Dockertest

dockertest allows you to quickly and easily test database interactions by creating and destroying databases within your tests using docker.

It works by controlling the docker daemon running locally with exec.Command. The flow is as follows ->

find a free port on the local machine
launch docker container and bind that port
wait until the container needs to be shutdown

dockertest is inspired by https://divan.github.io/posts/integration_testing/ and https://github.com/ory-am/dockertest - however, it does not add 300k loc of dependencies (guesstimated) to your project. See fsouza/go-dockerclient#599 for more info on this.

Installation

go get -u github.com/fortytw2/dockertest

currently the tests depend on github.com/lib/pq

How good is it?

Currently the manipulation of the docker daemon is somewhat fragile, as it depends on exec.Command and a well placed time.Sleep for shutdown. In an ideal world, this would use the docker api via the docker socket directly, but it currently works well enough for now. Contributions welcome

Usage

Postgres example copied from github.com/fortytw2/hydrocarbon

func TestDBBits(t *testing.T) {
	container, err := dockertest.RunContainer("postgres:alpine", "5432", func(addr string) error {
		db, err := sql.Open("postgres", "postgres://postgres:postgres@"+addr+"?sslmode=disable")
		if err != nil {
			return err
		}

		return db.Ping()
	})
	defer container.Shutdown()
	if err != nil {
		t.Fatalf("could not start postgres, %s", err)
	}

	db, err := sql.Open("postgres", "postgres://postgres:postgres@" + container.Addr + "?sslmode=disable")
	if err != nil {
		t.Fatal(err)
	}

	// run tests on the db, etc
}

It should be trivial to adapt the above bits to work just as well from a TestMain function, if you want to avoid running a new container for each individual test function - subtests also help here.

Docker-machine host

Note that dockertest will give priority to the DOCKER_MACHINE_NAME when looking for your container address and will fallback to localhost if it fails to find it.

License

MIT, see LICENSE

docmerlin / dockertest