Testcontainers-scala

Scala wrapper for testcontainers-java that allows using docker containers for functional/integration/~~unit~~ testing.

TestContainers is a Java 8 library that supports JUnit tests, providing lightweight, throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.

Testcontainers-scala in action: http://dimafeng.com/2016/08/01/testcontainers-selenium/

Slack

Slack channel

Invite link for slack

Setup

For scalatest users:

libraryDependencies += "com.dimafeng" %% "testcontainers-scala-scalatest" % testcontainersScalaVersion % "test"

Requirements

JDK >= 1.8
See 'Compatibility' section

Quick Start

First of all, let's add scalatest and MySQL testcontainers modules in the build.sbt file to play with:

libraryDependencies ++= Seq(
  "com.dimafeng" %% "testcontainers-scala-scalatest" % testcontainersScalaVersion % "test",
  "com.dimafeng" %% "testcontainers-scala-mysql" % testcontainersScalaVersion % "test",
)

There are two ScalaTest aware traits:

ForEachTestContainer starts a new container(s) before each test case and then stops and removes it.
ForAllTestContainer starts and stops a container only once for all test cases within the spec.

To start using it, you just need to extend one of those traits and override a container val as follows:

import com.dimafeng.testcontainers.{ForAllTestContainer, MySQLContainer}

class MysqlSpec extends FlatSpec with ForAllTestContainer {

  override val container = MySQLContainer()

  it should "do something" in {
    Class.forName(container.driverClassName)
    val connection = DriverManager.getConnection(container.jdbcUrl, container.username, container.password)
    ...
  }
}

This spec has a clean mysql database instance for each of its test cases.

import org.testcontainers.containers.MySQLContainer

class MysqlSpec extends FlatSpec with ForAllTestContainer {

    override val container = MySQLContainer()

    it should "do something" in {
      ...
    }

    it should "do something 2" in {
      ...
    }
}

This spec starts one container and both tests share the container's state.

Modules

Testcontainers-scala is modular. All modules has the same version. To depend on some module put this into your build.sbt file:

libraryDependencies += "com.dimafeng" %% moduleName % testcontainersScalaVersion % "test"

Here is the full list of the currently available modules:

testcontainers-scala-core — core module. It contains some basic building blocks of the library and no integration with any test frameworks. You probably will not use it directly, because all other modules depend on it.
testcontainers-scala-scalatest — Scalatest integration module.
testcontainers-scala-scalatest-selenium — module to use the Selenium container with the Scalatest.
testcontainers-scala-mysql — module with the MySQL container.
testcontainers-scala-postgres — module with the PostgreSQL container.
testcontainers-scala-cassandra — module with the Cassandra container.
testcontainers-scala-kafka — module with the Kafka container.
testcontainers-scala-vault — module with the Vault container.

Container types

Generic Container

The most flexible but less convenient container type is GenericContainer. This container allows to launch any docker image with custom configuration.

class GenericContainerSpec extends FlatSpec with ForAllTestContainer {
  override val container = GenericContainer("nginx:latest",
    exposedPorts = Seq(80),
    waitStrategy = Wait.forHttp("/")
  )

  "GenericContainer" should "start nginx and expose 80 port" in {
    assert(Source.fromInputStream(
      new URL(s"http://${container.containerIpAddress}:${container.mappedPort(80)}/").openConnection().getInputStream
    ).mkString.contains("If you see this page, the nginx web server is successfully installed"))
  }
}

Docker Compose

class ComposeSpec extends FlatSpec with ForAllTestContainer {
  override val container = DockerComposeContainer(new File("src/test/resources/docker-compose.yml"), exposedServices = Seq(ExposedService("redis_1", 6379)))

  "DockerComposeContainer" should "retrieve non-0 port for any of services" in {
    assert(container.getServicePort("redis_1", 6379) > 0)
  }
}

Selenium

Before you can use this type of containers, you need to add the following dependencies to your project:

"com.dimafeng" %% "testcontainers-scala-scalatest-selenium" % testcontainersScalaVersion % "test"

Now you can write a test in this way:

class SeleniumSpec extends FlatSpec with SeleniumTestContainerSuite with WebBrowser {
  override def desiredCapabilities = DesiredCapabilities.chrome()

  "Browser" should "show google" in {
      go to "http://google.com"
  }
}

In this case, you'll obtain a clean instance of browser (firefox/chrome) within container to which a test will connect via remote-driver. See Webdriver Containers for more details.

