You may be on the lookout for a replacement to Docker Desktop at the moment. If you are, you may be wanting to trial the different solutions. You're going to need to know what is involved, and what the different cost models include. This post is going to show you how you can use
docker context to run the different systems in parallel. The two solutions this post will cover are minikube and multipass.
This post assumes the host machine is a Mac. Therefore, we can use brew.sh to install the necessary packages.
brew install hyperkit brew install minikube brew install docker brew install docker-compose
Once this is complete, you can start the
minikube start --driver hyperkit
This will now be running a Virtual Machine we can use for Docker.
Let's use brew.sh again to install the necessary packages.
brew install multipass
Multipass allows us to use cloud-init to define a the environment we can use. This will configure the virtual machine for you. The definition I use is defined below.
users: - name: ubuntu sudo: ALL=(ALL) NOPASSWD:ALL ssh-authorized-keys: - ssh-rsa ..... package_update: true packages: - apt-transport-https - avahi-daemon - ca-certificates - curl - docker - gnupg - lsb-release runcmd: - sudo curl -fsSL https://get.docker.com | sudo bash - sudo systemctl enable docker - sudo systemctl enable -s HUP ssh - sudo groupadd docker - sudo usermod -aG docker ubuntu
It is saved to
$HOME/git/github/benmatselby/dotfiles/common/multipass-docker.yml. You can save this file where you want. Add the contents of your
~/.ssh/id_rsa.pub file to the
ssh-authorized-keys array above. This allows your host machine to
ssh into the virtual machine multipass will create.
Now we want to spin up the multipass environment:
cd $HOME/git/github/benmatselby/dotfiles/common/ multipass launch -c 2 -m 2G -d 10G -n docker-multipass 20.04 --cloud-init multipass-docker.yml
Make sure you
cd into the directory where you saved the
cloud-init script. This command will launch a virtual machine using Ubuntu 20.04, with 10GB of disk space (
-d), 2GB of RAM (
-m), 2 CPUs (
-c), and named
docker-multipass. You can change the values as you see fit. You will need the name of the instance for later.
You may also want to mount some local folders to make life a little easier:
multipass mount /Users docker-multipass multipass mount /Volumes docker-multipass
You can see the information about the VM you created by running:
multipass info docker-multipass Name: docker-multipass State: Running IPv4: 192.168.64.5 172.17.0.1 Release: Ubuntu 20.04.3 LTS Image hash: a83b747df657 (Ubuntu 20.04 LTS) Load: 0.19 0.14 0.05 Disk usage: 1.8G out of 9.5G Memory usage: 232.8M out of 1.9G Mounts: /Volumes => /Volumes UID map: 501:default GID map: 20:default /Users => /Users UID map: 501:default GID map: 20:default
We now have two environments that can be used instead of Docker Desktop:
multipass. The best way to switch between the two systems is to use
docker context. Let's now create a context for multipass, and set it as the default.
docker context create multipass \ --description "Multipass Docker Desktop" \ --docker "host=ssh://firstname.lastname@example.org" docker context use multipass
The name provided in the
multipass launch command, is what becomes the
ubuntu@[multipass name].local value. So if you named your multipass instance "lebowski" you would use
host=ssh://email@example.com as your
--docker context. I used
docker-multipass in the examples above.
The last thing we need to do is
ssh into into the VM so we can accept the authenticity of the host.
You can now leave the VM,
docker run hello-world. This will run the
hello-world container via
You can see what contexts you have by running:
$ docker context ls NAME DESCRIPTION DOCKER ENDPOINT default Current DOCKER_HOST based configuration unix:///var/run/docker.sock desktop-linux unix:///Users/Ben/.docker/run/docker.sock multipass * Multipass Docker Desktop ssh://firstname.lastname@example.org
Let's now add the
minikube context. First, we need some data from minikube to build the context:
minikube -p minikube docker-env export DOCKER_TLS_VERIFY="1" export DOCKER_HOST="tcp://192.168.64.10:2376" export DOCKER_CERT_PATH="/Users/Ben/.minikube/certs" export MINIKUBE_ACTIVE_DOCKERD="minikube"
We need this information for the context connection string. Let's run:
docker context create minikube \ --description "Minikube Docker Desktop" \ --docker "host=tcp://192.168.64.10:2376,cert=/Users/Ben/.minikube/certs/cert.pem,ca=/Users/Ben/.minikube/certs/ca.pem,key=/Users/Ben/.minikube/certs/key.pem"
You can see how we have built up the
--docker string by using the environment variables provided by the
minikube command. Let's now check the contexts we have:
docker context ls NAME DESCRIPTION DOCKER ENDPOINT default Current DOCKER_HOST based configuration unix:///var/run/docker.sock desktop-linux unix:///Users/Ben/.docker/run/docker.soc minikube Minikube Docker Desktop tcp://192.168.64.10:2376 multipass * Multipass Docker Desktop ssh://email@example.com
We can then use
docker context use [name] to switch between the contexts. Let's switch to
minikube and run
docker context use minikube docker run hello-world
You have now run the
hello-world container using both docker contexts.
Docker Desktop is an easy to use system for the Mac. For personal projects, it is great. With the new licensing agreement, businesses may need to review how their engineers run containers during development. This post showed how you can use
docker context to switch between different back ends to help trial alternatives to Docker Desktop.