Podman an alternative to Docker Desktop on MacOS
Getting podman installed and started is super easy.
Just use brew to install it.
> brew install podman
Now since podman uses a VM just like the Docker Client on MacOS we need to initialize that and start it.
> podman machine init
> podman machine start
Now we are set to go.
If you want you can create a symlink so podman can be executed with "docker" command.
> ln -s /usr/local/bin/podman /usr/local/bin/docker
Now most of the commands in podman are the same so try podman images and you will get a list of images.
Else the podman --help command list all the help you need.
To get docker-compose without the docker client for mac. You can install it using the brew command.
> brew install docker-compose
When that is done you now should have the ability to use docker-compose with podman.
On MacOS the podman project does not expose the podman.socket which is similar to docker.socket, by default. So to get docker-compose working one needs to expose the socket.
To get the socket running run the following commands.
First we need to find the port it is exposed on in the VM.
> podman system connection ls
Then we need to take that port and create a forward ssh connection to that.
> ssh -fnNT -L/tmp/podman.sock:/run/user/1000/podman/podman.sock -i ~/.ssh/podman-machine-default ssh://core@localhost:<port to socket> -o StreamLocalBindUnlink=yes
> export DOCKER_HOST='unix:///tmp/podman.sock'
Second, we expose the DOCKER_HOST env variable that is used by docker-compose.
Be aware that if the connection is disconnected one needs to delete/overwrite the /tmp/podman.socket to run the forward command.
Overall findings is that if one only runs single images then it is fairly easy to get going using podman. But if you rely on the compose part to orchestrate the containers in a bigger setup of different images with networking etc. then podman is a lot less easy to get working "out of the box". There is a lot of googling involved and then it still seems that there are a lot of the features that are not too easy to get working. I did have a lot of issues getting the right permissions to mount drives into the images. One of the main features with podman is that it is rootless. Which is great but it means that you need to understand what permissions a container needs before it fully works.
I have tried to use the podman-compose as the goto instead of docker-compose, but I had a hard time even getting it installed, and there were alot of issues where it could not load images from the local repository, so in the end that is why I decided to use docker-compose and not podman-compose. Another thing is that podman-compose is also developed by people not really part of the podman community it seems, or it is not set to be the frist choice by the podman community. So it seems that it is a project that has its own agenda, and is run by a few people and not as many as the podman community.
For now I got it working but I will say that there are many wheels that need tuning and kept updated to have the setup running in a daily development environment.
So if you, like me, just want to use the tools and not need to finetune all the time, it seems a little like there is a way to go before podman takes over the MacOS setup. Next for me is to try to setup everything on my linux laptop and see if this works easier out of the box.