Mysql

Requires you to add this dependency:

"com.dimafeng" %% "testcontainers-scala-mysql" % testcontainersScalaVersion % "test"

class MysqlSpec extends FlatSpec with ForAllTestContainer {

  override val container = MySQLContainer()

  "Mysql container" should "be started" in {
    Class.forName(container.driverClassName)
    val connection = DriverManager.getConnection(container.jdbcUrl, container.username, container.password)
      ...
  }
}

The container can also be customized using the constructor parameters, this snippet will initialize a docker container from a specific docker image, with a specific schema name and specific username/password

class MysqlSpec extends FlatSpec with ForAllTestContainer {

  override val container = MySQLContainer(mysqlImageVersion = "mysql:5.7.18",
                                          databaseName = "testcontainer-scala",
                                          username = "scala",
                                          password = "scala")

  "Mysql container" should "be started" in {
    Class.forName(container.driverClassName)
    val connection = DriverManager.getConnection(container.jdbcUrl, container.username, container.password)
      ...
  }
}

PostgreSQL

Requires you to add this dependency:

"com.dimafeng" %% "testcontainers-scala-postgresql" % testcontainersScalaVersion % "test"

class PostgresqlSpec extends FlatSpec with ForAllTestContainer  {

  override val container = PostgreSQLContainer()

  "PostgreSQL container" should "be started" in {
    Class.forName(container.driverClassName)
    val connection = DriverManager.getConnection(container.jdbcUrl, container.username, container.password)
      ...
  }
}

Multiple Containers

If you need to test more than one container in your test, you could use MultipleContainers for that. Just define your containers and pass them to the MultipleContainers constructor:

val mySqlContainer = MySQLContainer()
val genericContainer = GenericContainer(...)

override val container = MultipleContainers(mySqlContainer, genericContainer)

Dependent containers

If configuration of one container depends on runtime state of another one, you should define your containers as lazy:

lazy val container1 = Container1()
lazy val container2 = Container2(container1.port)

override val container = MultipleContainers(container1, container2)

Fixed Host Port Containers

This container will allow you to map container ports to statically defined ports on the docker host.

...
val container = FixedHostPortGenericContainer("nginx:latest",
    waitStrategy = Wait.forHttp("/"),
    exposedHostPort = 8090,
    exposedContainerPort = 80
  )

Custom configuration of inner containers

All container types have constructor methods with most popular parameters. In case you're missing some custom option from testcontainers-java, there is a method that provides an elegant way to tune the nested container. It's not recommended to access inner container directly.

override val container = MySQLContainer().configure { c =>
    c.withNetwork(...)
    c.withStartupAttempts(...)
  }

Start/Stop hooks

If you want to execute your code after container start or before container stop you can override afterStart() and beforeStop() methods.

class MysqlSpec extends FlatSpec with ForAllTestContainer {

  ...

  override def beforeStop(): Unit = {
    // your code
  }

  override def afterStart(): Unit = {
    // your code
  }
}

New API

Starting from 0.34.0 version testcontainers-scala provides the new API. The main motivation points are in the pull request.

This API is experimental and may change!

`Container` and `ContainerDef`

Docker containers are represented through the two different entities:

ContainerDef — it's container definition. ContainerDef describes, how to build a container. You can think about it like about a container constructor, or dockerfile description. Usually, ContainerDef receives some parameters. ContainerDef has a start() method. It returns a started Container.
Container — it's a started container. You can interact with it through its methods. For example, in the case of MySQLContainer you can get it's JDBC URL with jdbcUrl method. Container is the main entity for using inside tests.

