cpu shares). + Shares *uint64 `json:"shares,omitempty"` + // CPU hardcap limit (in usecs). Allowed cpu time in a given period. + Quota *uint64 `json:"quota,omitempty"` + // CPU period to be used for hardcapping (in usecs). + Period *uint64 `json:"period,omitempty"` + // How much time realtime scheduling may use (in usecs). + RealtimeRuntime *uint64 `json:"realtimeRuntime,omitempty"` + // CPU period to be used for realtime scheduling (in usecs). + RealtimePeriod *uint64 `json:"realtimePeriod,omitempty"` + // CPUs to use within the cpuset. Default is to use any CPU available. + Cpus *string `json:"cpus,omitempty"` + // List of memory nodes in the cpuset. Default is to use any available memory node. + Mems *string `json:"mems,omitempty"` +} + +// Pids for Linux cgroup 'pids' resource management (Linux 4.3) +type Pids struct { + // Maximum number of PIDs. Default is "no limit". + Limit *int64 `json:"limit,omitempty"` +} + +// Network identification and priority configuration +type Network struct { + // Set class identifier for container's network packets + ClassID *uint32 `json:"classID"` + // Set priority of network traffic for container + Priorities []InterfacePriority `json:"priorities,omitempty"` +} + +// Resources has container runtime resource constraints +type Resources struct { + // DisableOOMKiller disables the OOM killer for out of memory conditions + DisableOOMKiller *bool `json:"disableOOMKiller,omitempty"` + // Specify an oom_score_adj for the container. + OOMScoreAdj *int `json:"oomScoreAdj,omitempty"` + // Memory restriction configuration + Memory *Memory `json:"memory,omitempty"` + // CPU resource restriction configuration + CPU *CPU `json:"cpu,omitempty"` + // Task resource restriction configuration. + Pids *Pids `json:"pids,omitempty"` + // BlockIO restriction configuration + BlockIO *BlockIO `json:"blockIO,omitempty"` + // Hugetlb limit (in bytes) + HugepageLimits []HugepageLimit `json:"hugepageLimits,omitempty"` + // Network restriction configuration + Network *Network `json:"network,omitempty"` +} + +// Device represents the information on a Linux special device file +type Device struct { + // Path to the device. + Path string `json:"path"` + // Device type, block, char, etc. + Type rune `json:"type"` + // Major is the device's major number. + Major int64 `json:"major"` + // Minor is the device's minor number. + Minor int64 `json:"minor"` + // Cgroup permissions format, rwm. + Permissions string `json:"permissions"` + // FileMode permission bits for the device. + FileMode os.FileMode `json:"fileMode"` + // UID of the device. + UID uint32 `json:"uid"` + // Gid of the device. + GID uint32 `json:"gid"` +} + +// Seccomp represents syscall restrictions +type Seccomp struct { + DefaultAction Action `json:"defaultAction"` + Architectures []Arch `json:"architectures"` + Syscalls []Syscall `json:"syscalls,omitempty"` +} + +// Arch used for additional architectures +type Arch string + +// Additional architectures permitted to be used for system calls +// By default only the native architecture of the kernel is permitted +const ( + ArchX86 Arch = "SCMP_ARCH_X86" + ArchX86_64 Arch = "SCMP_ARCH_X86_64" + ArchX32 Arch = "SCMP_ARCH_X32" + ArchARM Arch = "SCMP_ARCH_ARM" + ArchAARCH64 Arch = "SCMP_ARCH_AARCH64" + ArchMIPS Arch = "SCMP_ARCH_MIPS" + ArchMIPS64 Arch = "SCMP_ARCH_MIPS64" + ArchMIPS64N32 Arch = "SCMP_ARCH_MIPS64N32" + ArchMIPSEL Arch = "SCMP_ARCH_MIPSEL" + ArchMIPSEL64 Arch = "SCMP_ARCH_MIPSEL64" + ArchMIPSEL64N32 Arch = "SCMP_ARCH_MIPSEL64N32" +) + +// Action taken upon Seccomp rule match +type Action string + +// Define actions for Seccomp rules +const ( + ActKill Action = "SCMP_ACT_KILL" + ActTrap Action = "SCMP_ACT_TRAP" + ActErrno Action = "SCMP_ACT_ERRNO" + ActTrace Action = "SCMP_ACT_TRACE" + ActAllow Action = "SCMP_ACT_ALLOW" +) + +// Operator used to match syscall arguments in Seccomp +type Operator string + +// Define operators for syscall arguments in Seccomp +const ( + OpNotEqual Operator = "SCMP_CMP_NE" + OpLessThan Operator = "SCMP_CMP_LT" + OpLessEqual Operator = "SCMP_CMP_LE" + OpEqualTo Operator = "SCMP_CMP_EQ" + OpGreaterEqual Operator = "SCMP_CMP_GE" + OpGreaterThan Operator = "SCMP_CMP_GT" + OpMaskedEqual Operator = "SCMP_CMP_MASKED_EQ" +) + +// Arg used for matching specific syscall arguments in Seccomp +type Arg struct { + Index uint `json:"index"` + Value uint64 `json:"value"` + ValueTwo uint64 `json:"valueTwo"` + Op Operator `json:"op"` +} + +// Syscall is used to match a syscall in Seccomp +type Syscall struct { + Name string `json:"name"` + Action Action `json:"action"` + Args []Arg `json:"args,omitempty"` +} diff --git a/glossary.md b/glossary.md index 00075621c..f9d11c4f5 100644 --- a/glossary.md +++ b/glossary.md @@ -6,7 +6,7 @@ A [directory structure](bundle.md) that is written ahead of time, distributed, a ## Configuration -The [`config.json`](config.md) and [`runtime.json`](runtime-config.md) files in a [bundle](#bundle) which define the intended [container](#container) and container process. +The [`config.json`](config.md) file in a [bundle](#bundle) which defines the intended [container](#container) and container process. ## Container diff --git a/runtime-config-linux.md b/runtime-config-linux.md deleted file mode 100644 index b716bfa29..000000000 --- a/runtime-config-linux.md +++ /dev/null @@ -1,553 +0,0 @@ -# Linux-specific Runtime Configuration - -## Namespaces - -A namespace wraps a global system resource in an abstraction that makes it appear to the processes within the namespace that they have their own isolated instance of the global resource. -Changes to the global resource are visible to other processes that are members of the namespace, but are invisible to other processes. -For more information, see [the man page](http://man7.org/linux/man-pages/man7/namespaces.7.html). - -Namespaces are specified as an array of entries inside the `namespaces` root field. -The following parameters can be specified to setup namespaces: - -* **`type`** *(string, required)* - namespace type. The following namespaces types are supported: - * **`pid`** processes inside the container will only be able to see other processes inside the same container - * **`network`** the container will have its own network stack - * **`mount`** the container will have an isolated mount table - * **`ipc`** processes inside the container will only be able to communicate to other processes inside the same container via system level IPC - * **`uts`** the container will be able to have its own hostname and domain name - * **`user`** the container will be able to remap user and group IDs from the host to local users and groups within the container - -* **`path`** *(string, optional)* - path to namespace file - -If a path is specified, that particular file is used to join that type of namespace. -Also, when a path is specified, a runtime MUST assume that the setup for that particular namespace has already been done and error out if the config specifies anything else related to that namespace. - -###### Example - -```json - "namespaces": [ - { - "type": "pid", - "path": "/proc/1234/ns/pid" - }, - { - "type": "network", - "path": "/var/run/netns/neta" - }, - { - "type": "mount" - }, - { - "type": "ipc" - }, - { - "type": "uts" - }, - { - "type": "user" - } - ] -``` - -## User namespace mappings - -###### Example - -```json - "uidMappings": [ - { - "hostID": 1000, - "containerID": 0, - "size": 10 - } - ], - "gidMappings": [ - { - "hostID": 1000, - "containerID": 0, - "size": 10 - } - ] -``` - -uid/gid mappings describe the user namespace mappings from the host to the container. -The mappings represent how the bundle `rootfs` expects the user namespace to be setup and the runtime SHOULD NOT modify the permissions on the rootfs to realize the mapping. -*hostID* is the starting uid/gid on the host to be mapped to *containerID* which is the starting uid/gid in the container and *size* refers to the number of ids to be mapped. -There is a limit of 5 mappings which is the Linux kernel hard limit. - -## Devices - -`devices` is an array specifying the list of devices to be created in the container. - -The following parameters can be specified: - -* **`type`** *(char, required)* - type of device: `c`, `b`, `u` or `p`. More info in `man mknod`. - -* **`path`** *(string, optional)* - full path to device inside container - -* **`major, minor`** *(int64, required)* - major, minor numbers for device. More info in `man mknod`. There is a special value: `-1`, which means `*` for `device` cgroup setup. - -* **`permissions`** *(string, optional)* - cgroup permissions for device. A composition of `r` (*read*), `w` (*write*), and `m` (*mknod*). - -* **`fileMode`** *(uint32, optional)* - file mode for device file - -* **`uid`** *(uint32, optional)* - uid of device owner - -* **`gid`** *(uint32, optional)* - gid of device owner - -**`fileMode`**, **`uid`** and **`gid`** are required if **`path`** is given and are otherwise not allowed. - -###### Example - -```json - "devices": [ - { - "path": "/dev/random", - "type": "c", - "major": 1, - "minor": 8, - "permissions": "rwm", - "fileMode": 0666, - "uid": 0, - "gid": 0 - }, - { - "path": "/dev/urandom", - "type": "c", - "major": 1, - "minor": 9, - "permissions": "rwm", - "fileMode": 0666, - "uid": 0, - "gid": 0 - }, - { - "path": "/dev/null", - "type": "c", - "major": 1, - "minor": 3, - "permissions": "rwm", - "fileMode": 0666, - "uid": 0, - "gid": 0 - }, - { - "path": "/dev/zero", - "type": "c", - "major": 1, - "minor": 5, - "permissions": "rwm", - "fileMode": 0666, - "uid": 0, - "gid": 0 - }, - { - "path": "/dev/tty", - "type": "c", - "major": 5, - "minor": 0, - "permissions": "rwm", - "fileMode": 0666, - "uid": 0, - "gid": 0 - }, - { - "path": "/dev/full", - "type": "c", - "major": 1, - "minor": 7, - "permissions": "rwm", - "fileMode": 0666, - "uid": 0, - "gid": 0 - } - ] -``` - -## Control groups - -Also known as cgroups, they are used to restrict resource usage for a container and handle device access. -cgroups provide controls to restrict cpu, memory, IO, pids and network for the container. -For more information, see the [kernel cgroups documentation](https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt). - -The path to the cgroups can be specified in the Spec via `cgroupsPath`. -`cgroupsPath` is expected to be relative to the cgroups mount point. -If `cgroupsPath` is not specified, implementations can define the default cgroup path. -Implementations of the Spec can choose to name cgroups in any manner. -The Spec does not include naming schema for cgroups. -The Spec does not support [split hierarchy](https://www.kernel.org/doc/Documentation/cgroups/unified-hierarchy.txt). -The cgroups will be created if they don't exist. - -###### Example - -```json - "cgroupsPath": "/myRuntime/myContainer" -``` - -`cgroupsPath` can be used to either control the cgroups hierarchy for containers or to run a new process in an existing container. - -You can configure a container's cgroups via the `resources` field of the Linux configuration. -Do not specify `resources` unless limits have to be updated. -For example, to run a new process in an existing container without updating limits, `resources` need not be specified. - -#### Disable out-of-memory killer - -`disableOOMKiller` contains a boolean (`true` or `false`) that enables or disables the Out of Memory killer for a cgroup. -If enabled (`false`), tasks that attempt to consume more memory than they are allowed are immediately killed by the OOM killer. -The OOM killer is enabled by default in every cgroup using the `memory` subsystem. -To disable it, specify a value of `true`. -For more information, see [the memory cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/memory.txt). - -* **`disableOOMKiller`** *(bool, optional)* - enables or disables the OOM killer - -###### Example - -```json - "disableOOMKiller": false -``` - -#### Set oom_score_adj - -`oomScoreAdj` sets heuristic regarding how the process is evaluated by the kernel during memory pressure. -For more information, see [the proc filesystem documentation section 3.1](https://www.kernel.org/doc/Documentation/filesystems/proc.txt). -This is a kernel/system level setting, where as `disableOOMKiller` is scoped for a memory cgroup. -For more information on how these two settings work together, see [the memory cgroup documentation section 10. OOM Contol](https://www.kernel.org/doc/Documentation/cgroups/memory.txt). - -* **`oomScoreAdj`** *(int, optional)* - adjust the oom-killer score - -###### Example - -###### Example - -```json - "oomScoreAdj": 0 -``` - -#### Memory - -`memory` represents the cgroup subsystem `memory` and it's used to set limits on the container's memory usage. -For more information, see [the memory cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/memory.txt). - -The following parameters can be specified to setup the controller: - -* **`limit`** *(uint64, optional)* - sets limit of memory usage - -* **`reservation`** *(uint64, optional)* - sets soft limit of memory usage - -* **`swap`** *(uint64, optional)* - sets limit of memory+Swap usage - -* **`kernel`** *(uint64, optional)* - sets hard limit for kernel memory - -* **`kernelTCP`** *(uint64, optional)* - sets hard limit for kernel memory in tcp using - -* **`swappiness`** *(uint64, optional)* - sets swappiness parameter of vmscan (See sysctl's vm.swappiness) - -###### Example - -```json - "memory": { - "limit": 0, - "reservation": 0, - "swap": 0, - "kernel": 0, - "kernelTCP": 0, - "swappiness": 0 - } -``` - -#### CPU - -`cpu` represents the cgroup subsystems `cpu` and `cpusets`. -For more information, see [the cpusets cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/cpusets.txt). - -The following parameters can be specified to setup the controller: - -* **`shares`** *(uint64, optional)* - specifies a relative share of CPU time available to the tasks in a cgroup - -* **`quota`** *(uint64, optional)* - specifies the total amount of time in microseconds for which all tasks in a cgroup can run during one period (as defined by **`period`** below) - -* **`period`** *(uint64, optional)* - specifies a period of time in microseconds for how regularly a cgroup's access to CPU resources should be reallocated (CFS scheduler only) - -* **`realtimeRuntime`** *(uint64, optional)* - specifies a period of time in microseconds for the longest continuous period in which the tasks in a cgroup have access to CPU resources - -* **`realtimePeriod`** *(uint64, optional)* - same as **`period`** but applies to realtime scheduler only - -* **`cpus`** *(string, optional)* - list of CPUs the container will run in - -* **`mems`** *(string, optional)* - list of Memory Nodes the container will run in - -###### Example - -```json - "cpu": { - "shares": 0, - "quota": 0, - "period": 0, - "realtimeRuntime": 0, - "realtimePeriod": 0, - "cpus": "", - "mems": "" - } -``` - -#### Block IO Controller - -`blockIO` represents the cgroup subsystem `blkio` which implements the block io controller. -For more information, see [the kernel cgroups documentation about blkio](https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt). - -The following parameters can be specified to setup the controller: - -* **`blkioWeight`** *(uint16, optional)* - specifies per-cgroup weight. This is default weight of the group on all devices until and unless overridden by per-device rules. The range is from 10 to 1000. - -* **`blkioLeafWeight`** *(uint16, optional)* - equivalents of `blkioWeight` for the purpose of deciding how much weight tasks in the given cgroup has while competing with the cgroup's child cgroups. The range is from 10 to 1000. - -* **`blkioWeightDevice`** *(array, optional)* - specifies the list of devices which will be bandwidth rate limited. The following parameters can be specified per-device: - * **`major, minor`** *(int64, required)* - major, minor numbers for device. More info in `man mknod`. - * **`weight`** *(uint16, optional)* - bandwidth rate for the device, range is from 10 to 1000 - * **`leafWeight`** *(uint16, optional)* - bandwidth rate for the device while competing with the cgroup's child