Merge pull request #900 from ac-hibbert/PRE_CLEAR_INIT_GROOVY_D

Author: timja

README.md

@@ -188,6 +188,8 @@ FROM jenkins/jenkins:lts-jdk17
 COPY --chown=jenkins:jenkins custom.groovy /usr/share/jenkins/ref/init.groovy.d/custom.groovy
 ```
 
+If you need to maintain the entire init.groovy.d directory and have a persistent JENKINS_HOME you may run the docker image with `-e PRE_CLEAR_INIT_GROOVY_D=true`
+
 ## Preinstalling plugins
 
 ### Install plugins

jenkins.sh

@@ -2,6 +2,11 @@
 
 : "${JENKINS_WAR:="/usr/share/jenkins/jenkins.war"}"
 : "${JENKINS_HOME:="/var/jenkins_home"}"
+
+if [[ -n "${PRE_CLEAR_INIT_GROOVY_D}" ]]; then
+  rm -rf "${JENKINS_HOME}/init.groovy.d"
+fi
+
 : "${COPY_REFERENCE_FILE_LOG:="${JENKINS_HOME}/copy_reference_file.log"}"
 : "${REF:="/usr/share/jenkins/ref"}"