How to configure Gradle cache when running Jenkins with Docker - jenkins

Question

I'm working on building Jenkins pipeline for building a project with Gradle.
Jenkins has several slaves. All the slaves are connected to a NAS.
Some of the build steps run Gradle inside Docker containers while others run directly on the slaves.
The goal is to use as much cache as possible but I have also run into deadlock issues such as
Could not create service of type FileHasher using GradleUserHomeScopeServices.createCachingFileHasher().
> Timeout waiting to lock file hash cache (/home/slave/.gradle/caches/4.2/fileHashes). It is currently in use by another Gradle instance.

Answer 1

Due to the Gradle issue mentioned in the comment above, I do something like this — copying the Gradle cache into the container at startup, and writing any changes back at the end of the build:
pipeline {
agent {
docker {
image '…'
// Mount the Gradle cache in the container
args '-v /var/cache/gradle:/tmp/gradle-user-home:rw'
}
}
environment {
HOME = '/home/android'
GRADLE_CACHE = '/tmp/gradle-user-home'
}
stages {
stage('Prepare container') {
steps {
// Copy the Gradle cache from the host, so we can write to it
sh "rsync -a --include /caches --include /wrapper --exclude '/*' ${GRADLE_CACHE}/ ${HOME}/.gradle || true"
}
}
…
}
post {
success {
// Write updates to the Gradle cache back to the host
sh "rsync -au ${HOME}/.gradle/caches ${HOME}/.gradle/wrapper ${GRADLE_CACHE}/ || true"
}
}
}