Docker Desktop — Moving away

Docker is changing its licensing model and Docker Desktop will require a subscription starting 31st Jan 2022, more details here.

Docker Engine provides a runtime for Containers, other popular container runtimes are:

• Containerd
• CRI-O
• Mirantis Container Runtime
• runc
• crun
• runv

etc…

All container runtimes follow certain set of standards set by OCI initiative.

Next, we need a CLI which can spawn and manage containers using any of OCI Compliant runtimes, here we’re exploring below 2 options:

• nerdctl
• podman

Installing nerdctl on MacOs:

brew install lima
limactl start

Few basic commands:

# see running containers
lima nerdctl ps
# run a new container
lima nerdctl run nginx
# display details of local images
lima nerdctl images
# building a new image
nerdctl build -t foo /some-dockerfile-directory

Commands are similar to docker commands, thus you can create an alias and continue to use same old docker commands.

alias docker="lima nerdctl"

Note: limactl start will create a ubuntu (default) virtual machine

You can run commands inside this machine by prefixing commands with lima such as:

lima uname -a

when you’re done using containers, do limactl stop to stop the virtual machine.

and limactl remove default to remove the image.

Installing podman on MacOs:

brew install podman
podman machine init
podman machine start

Few basic commands:

# see running containers
podman ps
# run a new container
podman run nginx
# display details of images
podman images
# building a new image
podman build -t foo /some-dockerfile-directory

As commands are similar to docker you can create an alias:

alias docker="podman"

and keep using same old commands.

Click here for more details on podman

Note: podman machine init download a fedora-coreos virtual machine image

podman machine start will create a virtual machine using quemu virtualisation on MacOs.

To cleanup afterwards, do:

podman machine stop
podman machine rm

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