cgroups, range is from 10 to 1000, CFQ scheduler only - - You must specify at least one of `weight` or `leafWeight` in a given entry, and can specify both. - -* **`blkioThrottleReadBpsDevice`**, **`blkioThrottleWriteBpsDevice`**, **`blkioThrottleReadIOPSDevice`**, **`blkioThrottleWriteIOPSDevice`** *(array, optional)* - specify the list of devices which will be IO rate limited. The following parameters can be specified per-device: - * **`major, minor`** *(int64, required)* - major, minor numbers for device. More info in `man mknod`. - * **`rate`** *(uint64, required)* - IO rate limit for the device - -###### Example - -```json - "blockIO": { - "blkioWeight": 0, - "blkioLeafWeight": 0, - "blkioWeightDevice": [ - { - "major": 8, - "minor": 0, - "weight": 500, - "leafWeight": 300 - }, - { - "major": 8, - "minor": 16, - "weight": 500 - } - ], - "blkioThrottleReadBpsDevice": [ - { - "major": 8, - "minor": 0, - "rate": 600 - } - ], - "blkioThrottleWriteIOPSDevice": [ - { - "major": 8, - "minor": 16, - "rate": 300 - } - ] - } -``` - -#### Huge page limits - -`hugepageLimits` represents the `hugetlb` controller which allows to limit the -HugeTLB usage per control group and enforces the controller limit during page fault. -For more information, see the [kernel cgroups documentation about HugeTLB](https://www.kernel.org/doc/Documentation/cgroups/hugetlb.txt). - -`hugepageLimits` is an array of entries, each having the following structure: - -* **`pageSize`** *(string, required)* - hugepage size - -* **`limit`** *(uint64, required)* - limit in bytes of *hugepagesize* HugeTLB usage - -###### Example - -```json - "hugepageLimits": [ - { - "pageSize": "2MB", - "limit": 9223372036854771712 - } - ] -``` - -#### Network - -`network` represents the cgroup subsystems `net_cls` and `net_prio`. -For more information, see [the net\_cls cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/net_cls.txt) and [the net\_prio cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/net_prio.txt). - -The following parameters can be specified to setup these cgroup controllers: - -* **`classID`** *(uint32, optional)* - is the network class identifier the cgroup's network packets will be tagged with - -* **`priorities`** *(array, optional)* - specifies a list of objects of the priorities assigned to traffic originating from -processes in the group and egressing the system on various interfaces. The following parameters can be specified per-priority: - * **`name`** *(string, required)* - interface name - * **`priority`** *(uint32, required)* - priority applied to the interface - -###### Example - -```json - "network": { - "classID": 1048577, - "priorities": [ - { - "name": "eth0", - "priority": 500 - }, - { - "name": "eth1", - "priority": 1000 - } - ] - } -``` - -#### PIDs - -`pids` represents the cgroup subsystem `pids`. -For more information, see [the pids cgroup man page](https://www.kernel.org/doc/Documentation/cgroups/pids.txt -). - -The following paramters can be specified to setup the controller: - -* **`limit`** *(int64, required)* - specifies the maximum number of tasks in the cgroup - -###### Example - -```json - "pids": { - "limit": 32771 - } -``` - -## Sysctl - -sysctl allows kernel parameters to be modified at runtime for the container. -For more information, see [the man page](http://man7.org/linux/man-pages/man8/sysctl.8.html) - -###### Example - -```json - "sysctl": { - "net.ipv4.ip_forward": "1", - "net.core.somaxconn": "256" - } -``` - -## Rlimits - -rlimits allow setting resource limits. -`type` is a string with a value from those defined in [the man page](http://man7.org/linux/man-pages/man2/setrlimit.2.html). -The kernel enforces the `soft` limit for a resource while the `hard` limit acts as a ceiling for that value that could be set by an unprivileged process. - -###### Example - -```json - "rlimits": [ - { - "type": "RLIMIT_NPROC", - "soft": 1024, - "hard": 102400 - } - ] -``` - -## SELinux process label - -SELinux process label specifies the label with which the processes in a container are run. -For more information about SELinux, see [Selinux documentation](http://selinuxproject.org/page/Main_Page) - -###### Example - -```json - "selinuxProcessLabel": "system_u:system_r:svirt_lxc_net_t:s0:c124,c675" -``` - -## Apparmor profile - -Apparmor profile specifies the name of the apparmor profile that will be used for the container. -For more information about Apparmor, see [Apparmor documentation](https://wiki.ubuntu.com/AppArmor) - -###### Example - -```json - "apparmorProfile": "acme_secure_profile" -``` - -## seccomp - -Seccomp provides application sandboxing mechanism in the Linux kernel. -Seccomp configuration allows one to configure actions to take for matched syscalls and furthermore also allows matching on values passed as arguments to syscalls. -For more information about Seccomp, see [Seccomp kernel documentation](https://www.kernel.org/doc/Documentation/prctl/seccomp_filter.txt) -The actions, architectures, and operators are strings that match the definitions in seccomp.h from [libseccomp](https://github.com/seccomp/libseccomp) and are translated to corresponding values. -A valid list of constants as of Libseccomp v2.2.3 is contained below. - -Architecture Constants -* `SCMP_ARCH_X86` -* `SCMP_ARCH_X86_64` -* `SCMP_ARCH_X32` -* `SCMP_ARCH_ARM` -* `SCMP_ARCH_AARCH64` -* `SCMP_ARCH_MIPS` -* `SCMP_ARCH_MIPS64` -* `SCMP_ARCH_MIPS64N32` -* `SCMP_ARCH_MIPSEL` -* `SCMP_ARCH_MIPSEL64` -* `SCMP_ARCH_MIPSEL64N32` - -Action