JarCastingdockerenv
Dockerenv provides a handle on useful docker containers, typically for running tests against real services as opposed to having to mock.
See docs here
The gist is that we can easily spin up real services (databases, kafka clusters, etc) which we can then connect against.
e.g. Import docker env in your build like this:
libraryDependencies += "com.github.aaronp" %% "dockerenv" % "latest version" % "test"
Then use it like this:
println(step("Let's do some ETL! Starting Mysql...", 0))
dockerenv.mysql().bracket {
println(step("Mysql Started, Starting Kafka", 1))
dockerenv.kafka().bracket {
println(step("Kafka Started, Starting Mongo", 2))
dockerenv.mongo().bracket {
println(step("All up! Killing Mongo...", 3))
}
println(step("Mongo Down, Killing Kafka", 2))
}
println(step("Kafka Down, Killing Mysql", 1))
}
println(step("All done!", 0))
// pretty-prints the message with the current 'docker ps' status
private def step(msg: String, indent: Int): String = {
val status = dockerPS
...
}
def dockerPS: String = "docker ps".!!
The output for which is:
_____________________________________________________________________________________________________________________________
Let's do some ETL! Starting Mysql...
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
________________________________________________________________________________________________________________________________________________________________
Mysql Started, Starting Kafka
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
39d16d02b95c mysql:8.0.18 "docker-entrypoint.s…" 1 second ago Up Less than a second 33060/tcp, 0.0.0.0:7777->3306/tcp dockerenv-mysql
__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Kafka Started, Starting Mongo
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a6e9bea0393c dockerenv-kafka:test "supervisord -n" 1 second ago Up Less than a second 0.0.0.0:2181->2181/tcp, 0.0.0.0:8083->8083/tcp, 0.0.0.0:9080->9080/tcp, 0.0.0.0:9092->9092/tcp, 0.0.0.0:29092->29092/tcp test-kafka
39d16d02b95c mysql:8.0.18 "docker-entrypoint.s…" 2 seconds ago Up 1 second 33060/tcp, 0.0.0.0:7777->3306/tcp dockerenv-mysql
__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
All up! Killing Mongo...
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fef2d8c0662a mongo:4.0 "docker-entrypoint.s…" 1 second ago Up Less than a second 0.0.0.0:9010->27017/tcp dockerenv-mongo
a6e9bea0393c dockerenv-kafka:test "supervisord -n" 2 seconds ago Up 1 second 0.0.0.0:2181->2181/tcp, 0.0.0.0:8083->8083/tcp, 0.0.0.0:9080->9080/tcp, 0.0.0.0:9092->9092/tcp, 0.0.0.0:29092->29092/tcp test-kafka
39d16d02b95c mysql:8.0.18 "docker-entrypoint.s…" 3 seconds ago Up 2 seconds 33060/tcp, 0.0.0.0:7777->3306/tcp dockerenv-mysql
______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Mongo Down, Killing Kafka
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
a6e9bea0393c dockerenv-kafka:test "supervisord -n" 3 seconds ago Up 1 second 0.0.0.0:2181->2181/tcp, 0.0.0.0:8083->8083/tcp, 0.0.0.0:9080->9080/tcp, 0.0.0.0:9092->9092/tcp, 0.0.0.0:29092->29092/tcp test-kafka
39d16d02b95c mysql:8.0.18 "docker-entrypoint.s…" 4 seconds ago Up 3 seconds 33060/tcp, 0.0.0.0:7777->3306/tcp dockerenv-mysql
____________________________________________________________________________________________________________________________________________________________
Kafka Down, Killing Postgres
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
39d16d02b95c mysql:8.0.18 "docker-entrypoint.s…" 6 seconds ago Up 4 seconds 33060/tcp, 0.0.0.0:7777->3306/tcp dockerenv-mysql
_____________________________________________________________________________________________________________________________
All done!
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
You can also depend on the test artifact to extend common base test classes:
libraryDependencies += "com.github.aaronp" %% "dockerenv" % "latest version" % "test" classifier "tests"
which gives you:
// the BaseXYZSpec classes ensure XYZ is started/stopped for your tests, and expose a 'dockerHandle' should you need to
// stop the services for run more complex scenarios, like testing failover/retries
class MyKafkaTest extends BaseKafkaSpec {
"Kafka" should {
"connect to a running kafka instance" in {
isDockerRunning() shouldBe true
val topic = "testTopic"
// insert your code here which needs to do something with kafka (e.g. publish/consume some data)
// here we just execute a script within the kafka container to demonstrate it's running by invoking
// 'kafka-topics.sh' script within the container via our listTopics.sh wrapper
val Success((0, listOutput)) = dockerHandle.runInScriptDir("listTopics.sh")
listOutput should not be(empty)
}
}
}