feat: First version (#1)

.github/settings.yml

@@ -1,6 +1,6 @@
 # https://developer.github.com/v3/repos/#edit
 repository:
- name: docker-$$IMAGE_NAME$$
+ name: docker-swarm-local-network-connector
  description: ""
  homepage: https://homecentr.github.io/
  private: false

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ on:
  pull_request:
 
 env:
- IMAGE_NAME: "homecentr/$$IMAGE_NAME$$"
+ IMAGE_NAME: "homecentr/swarm-local-network-connector"
 
 jobs:
  build:

.github/workflows/ci_cd.yml

@@ -5,7 +5,7 @@ on:
  - master
 
 env:
- IMAGE_NAME: "homecentr/$$IMAGE_NAME$$"
+ IMAGE_NAME: "homecentr/swarm-local-network-connector"
 
 jobs:
  build:

.github/workflows/regular_scan.yml

@@ -4,7 +4,7 @@ on:
  - cron: '0 6 * * *'
 
 env:
- IMAGE_NAME: "homecentr/$$IMAGE_NAME$$"
+ IMAGE_NAME: "homecentr/swarm-local-network-connector"
 
 jobs:
  build:

Dockerfile

@@ -1 +1,18 @@
-FROM alpine
+FROM golang:1.14.0-alpine as build
+
+RUN apk add --no-cache git=2.24.1-r0
+
+COPY ./src /go/src/github.com/homecentr/docker-swarm-local-network-connector
+
+WORKDIR /go/src/github.com/homecentr/docker-swarm-local-network-connector
+
+RUN go get ./... && \
+ go build
+
+FROM alpine:3.11.3
+
+COPY --from=build /go/src/github.com/homecentr/docker-swarm-local-network-connector/docker-swarm-local-network-connector /swarm-local-network-connector
+
+RUN chmod a+x /swarm-local-network-connector
+
+ENTRYPOINT [ "/swarm-local-network-connector" ]

README.md

@@ -1,5 +1,5 @@
-# HomeCentr - $$IMAGE_NAME$$
-Template repository for Docker container repositories
+# HomeCentr - swarm-local-network-connector
+Connector process which monitors for newly created containers and connectes them to the network specified in the label. This is a workaround to solve the problem when Docker Swarm does not pass explicit IP address when connecting container to a macvlan network or other local scoped network drivers.
 
 ## Project status
 

docker-compose.yml

@@ -1,6 +1,6 @@
 version: "3.7"
 services:
- $$IMAGE_NAME$$:
+ swarm-local-network-connector:
  build: .
- image: homecentr/$$IMAGE_NAME$$
+ image: homecentr/swarm-local-network-connector
  restart: unless-stopped

example/docker-compose.yml

@@ -0,0 +1,6 @@
+version: "3.7"
+services:
+ nginx:
+ image: nginx
+ labels:
+ io.homecentr.local-networks: "[{ \"Network\": \"macvlan\", \"Config\": { \"IPAMConfig\": { \"IPV4Address\": \"192.168.2.199\" } } }]" 

package.json

@@ -1,15 +1,15 @@
 { 
- "name": "homecentr-$$IMAGE_NAME$$",
+ "name": "homecentr-swarm-local-network-connector",
  "version": "1.0.0",
  "description": "",
  "repository": {
  "type": "git",
- "url": "git+https://github.com/homecentr/docker-$$IMAGE_NAME$$.git"
+ "url": "git+https://github.com/homecentr/docker-swarm-local-network-connector.git"
  },
  "author": "",
  "license": "MIT",
  "bugs": {
- "url": "https://github.com/homecentr/docker-$$IMAGE_NAME$$/issues"
+ "url": "https://github.com/homecentr/docker-swarm-local-network-connector/issues"
  },
- "homepage": "https://github.com/homecentr/docker-$$IMAGE_NAME$$#readme"
+ "homepage": "https://github.com/homecentr/docker-swarm-local-network-connector#readme"
 }

src/Connector.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+ "context"
+
+ "github.com/docker/docker/client"
+)
+
+type Connector struct {
+ cli *client.Client
+ eventsContextCancel *context.CancelFunc
+}
+
+func NewConnector(cli *client.Client) *Connector {
+ result := new(Connector)
+ result.cli = cli
+
+ return result
+}

src/Connector_Events.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+ "context"
+
+ "github.com/docker/docker/api/types"
+)
+
+func (c *Connector) listenToContainerEvents(ctx context.Context) error {
+ msgs, errs := c.cli.Events(ctx, types.EventsOptions{})
+
+ for {
+ select {
+ case err := <-errs:
+ print(err)
+ case msg := <-msgs:
+ if msg.Type == "container" && msg.Action == "create" {
+ c.handleContainer(ctx, msg.ID)
+ }
+ }
+ }
+}

src/Connector_ExistingContainers.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+ "context"
+
+ "github.com/docker/docker/api/types"
+)
+
+func (c *Connector) verifyExistingContainersConnected(ctx context.Context) error {
+ containers, err := c.cli.ContainerList(ctx, types.ContainerListOptions{})
+
+ if err != nil {
+ return err
+ }
+
+ for _, container := range containers {
+ err = c.handleContainer(ctx, container.ID)
+
+ if err != nil {
+ return err
+ }
+ }
+
+ return nil
+}

