kcm-ext-example

kcm-ext-example is an example extension for KCM/Guacamole that demonstrates how arbitrary parameter tokens can be generated and injected at connection time.

As written, the example injects a token called EXAMPLE_TOKEN that contains the user's username. This can be replaced by essentially any Java code that ultimately produces a string, and that code can take into account the current user's identity, the details of their successful authentication attempt that resulted in their KCM session, etc.

Building the extension

You will need Maven and a copy of the JDK to build extensions for KCM/Guacamole. To build this extension, run:

$ mvn package

The result of the build will be a .jar file within the target/ directory:

$ ls target/
classes            generated-test-sources      maven-archiver  test-classes
generated-sources  kcm-ext-example-2.19.0.jar  maven-status
$

This extension can then be used with KCM by copying the .jar file into place:

• If KCM was installed natively (using RPMs), copy the .jar file to /etc/guacamole/extensions/ of your KCM server and restart the web application.

• If KCM was installed using kcm-setup.run or the Docker images, the .jar file should be copied somewhere reasonable on the server and then mounted into place using a volume mount. If using kcm-setup.run or Docker Compose, this will mean modifying your docker-compose.yml such that the guacamole container points at the extension:

  services:
  
      guacamole:
          image: keeper/guacamole:2
          restart: unless-stopped
          ...
          volumes:
              ...
              - "/path/to/kcm-ext-example-2.19.0.jar:/etc/guacamole/extensions/kcm-ext-example.jar:ro"
  

  To add a new volume mount like this, you will need to recreate the Docker container. kcm-setup.run will do this for you automatically when you use kcm-setup.run apply. Docker Compose will do this for you automatically when you use docker-compose up.