Testcontainers for Go is a Go package that makes it simple to create and clean up container-based dependencies for automated integration/smoke tests. The clean, easy-to-use API enables developers to programmatically define containers that should be run as part of a test and clean up those resources when the test is done.

Here's an example of a test that spins up an NGINX container validates that it returns 200 for the status code:

package main

import (
	"context"
	"fmt"
	"net/http"
	"testing"

	"github.com/testcontainers/testcontainers-go"
	"github.com/testcontainers/testcontainers-go/wait"
)

type nginxContainer struct {
	testcontainers.Container
	URI string
}

func setupNginx(ctx context.Context) (*nginxContainer, error) {
	req := testcontainers.ContainerRequest{
		Image:        "nginx",
		ExposedPorts: []string{"80/tcp"},
		WaitingFor:   wait.ForHTTP("/"),
	}
	container, err := testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
		ContainerRequest: req,
		Started:          true,
	})
	if err != nil {
		return nil, err
	}

	ip, err := container.Host(ctx)
	if err != nil {
		return nil, err
	}

	mappedPort, err := container.MappedPort(ctx, "80")
	if err != nil {
		return nil, err
	}

	uri := fmt.Sprintf("http://%s:%s", ip, mappedPort.Port())

	return &nginxContainer{Container: container, URI: uri}, nil
}

func TestIntegrationNginxLatestReturn(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping integration test")
	}

	ctx := context.Background()

	nginxC, err := setupNginx(ctx)
	if err != nil {
		t.Fatal(err)
	}

	// Clean up the container after the test is complete
	defer func() {
		if err := nginxC.terminate(ctx); err != nil {
			t.Fatalf("failed to terminate container: %w", err)
		}
	}()

	resp, err := http.Get(nginxC.URI)
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("Expected status code %d. Got %d.", http.StatusOK, resp.StatusCode)
	}
}

Cleaning up your environment after test completion should be accomplished by deferring the container termination, e.g defer nginxC.Terminate(ctx). Reaper (Ryuk) is also enabled by default to help clean up.

Documentation

More information about Testcontainers for Go can be found in ./docs, which is rendered at golang.testcontainers.org.