podman-compose/docs/Extensions.md

Podman specific extensions to the docker-compose format

Podman-compose supports the following extension to the docker-compose format. These extensions are generally specified under fields with "x-podman" prefix in the compose file.

Container management

The following extension keys are available under container configuration:

• x-podman.uidmap - Run the container in a new user namespace using the supplied UID mapping.

• x-podman.gidmap - Run the container in a new user namespace using the supplied GID mapping.

• x-podman.rootfs - Run the container without requiring any image management; the rootfs of the container is assumed to be managed externally.

For example, the following docker-compose.yml allows running a podman container with externally managed rootfs.

version: "3"
services:
    my_service:
        command: ["/bin/busybox"]
        x-podman.rootfs: "/path/to/rootfs"

For explanations of these extensions, please refer to the Podman Documentation.

Per-network MAC-addresses

Generic docker-compose files support specification of the MAC address on the container level. If the container has multiple network interfaces, the specified MAC address is applied to the first specified network.

Podman-compose in addition supports the specification of MAC addresses on a per-network basis. This is done by adding a x-podman.mac_address key to the network configuration in the container. The value of the x-podman.mac_address key is the MAC address to be used for the network interface.

Specifying a MAC address for the container and for individual networks at the same time is not supported.

Example:

---
version: "3"

networks:
  net0:
    driver: "bridge"
    ipam:
      config:
        - subnet: "192.168.0.0/24"
  net1:
    driver: "bridge"
    ipam:
      config:
        - subnet: "192.168.1.0/24"

services:
  webserver
    image: "busybox"
    command: ["/bin/busybox", "httpd", "-f", "-h", "/etc", "-p", "8001"]
    networks:
      net0:
        ipv4_address: "192.168.0.10"
        x-podman.mac_address: "02:aa:aa:aa:aa:aa"
      net1:
        ipv4_address: "192.168.1.10"
        x-podman.mac_address: "02:bb:bb:bb:bb:bb"

Podman-specific network modes

Generic docker-compose supports the following values for network-mode for a container:

• bridge
• host
• none
• service
• container

In addition, podman-compose supports the following podman-specific values for network-mode:

• slirp4netns[:<options>,...]
• ns:<options>
• pasta[:<options>,...]
• private

The options to the network modes are passed to the --network option of the podman create command as-is.