DinD (Docker in Docker)¶

Introduction¶

The Testcontainers module for DinD (Docker in Docker).

Adding this module to your project dependencies¶

Please run the following command to add the DinD module to your Go dependencies:

go get github.com/testcontainers/testcontainers-go/modules/dind

Usage example¶

Creating a DinD container

ctx := context.Background()

dindContainer, err := dind.Run(ctx, "docker:28.0.1-dind")
defer func() {
    if err := testcontainers.TerminateContainer(dindContainer); err != nil {
        log.Printf("failed to terminate container: %s", err)
    }
}()
if err != nil {
    log.Printf("failed to start container: %s", err)
    return
}

Module Reference¶

Run function¶

Since v0.36.0

The DinD module exposes one entrypoint function to create the DinD container, and this function receives three parameters:

func Run(ctx context.Context, img string, opts ...testcontainers.ContainerCustomizer) (*Container, error)

context.Context, the Go context.
string, the Docker image to use.
testcontainers.ContainerCustomizer, a variadic argument for passing options.

Image¶

If you need to set a different DinD Docker image, you can set a valid Docker image as the second argument in the Run function. E.g. Run(context.Background(), "docker:28.0.1-dind").

Container Options¶

When starting the DinD container, you can pass options in a variadic way to configure it.

The following options are exposed by the testcontainers package.

Basic Options¶

WithExposedPorts Since v0.37.0
WithEnv Since v0.29.0
WithWaitStrategy Since v0.20.0
WithAdditionalWaitStrategy Since v0.38.0
WithWaitStrategyAndDeadline Since v0.20.0
WithAdditionalWaitStrategyAndDeadline Since v0.38.0
WithEntrypoint Since v0.37.0
WithEntrypointArgs Since v0.37.0
WithCmd Since v0.37.0
WithCmdArgs Since v0.37.0
WithLabels Since v0.37.0

Lifecycle Options¶

WithLifecycleHooks Since v0.38.0
WithAdditionalLifecycleHooks Since v0.38.0
WithStartupCommand Since v0.25.0
WithAfterReadyCommand Since v0.28.0

Files & Mounts Options¶

Build Options¶

WithDockerfile Since v0.37.0

Logging Options¶

Image Options¶

Networking Options¶

Advanced Options¶

WithHostPortAccess Since v0.31.0
WithConfigModifier Since v0.20.0
WithHostConfigModifier Since v0.20.0
WithEndpointSettingsModifier Since v0.20.0
CustomizeRequest Since v0.20.0
WithName Since v0.38.0
WithNoStart Since v0.38.0
WithProvider Not available until the next release main

Experimental Options¶

WithReuseByName Since v0.37.0

Container Methods¶

The DinD container exposes the following methods:

Host¶

Since v0.36.0

The Host method returns the DinD URL, to be used for connecting to the Docker API using a Docker client. It'll be returned in the format of string.

HostGet a Docker client

host, err := dindContainer.Host(ctx)
if err != nil {
    log.Printf("failed to get docker host: %s", err)
    return
}

cli, err := client.NewClientWithOpts(client.WithHost(host), client.WithAPIVersionNegotiation())
if err != nil {
    log.Printf("failed to create docker client: %s", err)
    return
}

LoadImage¶

Since v0.36.0

The LoadImage method loads an image into the docker in docker daemon.

This is useful for testing images generated locally without having to push them to a public docker registry.

The images must be already present in the node running the test. DockerProvider offers a method for pulling images, which can be used from the test code to ensure the image is present locally before loading them to the daemon.