Using Podman instead of Docker

Testcontainers for Go supports the use of Podman (rootless or rootful) instead of Docker. In most scenarios no special setup is required. Testcontainers for Go will automatically discover the socket based on the DOCKER_HOST or the TC_HOST environment variables. Alternatively you can configure the host with a .testcontainers.properties file. The discovered Docker host is also taken into account when starting a reaper container.

There's currently only one special case where additional configuration is necessary: complex container network scenarios.

By default Testcontainers for Go takes advantage of the default network settings both Docker and Podman are applying to newly created containers. It only intervenes in scenarios where a ContainerRequest specifies networks and does not include the default network of the current container provider. Unfortunately the default network for Docker is called bridge where the default network in Podman is called podman. It is not even possible to create a network called bridge with Podman as Podman does not allow creating a network with the same name as an already existing network mode.

In such scenarios it is possible to explicitly make use of the ProviderPodman like so:

package some_test

import (
    "testing"
    tc "github.com/testcontainers/testcontainers-go"
)

func TestSomething(t *testing.T) {
    req := tc.GenericContainerRequest{
        ProviderType: tc.ProviderPodman,
        ContainerRequest: tc.ContainerRequest{
            Image: "docker.io/nginx:alpine"
        },
    }

    // ...
}

The ProviderPodman configures the DockerProvider with the correct default network for Podman to ensure also complex network scenarios are working as with Docker.