To run dockerd
inside a docker container, two things are needed:
- Run the container as privileged (we could probably do better! expose capabilities instead).
- Mount
/var/lib/docker
as volume, here an anonymous volume. This is because of limitations of what you can do with the overlay system docker is setup to use.
cluster:
name: cluster
privateKey: cluster-key
machines:
- count: 1
spec:
image: quay.io/footloose/centos7
name: node%d
portMappings:
- containerPort: 22
privileged: true
volumes:
- type: volume
destination: /var/lib/docker
You can then install and run docker on the machine:
$ footloose create
$ footloose ssh root@node0
# yum install -y docker iptables
[...]
# systemctl start docker
# docker run busybox echo 'Hello, World!'
Hello, World!