CloudFoundry and JDK

I'm struggling with the deployment of a spring app that needs to compile java code during runtime. My app calls the javac command when a user submits a solution to a problem, so it can later run java <the file that javac has generated>

I'm deploying to cloud foundry and using the java-buildpack, but unfortunately, it doesn't come with JDK, only JRE is available and that thing has no javac or java commands available.

Do you guys know a way on how to add JDK to cloud foundry, without having to write my own custom buildpack.

Thanks

I would suggest you use multi-buildpack support and use the apt-buildpack to install a JDK. It should work fine alongside the JBP. It just needs to be first in the list.

https://github.com/cloudfoundry/apt-buildpack

Example:

1. Create an apt.yml.

    ---
    packages:
    - openjdk-11-jdk-headless
   

2. Bundle that into your JAR, jar uf path/to/your/file.jar apt.yml. It should be added to the root of the JAR, so if you jar tf path/to/your/file.jar you should see just apt.yml and nothing prefixed to it.

3. Update your manifest.yml. Add the apt-buildpack first in the list.

    ---
    applications:
    - name: spring-music
      memory: 1G
      path: build/libs/spring-music-1.0.jar
      buildpacks:
      - https://github.com/cloudfoundry/apt-buildpack#v0.2.2
      - java_buildpack
   

4. Then cf push. You should see the apt-buildpack run and install the JDK. It'll then be installed under ~/deps/0/lib/jvm/java-11-openjdk-amd64. It does not appear to end up on the PATH either, so use a full path to javac or update the path.