Podman Compose

An implementation of Compose Spec with Podman backend. This project focus on:

• rootless
• daemon-less process model, we directly execute podman, no running daemon.

This project only depend on:

• podman
• podman dnsname plugin: It is usually found in the podman-plugins or podman-dnsname distro packages, those packages are not pulled by default and you need to install them. This allow containers be able to resolve each other if they are on the same CNI network.
• Python3
• PyYAML
• python-dotenv

And it's formed as a single python file script that you can drop into your PATH and run.

References:

• spec.md
• docker-compose compose-file-v3
• docker-compose compose-file-v2

Alternatives

As in this article you can setup a podman.socket and use unmodified docker-compose that talks to that socket but in this case you lose the process-model (ex. docker-compose build will send a possibly large context tarball to the daemon)

For production-like single-machine containerized environment consider

• k3s | k3s github
• MiniKube

For the real thing (multi-node clusters) check any production OpenShift/Kubernetes distribution like OKD.

Versions

If you have legacy version of podman (before 3.1.0) you might need to stick with legacy podman-compose 0.1.x branch. The legacy branch 0.1.x uses mappings and workarounds to compensate for rootless limitations.

Modern podman versions (>=3.4) do not have those limitations and thus you can use latest and stable 1.x branch.

If you are upgrading from podman-compose version 0.1.x then we no longer have global option -t to set mapping type like hostnet. If you desire that behavior pass it the standard way like network_mode: host in the YAML.

Installation

Install latest stable version from PyPI:

pip3 install podman-compose

pass --user to install inside regular user home without being root.

Or latest development version from GitHub:

pip3 install https://github.com/containers/podman-compose/archive/devel.tar.gz

or

curl -o /usr/local/bin/podman-compose https://raw.githubusercontent.com/containers/podman-compose/devel/podman_compose.py
chmod +x /usr/local/bin/podman-compose

or inside your home

curl -o ~/.local/bin/podman-compose https://raw.githubusercontent.com/containers/podman-compose/devel/podman_compose.py
chmod +x ~/.local/bin/podman-compose

or install from Fedora (starting from f31) repositories:

sudo dnf install podman-compose

Basic Usage

We have included fully functional sample stacks inside examples/ directory.

A quick example would be

cd examples/busybox
podman-compose --help
podman-compose up --help
podman-compose up

A more rich example can be found in examples/awx3 which have

• A Postgres Database
• RabbitMQ server
• MemCached server
• a django web server
• a django tasks

When testing the AWX3 example, if you got errors just wait for db migrations to end. There is also AWX 17.1.0

Tests

Inside tests/ directory we have many useless docker-compose stacks that are meant to test as much cases as we can to make sure we are compatible

Unit tests with pytest

run a pytest with following command

python -m pytest pytests