Build from Dockerfile

Testcontainers for Go gives you the ability to build an image and run a container from a Dockerfile.

You can do so by specifying a Context (the filepath to the build context on your local filesystem) and optionally a Dockerfile (defaults to "Dockerfile") like so:

Building From a Dockerfile including Repository and Tag

FromDockerfile: FromDockerfile{
    Context:    "testdata",
    Dockerfile: "echo.Dockerfile",
    Repo:       "test-repo",
    Tag:        "test-tag",
},

As you can see, you can also specify the Repo and Tag optional fields to use for the image. If not passed, the image will be built with a random name and tag.

If your Dockerfile expects build args:

FROM alpine

ARG FOO

You can specify them like:

Building From a Dockerfile including build arguments

ba := "build args value"

req := ContainerRequest{
    FromDockerfile: FromDockerfile{
        Context:    filepath.Join(".", "testdata"),
        Dockerfile: "args.Dockerfile",
        BuildArgs: map[string]*string{
            "FOO": &ba,
        },
    },
    ExposedPorts: []string{"8080/tcp"},
    WaitingFor:   wait.ForLog("ready"),
}

Dynamic Build Context

If you would like to send a build context that you created in code (maybe you have a dynamic Dockerfile), you can send the build context as an io.Reader since the Docker Daemon accepts it as a tar file, you can use the tar package to create your context.

To do this you would use the ContextArchive attribute in the FromDockerfile struct.

var buf bytes.Buffer
tarWriter := tar.NewWriter(&buf)
// ... add some files
if err := tarWriter.Close(); err != nil {
    // do something with err
}
reader := bytes.NewReader(buf.Bytes())
fromDockerfile := testcontainers.FromDockerfile{
    ContextArchive: reader,
}

Please Note if you specify a ContextArchive this will cause Testcontainers for Go to ignore the path passed in to Context.

Images requiring auth

If you are building a local Docker image that is fetched from a Docker image in a registry requiring authentication (e.g., assuming you are fetching from a custom registry such as myregistry.com), Testcontainers for Go will automatically discover the credentials for the given Docker image from the Docker config, as described here.

req := ContainerRequest{
    FromDockerfile: testcontainers.FromDockerfile{
        Context: "/path/to/build/context",
        Dockerfile: "CustomDockerfile",
    },
}