Constants: -* `SCMP_ACT_KILL` -* `SCMP_ACT_TRAP` -* `SCMP_ACT_ERRNO` -* `SCMP_ACT_TRACE` -* `SCMP_ACT_ALLOW` - -Operator Constants: -* `SCMP_CMP_NE` -* `SCMP_CMP_LT` -* `SCMP_CMP_LE` -* `SCMP_CMP_EQ` -* `SCMP_CMP_GE` -* `SCMP_CMP_GT` -* `SCMP_CMP_MASKED_EQ` - -###### Example - -```json - "seccomp": { - "defaultAction": "SCMP_ACT_ALLOW", - "architectures": [ - "SCMP_ARCH_X86" - ], - "syscalls": [ - { - "name": "getcwd", - "action": "SCMP_ACT_ERRNO" - } - ] - } -``` - -## Rootfs Mount Propagation - -rootfsPropagation sets the rootfs's mount propagation. -Its value is either slave, private, or shared. -[The kernel doc](https://www.kernel.org/doc/Documentation/filesystems/sharedsubtree.txt) has more information about mount propagation. - -###### Example - -```json - "rootfsPropagation": "slave", -``` - -## No new privileges - -Setting `noNewPrivileges` to true prevents the processes in the container from gaining additional privileges. -[The kernel doc](https://www.kernel.org/doc/Documentation/prctl/no_new_privs.txt) has more information on how this is achieved using a prctl system call. - -###### Example - -```json - "noNewPrivileges": true, -``` diff --git a/runtime-config.md b/runtime-config.md deleted file mode 100644 index a02a08bea..000000000 --- a/runtime-config.md +++ /dev/null @@ -1,122 +0,0 @@ -# Runtime Configuration - -## Hooks - -Lifecycle hooks allow custom events for different points in a container's runtime. -Presently there are `Prestart`, `Poststart` and `Poststop`. - -* [`Prestart`](#prestart) is a list of hooks to be run before the container process is executed -* [`Poststart`](#poststart) is a list of hooks to be run immediately after the container process is started -* [`Poststop`](#poststop) is a list of hooks to be run after the container process exits - -Hooks allow one to run code before/after various lifecycle events of the container. -Hooks MUST be called in the listed order. -The state of the container is passed to the hooks over stdin, so the hooks could get the information they need to do their work. - -Hook paths are absolute and are executed from the host's filesystem. - -### Prestart - -The pre-start hooks are called after the container process is spawned, but before the user supplied command is executed. -They are called after the container namespaces are created on Linux, so they provide an opportunity to customize the container. -In Linux, for e.g., the network namespace could be configured in this hook. - -If a hook returns a non-zero exit code, then an error including the exit code and the stderr is returned to the caller and the container is torn down. - -### Poststart - -The post-start hooks are called after the user process is started. -For example this hook can notify user that real process is spawned. - -If a hook returns a non-zero exit code, then an error is logged and the remaining hooks are executed. - -### Poststop - -The post-stop hooks are called after the container process is stopped. -Cleanup or debugging could be performed in such a hook. -If a hook returns a non-zero exit code, then an error is logged and the remaining hooks are executed. - -*Example* - -```json - "hooks" : { - "prestart": [ - { - "path": "/usr/bin/fix-mounts", - "args": ["fix-mounts", "arg1", "arg2"], - "env": [ "key1=value1"] - }, - { - "path": "/usr/bin/setup-network" - } - ], - "poststart": [ - { - "path": "/usr/bin/notify-start" - } - ], - "poststop": [ - { - "path": "/usr/sbin/cleanup.sh", - "args": ["cleanup.sh", "-f"] - } - ] - } -``` - -`path` is required for a hook. -`args` and `env` are optional. -The semantics are the same as `Path`, `Args` and `Env` in [golang Cmd](https://golang.org/pkg/os/exec/#Cmd). - -## Mount Configuration - -Additional filesystems can be declared as "mounts", specified in the *mounts* object. -Keys in this object are names of mount points from portable config. -Values are objects with configuration of mount points. -The parameters are similar to the ones in [the Linux mount system call](http://man7.org/linux/man-pages/man2/mount.2.html). -Only [mounts from the portable config](config.md#mount-points) will be mounted. - -* **`type`** (string, required) Linux, *filesystemtype* argument supported by the kernel are listed in */proc/filesystems* (e.g., "minix", "ext2", "ext3", "jfs", "xfs", "reiserfs", "msdos", "proc", "nfs", "iso9660"). Windows: ntfs -* **`source`** (string, required) a device name, but can also be a directory name or a dummy. Windows, the volume name that is the target of the mount point. \\?\Volume\{GUID}\ (on Windows source is called target) -* **`options`** (list of strings, optional) in the fstab format [https://wiki.archlinux.org/index.php/Fstab](https://wiki.archlinux.org/index.php/Fstab). - -*Example (Linux)* - -```json -"mounts": { - "proc": { - "type": "proc", - "source": "proc", - "options": [] - }, - "dev": { - "type": "tmpfs", - "source": "tmpfs", - "options": ["nosuid","strictatime","mode=755","size=65536k"] - }, - "devpts": { - "type": "devpts", - "source": "devpts", - "options": ["nosuid","noexec","newinstance","ptmxmode=0666","mode=0620","gid=5"] - }, - "data": { - "type": "bind", - "source": "/volumes/testing", - "options": ["rbind","rw"] - } -} -``` - -*Example (Windows)* - -```json -"mounts": { - "myfancymountpoint": { - "type": "ntfs", - "source": "\\\\?