src/Connector_HandleContainer.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+ "context"
+
+ "github.com/sirupsen/logrus"
+
+ types "github.com/docker/docker/api/types"
+)
+
+func (c *Connector) handleContainer(ctx context.Context, containerId string) error {
+ logrus.Debugf("Checking container %s", containerId)
+
+ json, err := c.cli.ContainerInspect(ctx, containerId)
+
+ if err != nil {
+ return err
+ }
+
+ networkConfigs := getNetworkConfiguration(&json)
+
+ if networkConfigs == nil {
+ logrus.Debugf("The container %s does not have a valid label, skipping...", containerId)
+ return nil
+ }
+
+ logrus.Infof("Found valid label on container %s", containerId)
+
+ for _, networkConfig := range networkConfigs {
+ if networkConfig.NetworkName == "" {
+ logrus.Warnf("Skipping entry with empty network name on container %s.", containerId)
+ continue
+ }
+
+ networkId, err := getNetworkId(c.cli, ctx, networkConfig.NetworkName)
+
+ if err != nil {
+ logrus.Warnf("Network with name %s does not exist, skipping this network.", networkConfig.NetworkName)
+ continue
+ }
+
+ if isContainerConnectedToNetwork(&json, networkId) {
+ logrus.Debugf("Container %s is already connected to the network %s (%s).", containerId, networkConfig.NetworkName, networkId)
+
+ continue
+ }
+
+ logrus.Infof("Connecting container %s to the network %s (%s)...", containerId, networkConfig.NetworkName, networkId)
+ err = c.connectContainerToNetwork(ctx, containerId, networkId, &networkConfig)
+
+ if err != nil {
+ logrus.Warnf("Connecting container %s to the network %s (%s) has failed: %s.", containerId, networkConfig.NetworkName, networkId, err)
+ continue
+ }
+ }
+
+ return nil
+}
+
+func isContainerConnectedToNetwork(containerJson *types.ContainerJSON, networkId string) bool {
+ for _, network := range (*containerJson).NetworkSettings.Networks {
+ if network.NetworkID == networkId {
+ return true
+ }
+ }
+
+ return false
+}
+
+func (c *Connector) connectContainerToNetwork(ctx context.Context, containerId string, networkId string, config *networkConfiguration) error {
+ settings := (*config).EndpointSettings
+ c.cli.NetworkConnect(ctx, networkId, containerId, &settings)
+ return nil
+}

src/Connector_StartStop.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+ "context"
+
+ "github.com/sirupsen/logrus"
+)
+
+func (c *Connector) Start() {
+ ctx := context.Background()
+ eventsContext, cancel := context.WithCancel(ctx)
+
+ c.eventsContextCancel = &cancel
+
+ logrus.Infof("Subscribing to container create events...")
+ go c.listenToContainerEvents(eventsContext)
+
+ logrus.Infof("Verifying existing containers are connected...")
+ c.verifyExistingContainersConnected(context.Background())
+}
+
+func (c *Connector) Stop() {
+ (*c.eventsContextCancel)()
+}

src/ContainerLabels.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+ "encoding/json"
+
+ "github.com/sirupsen/logrus"
+
+ types "github.com/docker/docker/api/types"
+ "github.com/docker/docker/api/types/network"
+)
+
+const LabelName string = "io.homecentr.local-networks"
+
+type networkConfiguration struct {
+ NetworkName string `json:"Network"`
+ EndpointSettings network.EndpointSettings `json:"Config"`
+}
+
+func getNetworkConfiguration(containerInfo *types.ContainerJSON) []networkConfiguration {
+ labels := (*containerInfo).Config.Labels
+
+ if value, exists := labels[LabelName]; exists {
+ var result []networkConfiguration
+
+ err := json.Unmarshal([]byte(value), &result)
+
+ if err != nil {
+ logrus.Warnf("The container %s has invalid label value which cannot be deserialized as json.", containerInfo.ID)
+
+ return nil
+ }
+
+ return result
+ }
+
+ return nil
+}

src/Networking.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+ "context"
+ "errors"
+
+ "github.com/docker/docker/api/types"
+ "github.com/docker/docker/api/types/filters"
+ "github.com/docker/docker/client"
+)
+
+func getNetworkId(cli *client.Client, ctx context.Context, networkName string) (string, error) {
+ filterArgs := filters.NewArgs()
+ filterArgs.Add("name", networkName)
+
+ options := types.NetworkListOptions{
+ Filters: filterArgs,
+ }
+
+ matches, err := cli.NetworkList(ctx, options)
+
+ if err != nil {
+ return "", err
+ }
+
+ if len(matches) == 0 {
+ return "", errors.New("The network " + networkName + " could not be found.")
+ }
+
+ if len(matches) > 1 {
+ return "", errors.New("The are multiple networks with name " + networkName + ".")
+ }
+
+ return matches[0].ID, nil
+}