Docker Desktop から Podman Desktop への移行

Compatibility

Podman Desktop’s Docker compatibility feature lets the Docker CLI and tools that talk to the Docker socket, such as Testcontainers, Maven or Gradle, run against a Podman engine. Compose v2 applications run through the Compose extension, so docker compose up works on Podman.

How the socket is wired depends on the platform:

• macOS: the podman-mac-helper utility links /var/run/docker.sock to the Podman machine’s socket. The Third-Party Docker Tool Compatibility setting that does this is on by default.
• Windows: Podman also listens on the default docker_engine named pipe.
• Linux: point tools at Podman with the DOCKER_HOST variable.

Before you switch

1. Start a Podman machine.
2. Turn on Settings > Preferences > Docker Compatibility. A Docker Compatibility page then appears under Settings.
3. On that page, check the system socket status, pick the Docker CLI context, and use Setup… next to Podman Compose CLI Support if Compose is not installed.
4. Check that docker info --format=json | jq -r .ServerVersion returns the Podman version.
5. Bring over containers you want to keep: export each one with docker export <container> -o <archive>.tar, then run podman import <archive>.tar.
6. Where tools do not find the socket, set DOCKER_HOST: unix:// plus the output of podman machine inspect --format '{{.ConnectionInfo.PodmanSocket.Path}}' on macOS, or of podman info --format '{{.Host.RemoteSocket.Path}}' on Linux, and npipe:// plus the PodmanPipe path on Windows. A docker context create podman --docker "host=..." context works too.

Pitfalls

• An imported container comes back as an image, not a running container. podman import lists it under Images, and you start a new container from it. The guide does not cover volumes, networks or Docker Desktop’s Kubernetes cluster.
• The Third-Party Docker Tool Compatibility setting exists only on macOS. Re-enabling it asks for your machine password and a restart of the Podman machine.
• On Windows, podman compose can fail with Error: socket of machine is not set until DOCKER_HOST is set.
• The guide asks you to keep your Compose file in a working directory such as your home directory.