Testing acme4j

Integration Tests

acme4j provides a number of integration tests. These tests are not executed by maven by default, as they require Docker on the build machine.

To run them, install Docker and make it available to your user. Then invoke mvn -Pci verify to run the integration tests. The test will build images of the current Pebble ACME test server, and an internal test server that provides a configurable HTTP and DNS server for Pebble.

If you change into the acme-it project directory, you can also build, start and stop the test servers with mvn docker:build, mvn docker:start and mvn docker:stop, respectively. While the test servers are running, you can also run the integration tests in your IDE. mvn docker:remove finally removes the test server images.


The acme4j-it module contains a small and very simple test server called BammBamm, which can be used to verify challenges. In the default configuration, it uses these ports:

  • 14001: Provides a simple REST-like interface for adding and removing challenge tokens and DNS records. This port is exposed.
  • 53 (UDP): A simple DNS server for resolving test domain names, and providing TXT records for dns-01 challenges.
  • 5001: A simple TLS-ALPN server that responds with certificates for tls-alpn-01 challenges.
  • 5002: A simple HTTP server that responds with tokens for http-01 challenges.

To run this server, you can use the Docker image mentioned above. You could also run the server directly, but since the DNS server is listening on a privileged port, it would need to be reconfigured first. Also, if you run BammBamm with OpenJDK 8, make sure to add the correct alpn-boot.jar version to your boot classpath in order to use the TLS-ALPN server.

The BammBammClient class can be used to set the challenge responses and DNS records via the REST interface on port 14001.


It is also possible to run some tests against the Boulder ACME server, but the setup is a little tricky.

First, build and start the integration test Docker servers as explained above. When the servers are started, find out the IP address of the BammBamm server:

docker inspect bammbamm -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}'

Now set up a Docker instance of Boulder. Follow the instructions in the Boulder README. When you are ready to start it, set the FAKE_DNS env variable to the IP address of BammBamm you have found before.

The Boulder integration tests can now be run with mvn -P boulder verify.

For a local Boulder installation, just make sure that FAKE_DNS is set to You’ll also need to expose the ports 5001 and 5002 of BammBamm by changing the acme4j-it/pom.xml accordingly.