\\Volume\\{2eca078d-5cbc-43d3-aff8-7e8511f60d0e}\\", - "options": [] - } -} -``` - -See links for details about [mountvol](http://ss64.com/nt/mountvol.html) and [SetVolumeMountPoint](https://msdn.microsoft.com/en-us/library/windows/desktop/aa365561(v=vs.85).aspx) in Windows. diff --git a/runtime.md b/runtime.md index 090f9ea1e..12d6c94cf 100644 --- a/runtime.md +++ b/runtime.md @@ -38,8 +38,8 @@ This is provided so that consumers can find the container's configuration and ro The lifecycle describes the timeline of events that happen from when a container is created to when it ceases to exist. 1. OCI compliant runtime is invoked by passing the bundle path as argument. -2. The container's runtime environment is created according to the configuration in `config.json` and `runtime.json`. - Any updates to `config.json` or `runtime.json` after container is running do not affect the container. +2. The container's runtime environment is created according to the configuration in [`config.json`](config.md). + Any updates to `config.json` after container is running do not affect the container. 3. The container's state.json file is written to the filesystem. 4. The prestart hooks are invoked by the runtime. If any prestart hook fails, then the container is stopped and the lifecycle continues at step 8. @@ -56,4 +56,4 @@ Note: The lifecycle is a WIP and it will evolve as we have more use cases and mo ## Hooks -See [runtime configuration for hooks](./runtime-config.md) +See [runtime configuration for hooks](./config.md#hooks) diff --git a/runtime_config.go b/runtime_config.go deleted file mode 100644 index 931f912c4..000000000 --- a/runtime_config.go +++ /dev/null @@ -1,42 +0,0 @@ -package specs - -// RuntimeSpec contains host-specific configuration information for -// a container. This information must not be included when the bundle -// is packaged for distribution. -type RuntimeSpec struct { - // Mounts is a mapping of names to mount configurations. - // Which mounts will be mounted and where should be chosen with MountPoints - // in Spec. - Mounts map[string]Mount `json:"mounts"` - // Hooks are the commands run at various lifecycle events of the container. - Hooks Hooks `json:"hooks"` -} - -// Hook specifies a command that is run at a particular event in the lifecycle of a container -type Hook struct { - Path string `json:"path"` - Args []string `json:"args,omitempty"` - Env []string `json:"env,omitempty"` -} - -// Hooks for container setup and teardown -type Hooks struct { - // Prestart is a list of hooks to be run before the container process is executed. - // On Linux, they are run after the container namespaces are created. - Prestart []Hook `json:"prestart,omitempty"` - // Poststart is a list of hooks to be run after the container process is started. - Poststart []Hook `json:"poststart,omitempty"` - // Poststop is a list of hooks to be run after the container process exits. - Poststop []Hook `json:"poststop,omitempty"` -} - -// Mount specifies a mount for a container -type Mount struct { - // Type specifies the mount kind. - Type string `json:"type"` - // Source specifies the source path of the mount. In the case of bind mounts on - // linux based systems this would be the file on the host. - Source string `json:"source"` - // Options are fstab style mount options. - Options []string `json:"options,omitempty"` -} diff --git a/runtime_config_linux.go b/runtime_config_linux.go deleted file mode 100644 index baa2c50e9..000000000 --- a/runtime_config_linux.go +++ /dev/null @@ -1,306 +0,0 @@ -package specs - -import "os" - -// LinuxStateDirectory holds the container's state information -const LinuxStateDirectory = "/run/opencontainer/containers" - -// LinuxRuntimeSpec is the full specification for linux containers. -type LinuxRuntimeSpec struct { - RuntimeSpec - // LinuxRuntime is platform specific configuration for linux based containers. - Linux LinuxRuntime `json:"linux"` -} - -// LinuxRuntime hosts the Linux-only runtime information -type LinuxRuntime struct { - // UIDMapping specifies user mappings for supporting user namespaces on linux. - UIDMappings []IDMapping `json:"uidMappings,omitempty"` - // GIDMapping specifies group mappings for supporting user namespaces on linux. - GIDMappings []IDMapping `json:"gidMappings,omitempty"` - // Rlimits specifies rlimit options to apply to the container's process. - Rlimits []Rlimit `json:"rlimits,omitempty"` - // Sysctl are a set of key value pairs that are set for the container on start - Sysctl map[string]string `json:"sysctl,omitempty"` - // Resources contain cgroup information for handling resource constraints - // for the container - Resources *Resources `json:"resources,omitempty"` - // CgroupsPath specifies the path to cgroups that are created and/or joined by the container. - // The path is expected to be relative to the cgroups mountpoint. - // If resources are specified, the cgroups at CgroupsPath will be updated based on resources. - CgroupsPath *string `json:"cgroupsPath,omitempty"` - // Namespaces contains the namespaces that are created and/or joined by the container - Namespaces []Namespace `json:"namespaces"` - // Devices are a list of device nodes that are created and enabled for the container - Devices []Device `json:"devices"` - // ApparmorProfile specified the apparmor profile for