Scalatest usage

You can use one of the four traits:

TestContainerForAll — will start a single container before all tests and stop after all tests.
TestContainerForEach — will start a single container before each test and stop after each test.
TestContainersForAll — will start multiple containers before all tests and stop after all tests.
TestContainersForEach — will start multiple containers before each test and stop after each test.

Single container in tests

If you want to use a single container in your test:

class MysqlSpec extends FlatSpec with TestContainerForAll {

  // You need to override `containerDef` with needed container definition
  override val containerDef = MySQLContainer.Def()

  // To use containers in tests you need to use `withContainers` function
  it should "test" in withContainers { mysqlContainer =>
    // Inside your test body you can do with your container whatever you want to
    assert(mysqlContainer.jdbcUrl.nonEmpty)
  }
}

Usage of TestContainerForEach is not different from the example above.

Multiple containers in tests

If you want to use multiple containers in your test:

class ExampleSpec extends FlatSpec with TestContainersForAll {

  // First of all, you need to declare, which containers you want to use
  override type Containers = MySQLContainer and PostgreSQLContainer

  // After that, you need to describe, how you want to start them,
  // In this method you can use any intermediate logic.
  // You can pass parameters between containers, for example.
  override def startContainers(): Containers = {
    val container1 = MySQLContainer.Def().start()
    val container2 = PostgreSQLContainer.Def().start()
    container1 and container2
  }
  
  // `withContainers` function supports multiple containers:
  it should "test" in withContainers { case mysqlContainer and pgContainer =>
    // Inside your test body you can do with your containers whatever you want to
    assert(mysqlContainer.jdbcUrl.nonEmpty && pgContainer.jdbcUrl.nonEmpty)
  }
  
}

Usage of TestContainersForEach is not different from the example above.

`GenericContainer` usage

To create a custom container, which is not built-in in the library, you need to use GenericContainer.

For example, you want to create a custom nginx container:

class NginxContainer(port: Int, underlying: GenericContainer) extends GenericContainer(underlying) {
  // you can add any methods or fields inside your container's body
  def rootUrl: String = s"http://$containerIpAddress:${mappedPort(port)}/"
}
object NginxContainer {

  // In the container definition you need to describe, how your container will be constructed:
  case class Def(port: Int) extends GenericContainer.Def[NginxContainer](
    new NginxContainer(port, GenericContainer(
      dockerImage = "nginx:latest",
      exposedPorts = Seq(port),
      waitStrategy = Wait.forHttp("/")
    ))
  )
}

Migration from the classic API

If you have custom containers created with the GenericContainer, add ContainerDef in the companion like this:

object MyCustomContainer {
  case class Def(/*constructor params here*/) extends GenericContainer.Def[MyCustomContainer](
    new MyCustomContainer(/*constructor params here*/)
  )
}

If you are using ForEachTestContainer:
1. If your test contains only one container, replace ForEachTestContainer with TestContainerForEach
2. If your test contains multiple containers, replace ForEachTestContainer with TestContainersForEach
If you are using ForAllTestContainer:
1. If your test contains only one container, replace ForAllTestContainer with TestContainerForAll
2. If your test contains multiple containers, replace ForAllTestContainer with TestContainersForAll
Fix all compilation errors using compiler messages and examples above.

If you have any questions or difficulties feel free to ask it in our slack channel.

