podman-dind-like

A Docker-in-Docker like container using Podman

Description

This takes the quay.io/podman/stable image and extends it with some enhancements to make it more docker like and able to use docker as a command as well as includes docker-compose.

Notes on Github Actions

This job runs on a self-hosted Github Actions agent and publishes to Github's container registry ghcr.io as a 'public' image and can be downloaded via a simple docker command or other means as you see fit.

Note: The build-push action doesn't work with 'podman' (commented out in the pipeline) as it tightly coupled with 'buildx' which is only supported with native docker.

docker pull ghcr.io/jamesjonesconsulting/podman-dind-like:latest

Why is there a second container in the matrix?

The matrix defined in the pipeline pushes the public container (as described above), but also publishes a private container to my instance of Nexus Repository for my home lab usage. Having this container 'local' to my home lab saves bandwidth and accellerates my use cases. In addition, it's an example of the usage of the 'matrix' feature in a repository I have public so others may benefit from seeing the pattern in use.

Notes on GitLab

This job also runs on a self-hosted gitlab agent with the following in the /etc/gitlab-runner/config.toml file so this is also compatible with other self-hosted agents for other CI/CD self-hosted agents.

  [runners.docker]
    host = "unix:///run/podman/podman.sock"
    tls_verify = false
    image = "quay.io/podman/stable"
    privileged = true
    network_mode = "host"

Setting up Podman socket on build machines for use with muliple flavors of CI/CD agents

First, install podman.socket

sudo dnf install -y podman.socket; sudo systemctl enable --now podman.socket

Create an systemd overlay to use the docker group on the socket file (note: you'll have to create this group yourself separately).

aka: Create a file as /etc/systemd/system/podman.socket.d/overlay.conf containing:

[Socket]
SocketMode=0660
SocketUser=root
SocketGroup=docker

Created a tmpfiles.d entry as /etc/tmpfiles.d/podman.conf file containing (ensuring that folder will retain the correct permissions after reboots)

d /run/podman 0770 root docker

Note: This ensures that the group docker has permissions to use this socket.

Finally, add the agent users to the docker group (whichever agent you are using).

Run sudo systemctl reload-daemon and reboot (quickest way).