Using Docker Compose¶

Similar to generic containers support, it's also possible to run a bespoke set of services specified in a docker-compose.yml file.

This is intended to be useful on projects where Docker Compose is already used in dev or other environments to define services that an application may be dependent upon.

Using `docker-compose` directly¶

Warning

The minimal version of Go required to use this module is 1.20.

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

Warning

Given the version includes the Compose dependency, and the Docker folks added a replace directive in their go.mod, we were forced to add it as well. As a result, users of Testcontainers for Go need to add the following replace directive to their go.mod files.

replace (
    github.com/cucumber/godog => github.com/laurazard/godog v0.0.0-20220922095256-4c4b17abdae7
)

Because docker-compose v2 is implemented in Go it's possible for Testcontainers for Go to use github.com/docker/compose directly and skip any process execution/docker-compose-in-a-container scenario. The ComposeStack API exposes this variant of using docker-compose in an easy way.

Basic examples¶

Use the convenience NewDockerCompose(...) constructor which creates a random identifier and takes a variable number of stack files:

package example_test

import (
    "context"
    "testing"

    "github.com/stretchr/testify/assert"
    tc "github.com/testcontainers/testcontainers-go/modules/compose"
)

func TestSomething(t *testing.T) {
    compose, err := tc.NewDockerCompose("testdata/docker-compose.yml")
    assert.NoError(t, err, "NewDockerComposeAPI()")

    t.Cleanup(func() {
        assert.NoError(t, compose.Down(context.Background(), tc.RemoveOrphans(true), tc.RemoveImagesLocal), "compose.Down()")
    })

    ctx, cancel := context.WithCancel(context.Background())
    t.Cleanup(cancel)

    assert.NoError(t, compose.Up(ctx, tc.Wait(true)), "compose.Up()")

    // do some testing here
}

Use the advanced NewDockerComposeWith(...) constructor allowing you to specify an identifier:

package example_test

import (
    "context"
    "testing"

    "github.com/stretchr/testify/assert"
    tc "github.com/testcontainers/testcontainers-go/modules/compose"
)

func TestSomethingElse(t *testing.T) {
    identifier := tc.StackIdentifier("some_ident")
    compose, err := tc.NewDockerComposeWith(tc.WithStackFiles("./testdata/docker-compose-simple.yml"), identifier)
    assert.NoError(t, err, "NewDockerComposeAPIWith()")

    t.Cleanup(func() {
        assert.NoError(t, compose.Down(context.Background(), tc.RemoveOrphans(true), tc.RemoveImagesLocal), "compose.Down()")
    })

    ctx, cancel := context.WithCancel(context.Background())
    t.Cleanup(cancel)

    assert.NoError(t, compose.Up(ctx, tc.Wait(true)), "compose.Up()")

    // do some testing here
}

Interacting with compose services¶

To interact with service containers after a stack was started it is possible to get an *tc.DockerContainer instance via the ServiceContainer(...) function. The function takes a service name (and a context.Context) and returns either a *tc.DockerContainer or an error. This is different to the previous LocalDockerCompose API where service containers were accessed via their container name e.g. mysql_1 or mysql-1 (depending on the version of docker-compose).

Furthermore, there's the convenience function Serices() to get a list of all services defined by the current project. Note that not all of them need necessarily be correctly started as the information is based on the given compose files.

Wait strategies¶

Just like with regular test containers you can also apply wait strategies to docker-compose services. The ComposeStack.WaitForService(...) function allows you to apply a wait strategy to a service by name. All wait strategies are executed in parallel to both improve startup performance by not blocking too long and to fail early if something's wrong.

Example¶

package example_test

import (
    "context"
    "testing"
    "time"

    "github.com/stretchr/testify/assert"
    tc "github.com/testcontainers/testcontainers-go/modules/compose"
    "github.com/testcontainers/testcontainers-go/wait"
)

func TestSomethingWithWaiting(t *testing.T) {
    identifier := tc.StackIdentifier("some_ident")
    compose, err := tc.NewDockerComposeWith(tc.WithStackFiles("./testdata/docker-compose-simple.yml"), identifier)
    assert.NoError(t, err, "NewDockerComposeAPIWith()")

    t.Cleanup(func() {
        assert.NoError(t, compose.Down(context.Background(), tc.RemoveOrphans(true), tc.RemoveImagesLocal), "compose.Down()")
    })

    ctx, cancel := context.WithCancel(context.Background())
    t.Cleanup(cancel)

    err = compose.
        WaitForService("nginx", wait.NewHTTPStrategy("/").WithPort("80/tcp").WithStartupTimeout(10*time.Second)).
        Up(ctx, tc.Wait(true))

    assert.NoError(t, err, "compose.Up()")

    // do some testing here
}

Compose environment¶

docker-compose supports expansion based on environment variables. The ComposeStack supports this as well in two different variants:

ComposeStack.WithEnv(m map[string]string) ComposeStack to parameterize stacks from your test code
ComposeStack.WithOsEnv() ComposeStack to parameterize tests from the OS environment e.g. in CI environments

Docs¶

Also have a look at ComposeStack docs for further information.

Usage of `docker-compose` binary¶

Node: this API is deprecated and superseded by ComposeStack which takes advantage of docker-compose v2 being implemented in Go as well by directly using the upstream project.

You can override Testcontainers' default behaviour and make it use a docker-compose binary installed on the local machine. This will generally yield an experience that is closer to running docker-compose locally, with the caveat that Docker Compose needs to be present on dev and CI machines.

Examples¶

composeFilePaths := []string {"testdata/docker-compose.yml"}
identifier := strings.ToLower(uuid.New().String())

compose := tc.NewLocalDockerCompose(composeFilePaths, identifier)
execError := compose.
    WithCommand([]string{"up", "-d"}).
    WithEnv(map[string]string {
        "key1": "value1",
        "key2": "value2",
    }).
    Invoke()

err := execError.Error
if err != nil {
    return fmt.Errorf("Could not run compose file: %v - %v", composeFilePaths, err)
}
return nil

Note that the environment variables in the env map will be applied, if possible, to the existing variables declared in the Docker Compose file.

In the following example, we demonstrate how to stop a Docker Compose created project using the convenient Down method.

composeFilePaths := []string{"testdata/docker-compose.yml"}

compose := tc.NewLocalDockerCompose(composeFilePaths, identifierFromExistingRunningCompose)
execError := compose.Down()
err := execError.Error
if err != nil {
    return fmt.Errorf("Could not run compose file: %v - %v", composeFilePaths, err)
}
return nil

Using Docker Compose¶