Your first Testcontainers integration

From Testcontainers website, we learn that there is a simply way of running different supported JDBC databases with Docker:
https://www.testcontainers.org/usage/database_containers.html

Especially interesting part is JDBC-url based containers:
https://www.testcontainers.org/usage/database_containers.html#jdbc-url

It means that starting using Testcontainers in our project (once we add a dependency) is as simple as changing a few properties in Spring Boot:

@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT, properties = {
 "spring.datasource.url=jdbc:tc:postgresql:10-alpine://springio/workshop",
 "spring.datasource.driver-class-name=org.testcontainers.jdbc.ContainerDatabaseDriver"
})

If we split the magical JDBC url, we get:

• jdbc:tc: - this part says that we should use Testcontainers as JDBC provider
• postgresql:10-alpine:// - we use postgresql database, and we select PostgreSQL 10 from Docker Hub as the image
• springio/workshop - the host name (can be anything) is springio and the database name is workshop. You choose.

Add the following properties and run the test again. Fixed? Good!

Check the logs.

2018-05-25 16:40:52.897  INFO   --- [    Test worker] o.t.d.UnixSocketClientProviderStrategy   : Accessing docker with local Unix socket
2018-05-25 16:40:52.898  INFO   --- [    Test worker] o.t.d.DockerClientProviderStrategy       : Found Docker environment with local Unix socket (unix:///var/run/docker.sock)
2018-05-25 16:40:52.899  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : Docker host IP address is localhost
2018-05-25 16:40:53.137  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : Connected to docker: 
  Server Version: 18.03.1-ce
  API Version: 1.37
  Operating System: Docker for Mac
  Total Memory: 4948 MB
2018-05-25 16:40:54.471  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : Ryuk started - will monitor and terminate Testcontainers containers on JVM exit
        ℹ︎ Checking the system...
        ✔ Docker version should be at least 1.6.0
        ✔ Docker environment should have more than 2GB free disk space
        ✔ File should be mountable

As you can see, Testcontainers quickly discovered your environment and connected to Docker. It did some pre-flight checks as well to ensure that you have a valid environment.

Hint 1:

add the following line to your ~/.testcontainers.property file to disable the checks and speed up the tests:

checks.disable=true

Hint 2:

Changing PostgreSQL version is as simple as replacing 10-alpine with 9-alpine for example.

Try it, but don't forget that it will download the image from the internet, but only if it's not present on your computer.