# Step 4: Your first Testcontainers integration

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

An especially interesting part are JDBC-URL based containers:\
<https://www.testcontainers.org/usage/database_containers.html#jdbc-url>

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

```java
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT, properties = {
 "spring.datasource.url=jdbc:tc:postgresql:14-alpine://testcontainers/workshop"
})
```

If we split the magical JDBC url, we see:

* `jdbc:tc:` - this part says that we should use Testcontainers as JDBC provider
* `postgresql:14-alpine://` - we use a PostgreSQL database, and we select the correct PostgreSQL image from the Docker Hub as the image
* `testcontainers/workshop` - the host name (can be anything) is `testcontainers` and the database name is `workshop`. Your choice!

After adding the properties and run the test again. Fixed? Good!

Check the logs.

```
    13:30:59.352  INFO   --- [    Test worker] o.t.d.DockerClientProviderStrategy       : Found Docker environment with local Npipe socket (npipe:////./pipe/docker_engine)
    13:30:59.369  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : Docker host IP address is localhost
    13:30:59.431  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : Connected to docker: 
      Server Version: 20.10.11
      API Version: 1.41
      Operating System: Docker Desktop
      Total Memory: 3929 MB
    13:31:03.294  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : Ryuk started - will monitor and terminate Testcontainers containers on JVM exit
    13:31:03.295  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : Checking the system...
    13:31:03.296  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : ✔ Docker server version should be at least 1.6.0
    13:31:03.588  INFO   --- [    Test worker] org.testcontainers.DockerClientFactory   : ✔ Docker environment should have more than 2GB free disk space
```

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.properties` file to disable these checks and speed up the tests:

```
checks.disable=true
```

## Hint 2:

Changing the PostgreSQL version is as simple as replacing `14-alpine` with, for example, `10-alpine`. Try it, but don't forget that it will download the new image from the internet, if it's not already present on your computer.