the container. - ApparmorProfile string `json:"apparmorProfile"` - // SelinuxProcessLabel specifies the selinux context that the container process is run as. - SelinuxProcessLabel string `json:"selinuxProcessLabel"` - // Seccomp specifies the seccomp security settings for the container. - Seccomp Seccomp `json:"seccomp"` - // RootfsPropagation is the rootfs mount propagation mode for the container. - RootfsPropagation string `json:"rootfsPropagation,omitempty"` - // NoNewPrivileges controls whether additional privileges could be gained by processes in the container. - NoNewPrivileges bool `json:"noNewPrivileges,omitempty"` -} - -// Namespace is the configuration for a linux namespace -type Namespace struct { - // Type is the type of Linux namespace - Type NamespaceType `json:"type"` - // Path is a path to an existing namespace persisted on disk that can be joined - // and is of the same type - Path string `json:"path,omitempty"` -} - -// NamespaceType is one of the linux namespaces -type NamespaceType string - -const ( - // PIDNamespace for isolating process IDs - PIDNamespace NamespaceType = "pid" - // NetworkNamespace for isolating network devices, stacks, ports, etc - NetworkNamespace = "network" - // MountNamespace for isolating mount points - MountNamespace = "mount" - // IPCNamespace for isolating System V IPC, POSIX message queues - IPCNamespace = "ipc" - // UTSNamespace for isolating hostname and NIS domain name - UTSNamespace = "uts" - // UserNamespace for isolating user and group IDs - UserNamespace = "user" -) - -// IDMapping specifies UID/GID mappings -type IDMapping struct { - // HostID is the UID/GID of the host user or group - HostID uint32 `json:"hostID"` - // ContainerID is the UID/GID of the container's user or group - ContainerID uint32 `json:"containerID"` - // Size is the length of the range of IDs mapped between the two namespaces - Size uint32 `json:"size"` -} - -// Rlimit type and restrictions -type Rlimit struct { - // Type of the rlimit to set - Type string `json:"type"` - // Hard is the hard limit for the specified type - Hard uint64 `json:"hard"` - // Soft is the soft limit for the specified type - Soft uint64 `json:"soft"` -} - -// HugepageLimit structure corresponds to limiting kernel hugepages -type HugepageLimit struct { - // Pagesize is the hugepage size - Pagesize *string `json:"pageSize,omitempty"` - // Limit is the limit of "hugepagesize" hugetlb usage - Limit *uint64 `json:"limit,omitempty"` -} - -// InterfacePriority for network interfaces -type InterfacePriority struct { - // Name is the name of the network interface - Name string `json:"name"` - // Priority for the interface - Priority uint32 `json:"priority"` -} - -// blockIODevice holds major:minor format supported in blkio cgroup -type blockIODevice struct { - // Major is the device's major number. - Major int64 `json:"major"` - // Minor is the device's minor number. - Minor int64 `json:"minor"` -} - -// WeightDevice struct holds a `major:minor weight` pair for blkioWeightDevice -type WeightDevice struct { - blockIODevice - // Weight is the bandwidth rate for the device, range is from 10 to 1000 - Weight *uint16 `json:"weight,omitempty"` - // LeafWeight is the bandwidth rate for the device while competing with the cgroup's child cgroups, range is from 10 to 1000, CFQ scheduler only - LeafWeight *uint16 `json:"leafWeight,omitempty"` -} - -// ThrottleDevice struct holds a `major:minor rate_per_second` pair -type ThrottleDevice struct { - blockIODevice - // Rate is the IO rate limit per cgroup per device - Rate *uint64 `json:"rate,omitempty"` -} - -// BlockIO for Linux cgroup 'blkio' resource management -type BlockIO struct { - // Specifies per cgroup weight, range is from 10 to 1000 - Weight *uint16 `json:"blkioWeight,omitempty"` - // Specifies tasks' weight in the given cgroup while competing with the cgroup's child cgroups, range is from 10 to 1000, CFQ scheduler only - LeafWeight *uint16 `json:"blkioLeafWeight,omitempty"` - // Weight per cgroup per device, can override BlkioWeight - WeightDevice []WeightDevice `json:"blkioWeightDevice,omitempty"` - // IO read rate limit per cgroup per device, bytes per second - ThrottleReadBpsDevice []ThrottleDevice `json:"blkioThrottleReadBpsDevice,omitempty"` - // IO write rate limit per cgroup per device, bytes per second - ThrottleWriteBpsDevice []ThrottleDevice `json:"blkioThrottleWriteBpsDevice,omitempty"` - // IO read rate limit per cgroup per device, IO per second - ThrottleReadIOPSDevice []ThrottleDevice `json:"blkioThrottleReadIOPSDevice,omitempty"` - // IO write rate limit per cgroup per device, IO per second - ThrottleWriteIOPSDevice []ThrottleDevice `json:"blkioThrottleWriteIOPSDevice,omitempty"` -} - -// Memory for Linux cgroup 'memory' resource management -type Memory struct { - // Memory limit (in bytes). - Limit *uint64 `json:"limit,omitempty"` - // Memory reservation or soft_limit (in bytes). - Reservation *uint64 `json:"reservation,omitempty"` - // Total memory limit (memory + swap). - Swap *uint64 `json:"swap,omitempty"` - // Kernel memory limit (in bytes). - Kernel *uint64 `json:"kernel,omitempty"` - // Kernel memory limit for tcp (in bytes) - KernelTCP *uint64 `json:"kernelTCP"` - // How aggressive the kernel will swap memory pages. Range from 0 to 100. - Swappiness *uint64 `json:"swappiness,omitempty"` -} - -// CPU for Linux cgroup 'cpu' resource