Intro

Multipass is described as a mini cloud on your computer. It’s a pretty elegant tool based on the great design of LXD, another tool from Canonical that I really enjoy. I prefer using Multipass for my local docker host needs over Docker Desktop For Mac. Part of this based on my experience as a dev tooling Engineering Manager. Docker Desktop For Mac always seemed to be slow and bulky and this can cause some issues when rolling out as a dev tool at scale. On the other hand, multipass seems much less resource intensive by comparison. Furthermore, coupled with cloud-init you can use declarative files to bootstrap a multipass server.

This guide will walk you through installing Multipass and configuring a Docker server to use with your Mac’s docker client. Essentially, a lightweight alternative to Docker Desktop For Mac.

Tutorial

Install Multipass and Docker Client

brew install multipass docker

Create a cloud-init yaml

Create and save cloud-init yaml to a desired location:

vim $HOME/docker4mac.yaml

Copy the below yaml:

---
users:
  - name: ubuntu
    sudo: ALL=(ALL) NOPASSWD:ALL
package_update: true
write_files:
- content: |
    {"hosts": ["tcp://0.0.0.0:2375", "unix:///var/run/docker.sock"]}
  path: /etc/docker/daemon.json
- content: |
    [Service]
    ExecStart=
    ExecStart=/usr/bin/dockerd
  path: /etc/systemd/system/docker.service.d/override.conf
packages:
  - docker
  - avahi-daemon
  - apt-transport-https
  - ca-certificates
  - curl
  - gnupg
  - lsb-release
runcmd:
  - sudo curl -fsSL https://get.docker.com | sudo bash
  - sudo systemctl enable docker
  - sudo groupadd docker
  - sudo usermod -aG docker ubuntu
  - sudo systemctl daemon-reload
  - systemctl restart docker.service

Create a docker host in multipass

multipass launch -c 2 -m 1G -d 25G -n docker lts --cloud-init $HOME/docker4mac.yaml

Add DOCKER_HOST environment variable to .zshrc

echo "export DOCKER_HOST=tcp://$(multipass info docker | grep IPv4 | awk '{print $2}'):2375" >> $HOME/.zshrc

At this point you should have docker ready to go on your Mac. Test it out!

docker pull alpine

If that works you are all set.

Conclusion

So far my experience has been great and pretty snappy. Granted, I am using the latest greatest Apple M1 Chip and this baby purrs.

Other Considerations

I looked at Podman but its Mac implementation is experimental. The Red Hat solution requires using ssh to connect to the remote Podman server. All in all, pretty unelegant.

Happy Containerizing!