QEMU in a docker container for running x64 virtual machines (even on ARM platforms).
It uses high-performance QEMU options (like KVM acceleration, kernel-mode networking, IO threading, etc.) to achieve near-native speed.
- Multi-platform
- KVM acceleration
- Web-based viewer
Via docker-compose.yml
version: "3"
services:
qemu:
container_name: qemu
image: qemux/qemu-docker
environment:
BOOT: "https://dl-cdn.alpinelinux.org/alpine/v3.19/releases/x86_64/alpine-virt-3.19.0-x86_64.iso"
devices:
- /dev/kvm
cap_add:
- NET_ADMIN
ports:
- 8006:8006
stop_grace_period: 2m
restart: unless-stopped
Via docker run
docker run -it --rm -e "BOOT=https://example.com/image.iso" -p 8006:8006 --device=/dev/kvm --cap-add NET_ADMIN qemux/qemu-docker
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You begin by setting the
BOOT
environment variable to the URL of an ISO image of the OS you want to install:environment: BOOT: "https://dl-cdn.alpinelinux.org/alpine/v3.19/releases/x86_64/alpine-virt-3.19.0-x86_64.iso"
Start the container and connect to port 8006 of the container in your web browser.
After the download is finished, you will see the screen and can interact with it via the keyboard and mouse. Enjoy your new machine, and don't forget to star this repo!
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By default, a single CPU core and 1 GB of RAM are allocated to the container.
To increase this, add the following environment variables:
environment: RAM_SIZE: "4G" CPU_CORES: "4"
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To expand the default size of 16 GB, add the
DISK_SIZE
setting to your compose file and set it to your preferred capacity:environment: DISK_SIZE: "128G"
This can also be used to resize the existing disk to a larger capacity without any data loss.
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To change the storage location, include the following bind mount in your compose file:
volumes: - /var/qemu:/storage
Replace the example path
/var/qemu
with the desired storage folder. -
For emulating Windows, there is dockur/windows, which is more dedicated to that purpose. It has all the same features as this container, but additionally includes all the necessary drivers, and it will even automatically download the correct ISO image from the Microsoft servers.
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To verify if your system supports KVM, run the following commands:
sudo apt install cpu-checker sudo kvm-ok
If you receive an error from
kvm-ok
indicating that KVM acceleration can't be used, check the virtualization settings in the BIOS. -
By default, the container uses bridge networking, which shares the IP address with the host.
If you want to assign an individual IP address to the container, you can create a macvlan network as follows:
docker network create -d macvlan \ --subnet=192.168.0.0/24 \ --gateway=192.168.0.1 \ --ip-range=192.168.0.100/28 \ -o parent=eth0 vlan
Be sure to modify these values to match your local subnet.
Once you have created the network, change your compose file to look as follows:
services: qemu: container_name: qemu ..<snip>.. networks: vlan: ipv4_address: 192.168.0.100 networks: vlan: external: true
An added benefit of this approach is that you won't have to perform any port mapping anymore, since all ports will be exposed by default.
Please note that this IP address won't be accessible from the Docker host due to the design of macvlan, which doesn't permit communication between the two. If this is a concern, you need to create a second macvlan as a workaround.
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After configuring the container for macvlan (see above), it is possible for the VM to become part of your home network by requesting an IP from your router, just like your other devices.
To enable this feature, add the following lines to your compose file:
environment: DHCP: "Y" device_cgroup_rules: - 'c *:* rwm'
Please note that in this mode, the container and the VM will each have their own separate IPs. The container will keep the macvlan IP, and the VM will be reachable via the DHCP IP.
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It is possible to pass-through disk devices directly by adding them to your compose file in this way:
environment: DEVICE: "/dev/sda" DEVICE2: "/dev/sdb" devices: - /dev/sda - /dev/sdb
Use
DEVICE
if you want it to become your main drive, and useDEVICE2
and higher to add them as secondary drives. -
To enable UEFI booting, add the following line to your compose file:
environment: BOOT_MODE: "uefi"
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You can create the
ARGUMENTS
environment variable to provide additional arguments to QEMU at runtime:environment: ARGUMENTS: "-device usb-tablet"