Release notes

0.34.1
- New API improvements:
  - Changed signature of def withContainers(runTest: Containers => Unit): Unit to def withContainers[A](runTest: Containers => A): A
  - Renamed afterStart to afterContainersStart and added a containers: Containers argument to it.
  - Renamed beforeStop to beforeContainersStop and added a containers: Containers argument to it.
0.34.0
- Added new, experimental API and DSL. The main motivation points are in the pull request. Old API remains the same, so all your old code will continue to work.
  We will wait for the user's feedback about the new API. If it will be positive, eventually this API may replace the current API. You can find more information about the new API above.
- The library is split into multiple modules. Every built-in container now has a separate module with all needed transitive dependencies, so you will not have to add them manually. More details are above, in the dedicated paragraph. Old module testcontainers-scala is still provided but will be eventually dropped in future. To migrate to the new modules remove testcontainers-scala dependency and add only needed dependencies from the modules list in the docs.
0.33.0
- TestContainers 1.12.1 -> 1.12.2
0.32.0
- TestContainers -> 1.12.1
- SBT -> 1.3.0
0.31.0
- Additional config options for PostgreSQL #70
0.30.0
- TestContainers -> 1.12.0
- Scala -> 2.12.9
0.29.0
- TestContainers 1.11.2 -> 1.11.4
0.28.0
- VaultContainer
0.27.0
- New TestLifecycleAware trait introduced. You can use it when you want to do something with the container before or after the test.
- Container now implements Startable interface with start and stop methods.
- Old container's lifecycle methods finished, succeeded, starting, failed are deprecated. Use start, stop, and TestLifecycleAware methods instead.
- Added KafkaContainer
- Added CassandraContainer
0.26.0
- TestContainers 1.11.2 -> 1.11.3
- Scala 2.13.0
0.25.0
- TestContainers 1.11.1 -> 1.11.2
0.24.0
- TestContainers 1.10.6 -> 1.11.1
- Scala 2.13.0-M5
0.23.0
- TestContainers 1.10.1 -> 1.10.6
0.22.0
- TestContainers 1.9.1 -> 1.10.1
0.21.0
- TestContainers 1.8.3 -> 1.9.1
0.20.0
- TestContainers 1.8.0 -> 1.8.3
0.19.0
- TestContainers 1.7.3 -> 1.8.0
- (#24) DockerComposeContainer enhancements
- Added Dockerfile support to GenericContainer
0.18.0
- TestContainers 1.7.1 -> 1.7.3
0.17.0
- Testcontainers 1.6.0 -> 1.7.1
- Removed shapeless dependency
- Added implicit conversion to LazyContainer. This gives you a possibility to not wrap your containers into the LazyContainer manually.
- MultipleContainers.apply now receives LazyContainer[_]* type. Together with the previous point, it makes usage experience of MultipleContainers more smooth.
- Added multiple missing reflecting methods to all containers
- Added configure method. See this for more details
0.16.0
- FixedHostPortGenericContainer added
0.15.0
- Additional configuration parameters for MySQLContainer
- Improvements to MultipleContainers - container lazy creation for dependent containers
0.14.0
- TestContainers 1.5.1 -> 1.6.0
0.13.0
- TestContainers 1.4.3 -> 1.5.1
- Scala 2.10 support
0.12.0
- Improvement: afterStart hook now handles exceptions correctly
0.11.0
- Improvement: containers don't start in ForAllTestContainer if all tests are ignored
0.10.0
- TestContainers 1.4.2 -> 1.4.3
- Fix of #8
0.8.0
- PostgreSQL container
0.7.0
- TestContainers 1.2.1 -> 1.4.2
0.6.0
- TestContainers 1.2.0 -> 1.2.1
- Fix of the afterStart hook
0.5.0
- TestContainers 1.1.8 -> 1.2.0
0.4.1
- TestContainers 1.1.7 -> 1.1.8
0.4.0
- TestContainers 1.1.5 -> 1.1.7
- Scala cross-building (2.11.* + 2.12.*)
0.3.0
- TestContainers 1.1.0 -> 1.1.5
- Start/Stop hooks
0.2.0
- TestContainers 1.0.5 -> 1.1.0
- Code refactoring
- Scala wrappers for major container types

Publishing

$ sbt clean release

chameleon82/testcontainers-scala