management -type CPU struct { - // CPU shares (relative weight (ratio) vs. other cgroups with cpu shares). - Shares *uint64 `json:"shares,omitempty"` - // CPU hardcap limit (in usecs). Allowed cpu time in a given period. - Quota *uint64 `json:"quota,omitempty"` - // CPU period to be used for hardcapping (in usecs). - Period *uint64 `json:"period,omitempty"` - // How much time realtime scheduling may use (in usecs). - RealtimeRuntime *uint64 `json:"realtimeRuntime,omitempty"` - // CPU period to be used for realtime scheduling (in usecs). - RealtimePeriod *uint64 `json:"realtimePeriod,omitempty"` - // CPUs to use within the cpuset. Default is to use any CPU available. - Cpus *string `json:"cpus,omitempty"` - // List of memory nodes in the cpuset. Default is to use any available memory node. - Mems *string `json:"mems,omitempty"` -} - -// Pids for Linux cgroup 'pids' resource management (Linux 4.3) -type Pids struct { - // Maximum number of PIDs. Default is "no limit". - Limit *int64 `json:"limit,omitempty"` -} - -// Network identification and priority configuration -type Network struct { - // Set class identifier for container's network packets - ClassID *uint32 `json:"classID"` - // Set priority of network traffic for container - Priorities []InterfacePriority `json:"priorities,omitempty"` -} - -// Resources has container runtime resource constraints -type Resources struct { - // DisableOOMKiller disables the OOM killer for out of memory conditions - DisableOOMKiller *bool `json:"disableOOMKiller,omitempty"` - // Specify an oom_score_adj for the container. - OOMScoreAdj *int `json:"oomScoreAdj,omitempty"` - // Memory restriction configuration - Memory *Memory `json:"memory,omitempty"` - // CPU resource restriction configuration - CPU *CPU `json:"cpu,omitempty"` - // Task resource restriction configuration. - Pids *Pids `json:"pids,omitempty"` - // BlockIO restriction configuration - BlockIO *BlockIO `json:"blockIO,omitempty"` - // Hugetlb limit (in bytes) - HugepageLimits []HugepageLimit `json:"hugepageLimits,omitempty"` - // Network restriction configuration - Network *Network `json:"network,omitempty"` -} - -// Device represents the information on a Linux special device file -type Device struct { - // Path to the device. - Path string `json:"path"` - // Device type, block, char, etc. - Type rune `json:"type"` - // Major is the device's major number. - Major int64 `json:"major"` - // Minor is the device's minor number. - Minor int64 `json:"minor"` - // Cgroup permissions format, rwm. - Permissions string `json:"permissions"` - // FileMode permission bits for the device. - FileMode os.FileMode `json:"fileMode"` - // UID of the device. - UID uint32 `json:"uid"` - // Gid of the device. - GID uint32 `json:"gid"` -} - -// Seccomp represents syscall restrictions -type Seccomp struct { - DefaultAction Action `json:"defaultAction"` - Architectures []Arch `json:"architectures"` - Syscalls []Syscall `json:"syscalls,omitempty"` -} - -// Arch used for additional architectures -type Arch string - -// Additional architectures permitted to be used for system calls -// By default only the native architecture of the kernel is permitted -const ( - ArchX86 Arch = "SCMP_ARCH_X86" - ArchX86_64 Arch = "SCMP_ARCH_X86_64" - ArchX32 Arch = "SCMP_ARCH_X32" - ArchARM Arch = "SCMP_ARCH_ARM" - ArchAARCH64 Arch = "SCMP_ARCH_AARCH64" - ArchMIPS Arch = "SCMP_ARCH_MIPS" - ArchMIPS64 Arch = "SCMP_ARCH_MIPS64" - ArchMIPS64N32 Arch = "SCMP_ARCH_MIPS64N32" - ArchMIPSEL Arch = "SCMP_ARCH_MIPSEL" - ArchMIPSEL64 Arch = "SCMP_ARCH_MIPSEL64" - ArchMIPSEL64N32 Arch = "SCMP_ARCH_MIPSEL64N32" -) - -// Action taken upon Seccomp rule match -type Action string - -// Define actions for Seccomp rules -const ( - ActKill Action = "SCMP_ACT_KILL" - ActTrap Action = "SCMP_ACT_TRAP" - ActErrno Action = "SCMP_ACT_ERRNO" - ActTrace Action = "SCMP_ACT_TRACE" - ActAllow Action = "SCMP_ACT_ALLOW" -) - -// Operator used to match syscall arguments in Seccomp -type Operator string - -// Define operators for syscall arguments in Seccomp -const ( - OpNotEqual Operator = "SCMP_CMP_NE" - OpLessThan Operator = "SCMP_CMP_LT" - OpLessEqual Operator = "SCMP_CMP_LE" - OpEqualTo Operator = "SCMP_CMP_EQ" - OpGreaterEqual Operator = "SCMP_CMP_GE" - OpGreaterThan Operator = "SCMP_CMP_GT" - OpMaskedEqual Operator = "SCMP_CMP_MASKED_EQ" -) - -// Arg used for matching specific syscall arguments in Seccomp -type Arg struct { - Index uint `json:"index"` - Value uint64 `json:"value"` - ValueTwo uint64 `json:"valueTwo"` - Op Operator `json:"op"` -} - -// Syscall is used to match a syscall in Seccomp -type Syscall struct { - Name string `json:"name"` - Action Action `json:"action"` - Args []Arg `json:"args,omitempty"` -} diff --git a/style.md b/style.md index 4f4b0f642..e9e86d050 100644 --- a/style.md +++ b/style.md @@ -15,7 +15,7 @@ The redundancy reduction from removing the namespacing prefix is not useful enou So we have a consistent way to identify unset values ([source][optional-pointer]). [capabilities]: config-linux.md#capabilities -[class-id]: runtime-config-linux.md#network +[class-id]: config-linux.md#network [integer-over-hex]: https://github.com/opencontainers/specs/pull/267#discussion_r48360013 [keep-prefix]: https://github.com/opencontainers/specs/pull/159#issuecomment-138728337 [optional-pointer]: https://github.com/opencontainers/specs/pull/233#discussion_r47829711