This is a "standard" Spring Boot project.
It shows how to test a server that uses a trust-store and / or keystore for security.
The relevant Karate documentation can be found here: X509 Certificate Authentication.
Run the server from the IDE or via Maven using this command:
mvn -Dexec.mainClass=io.karatelabs.examples.ssl.TestService compile exec:java
This will start an HTTPS server on port 8080.
Now you can run the two Karate tests individually from the IDE.
Or by using the SslRunner JUnit helper.
mvn test -Dtest=SslRunner
You can also run the test suite that will start the server automatically.
mvn test