To build a Docker image you need to have the whole vyos-build repository, not only a folder with Dockerfile, because some files from this repository are required for building.

Docker image with VyOS can be built on Linux host with the next command:

docker build --compress --file Dockerfile \
  --tag vyos:version-`date -u +%Y%m%d%H%M%S` \
  --build-arg BUILD_DATE="`date -u --rfc-3339=seconds`" \
  --build-arg VYOS_VERSION=version \
  --build-arg DEBIAN_VERSION=debian \
  --progress plain ..

Or, if you want to rebuild completely from the scratch (without cache):

docker build --no-cache --pull --compress --file Dockerfile \
  --tag vyos:version-`date -u +%Y%m%d%H%M%S` \
  --build-arg BUILD_DATE="`date -u --rfc-3339=seconds`" \
  --build-arg VYOS_VERSION=version \
  --build-arg DEBIAN_VERSION=debian \
  --progress plain ..

NOTE: You must use proper version value for DEBIAN_VERSION variable. It can be only jessie (for VyOS 1.2) or buster (for VyOS 1.3).

Run Container

Docker container with VyOS can be running with the next command:

docker run --privileged --detach \
  --volume /lib/modules:/lib/modules \
  --name vyos_inside_docker vyos:version

You need to use the --privileged flag because the system actively interacts with a host kernel to perform routing operations and tune networking options.

Experimantal: You can limit access to some system resources with:

docker run --privileged --detach \
   --tmpfs /tmp \
   --tmpfs /run \
   --tmpfs /run/lock \
   --volume /lib/modules:/lib/modules:ro \
   --volume /sys/fs/cgroup:/sys/fs/cgroup:ro \
   --name vyos_inside_docker vyos:version

Log into container

To open VyOS CLI, you can use SSH connection to the Docker container or run on host:

docker exec -it vyos_inside_docker su vyos

Troubleshooting

If in VyOS appears IPv6-related errors, for example, it cannot assign an IPv6 address for an interface, it is necessary to enable IPv6 support in Docker.

This can be done, by editing /etc/docker/daemon.json:

{
    "ipv6": true,
    "fixed-cidr-v6": "fe80::/64"
}