The following snippet shows the minimum code that is required to request a Docker Container in a Galasa test:

@Dockercontainer(image="library/httpd:latest", tag="http", start=true)
public IDockercontainer container1;

The code creates a Docker Container with an Apache HTTP Server running on port 80. Although this does not provide much, it does give a known target HTTP Server that you can start and stop in order to test how your application responds in those circumstances. By accessing the container1 field, you can find the IP address and port that was used for the container.

At the end of the test, the Docker Manager automatically stops and discards the Docker Container. If for some reason the test was not able to do this, the Docker Manager resource management routines perform the same clean up after the Galasa Ecosystem discovers the test has disappeared.

There is no limit in Galasa on how many Docker Containers can be used within a single test. The only limit is the number of Docker Containers that can be started in the Galasa Ecosystem. This limit is set by the Galasa Administrator and is typically set to the maximum number of containers that can be supported by the Docker Server or Swarm. If there are not enough slots available for an automated run, the run is put back on the queue in waiting state to retry. Local test runs fail if there are not enough container slots available.

Find the IP address and port by using the following code which provisions and starts an Apache HTTP server on port 80:

@Dockercontainer(image="library/httpd:latest")
public IDockercontainer httpcontainer;
...
InetSocketAddress port80 = httpContainer.getFirstSocketForExposedPort(80);

Stop and start your Apache HTTP Server to test how your application responds by using the following code:

@Dockercontainer(image="library/httpd:latest")
public IDockercontainer httpcontainer;
...
httpContainer.stop();

httpContainer.start();

Use the following code to execute a command within the Docker Container and return the resulting output:

@Dockercontainer(image="library/httpd:latest")
public IDockercontainer httpcontainer;
...
IDockerExec exec = httpContainer.exec("ls","-l","/var/log");
exec.waitForExec();
String output = exec.getCurrentOutput();

Use the following code to retrieve the container log:

@Dockercontainer(image="library/httpd:latest")
public IDockercontainer httpcontainer;
...
String log = httpContainer.getStdOut();

Currently, the Docker Manager supports only a single Docker Engine although it is planned to allow multiple Engines to be configured.
To allow local runs to access the local Docker Engine, you must add this property to the CPS and enable the TCP port of your local Docker Engine.
If the Docker Engine is not using the default TCP port, you must provide the docker.engine.port configuration property in the CPS.

The Docker Manager communicates with the Docker Engine via TCP. The Docker Engine needs to be configured to open the TCP port, which is usually 2375. If the port is not the default one, then this property needs to be provided in the CPS.

Currently, the Docker Manager supports only a single Docker Engine group called "default" although it is planned to allow multiple Engine groups to be configured.

To decouple Docker Registries from the Galasa test, this property allows the Docker Manager to search for images. The main reason being if the customer Docker Registry moves, only this property needs to change, instead of having to change the source code of lots of tests.

The registries are searched in order when looking for an image. When the image is located, the search stops.

If this property is provided in the CPS, the Docker Hub registry is not automatically appended. If it is required, then the DOCKERHUB id must be included.

If the docker.registry.ID.credentials CPS property is missing, the Docker Manager will attempt to use the credentials ID that is provided in docker.registry.credentials, if that is missing, then the default credentials ID of DOCKER will be used.

If the Docker Registry requires credentials for authentication, then the id for the credentials must be provided using the CPS property docker.registry.ID.credentials or docker.registry.credentials