Image permission in jenkins docker agent

Question

I am using normal jenkins installation (NOT THE DOCKER IMAGE) on a normal AWS ec2 instance, with docker engine installed along side jenkins.

I have a simple jenkins pipeline like this:

pipeline {
    agent none 
    stages {
        stage('Example Build') {
            agent { docker {
                image 'cypress/base:latest'
                args '--privileged --env CYPRESS_CACHE_FOLDER=~/.cache'
            } } 
            steps {
                sh 'ls'
                sh 'node --version'
                sh 'yarn install'
                sh 'make e2e-test'
            }
        }
        
    }
}

this will make the pipeline fail in the yarn install step while installing cypress although all it's dependenices is satisfied from the cypress image.

ERROR LOG FROM JENKINS

error /var/lib/jenkins/workspace/Devops-Capstone-Project_master/node_modules/cypress: Command failed.

Exit code: 1

Command: node index.js --exec install

Arguments: 

Directory: /var/lib/jenkins/workspace/Devops-Capstone-Project_master/node_modules/cypress

Output:

Cypress cannot write to the cache directory due to file permissions


See discussion and possible solutions at

https://github.com/cypress-io/cypress/issues/1281


----------


Failed to access /.cache:


EACCES: permission denied, mkdir '/.cache'

After some investigation i found that although i have provided the environment variable "CYPRESS_CACHE_FOLDER=~/.cache" to override the default location in the root directory, and also provided the "--privileged" . it fails because for some reason jenkins and docker is forcing their args and user mapping from the jenkins host.

I have also tried providing "-u 1000:1000" to override the user mapping but it didn't work.

What could possibly be wrong? and any recommendations or work arounds about this issue?

Thanks,,

Answer 1

I have found a work around by creating a docker file to build the image and pass the jenkins user id and group to it as build arguments, as described here on this thread .

But this is not guaranteed to work on multiple nodes (master->slaves) jenkins installations as the jenkins user id and group may differ.