Test your Go code against ephemeral elastic search, postgres, nqs, mysql, mongodb, ... docker images on all OS using dockertest!
Latest commit 7bf7a60 Jan 8, 2017 @arekkas arekkas committed on GitHub docs: add examples - closes #73 (#74)



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Use Docker to run your Go language integration tests against third party services on Microsoft Windows, Mac OSX and Linux!

Table of Contents

Why should I use Dockertest?

When developing applications, it is often necessary to use services that talk to a database system. Unit Testing these services can be cumbersome because mocking database/DBAL is strenuous. Making slight changes to the schema implies rewriting at least some, if not all of the mocks. The same goes for API changes in the DBAL. To avoid this, it is smarter to test these specific services against a real database that is destroyed after testing. Docker is the perfect system for running unit tests as you can spin up containers in a few seconds and kill them when the test completes. The Dockertest library provides easy to use commands for spinning up Docker containers and using them for your tests.

Installing and using Dockertest

Using Dockertest is straightforward and simple. Check the releases tab for available releases.

To install dockertest, run

go get gopkg.in/ory-am/dockertest.v3

Using Dockertest

package dockertest_test

import (
    _ "github.com/go-sql-driver/mysql"

var db *sql.DB

func TestMain(m *testing.M) {
    // uses a sensible default on windows (tcp/http) and linux/osx (socket)
    pool, err := dockertest.NewPool("")
    if err != nil {
        log.Fatalf("Could not connect to docker: %s", err)

    // pulls an image, creates a container based on it and runs it
    resource, err := pool.Run("mysql", "5.7", []string{"MYSQL_ROOT_PASSWORD=secret"})
    if err != nil {
        log.Fatalf("Could not start resource: %s", err)

    // exponential backoff-retry, because the application in the container might not be ready to accept connections yet
    if err := pool.Retry(func() error {
        var err error
        db, err = sql.Open("mysql", fmt.Sprintf("root:secret@(localhost:%s)/mysql", resource.GetPort("3306/tcp")))
        if err != nil {
            return err
        return db.Ping()
    }); err != nil {
        log.Fatalf("Could not connect to docker: %s", err)

    code := m.Run()

    // You can't defer this because os.Exit doesn't care for defer
    if err := pool.Purge(resource); err != nil {
        log.Fatalf("Could not purge resource: %s", err)


func TestSomething(t *testing.T) {
    // db.Query()


We provide code examples for well known services in the examples directory, check them out!

Setting up Travis-CI

You can run the Docker integration on Travis easily:

# Sudo is required for docker
sudo: required

# Enable docker
  - docker

Troubleshoot & FAQ

Out of disk space

Try cleaning up the images with docker-cleanup-volumes.

Removing old containers

Sometimes container clean up fails. Check out this stackoverflow question on how to fix this.