feat: add support for custom scripts

[moabu]

Prepare

• Read PR guidelines
• Read license information

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Description

Target issue

closes #6969

Implementation Details

For JARs greater than 1MB

1. Create a configmap or secret for a shell script that contains instructions to pull the custom jar file:

   #!/bin/sh
   # This script will pull the custom jar file from a remote location
   # and place it in the correct location for the Jans Auth server to use it
   wget -O /opt/jans/jetty/jans-auth/custom/libs/mycustom.jar https://mydomain.com/mycustom.jar

   kubectl -n <namespace> create cm my-custom-jar --from-file=mycustomjar.sh

2. Mount the configmap or secret in your values.yaml under auth-server.volumes and auth-server.volumeMounts

   auth-server:
     volumeMounts:
       - name: my-custom-jar-volume
         mountPath: /tmp/mycustomjar.sh
         subPath: mymycustomjar.sh
     volumes:
       - name: my-custom-jar-volume
         configMap:
           name: my-custom-jar
     customScripts:
       - /tmp/mycustomjar.sh
   

3. Run helm install or helm upgrade if Jans has been already installed.

   helm upgrade <helm-release-name> janssen/janssen -n <namespace> -f values.yaml --version=1.0.x

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Test and Document the changes

• Static code analysis has been run locally and issues have been fixed
• Relevant unit and integration tests have been added/updated
• Relevant documentation has been updated if any (i.e. user guides, installation and configuration guides, technical design docs etc)

[iromli]

subPath should be mycustom.jar

[iromli]

May need to adjust defaultMode to add proper executable permission for the script. By default it's 420 (equivalent to 0644).