Control environment variables inside a Docker container

Issue

Control environment variables inside a Docker container with the Docker Pipeline plugin.

Environment

CloudBees Jenkins Enterprise
Pipeline plugin
Docker Pipeline plugin

Resolution

By default, when using the Docker Pipeline plugin the node’s environment variables will not be propagated to the docker container - since with Docker you want to get isolate environments. You can check this here

However, if at Node level (http/s:///computer//configure), under Node Properties, you add Environment variables, those [will be added to the container](https://github.com/jenkinsci/docker-workflow-plugin/blob/7084130bedfbdbb0b8e433f142571f93708bf61a/src/main/java/org/jenkinsci/plugins/docker/workflow/WithContainerStep.java#L124).

If you would like to override again what is injected at Node level then you will need to use withEnvstep.

node ('linux-agent') {
    withEnv(['PATH=/usr/local/Cellar/coreutils/8.25/libexec/gnubin:/usr/local/Cellar/gnu-sed/4.2.2/libexec/gnubin:/Users/fbelzunc/cloudbees/support/support-shinobi-tools:/Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home//bin:/Users/fbelzunc/bin:/usr/local/sbin:/usr/local/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/usr/local/MacGPG2/bin:/usr/local/sbin:/usr/local/Cellar/ruby/2.1.0/lib/ruby/gems/2.1.0/gems/bundler-1.6.5/bin:/usr/local/Cellar/ruby/2.1.0/lib/ruby/gems/2.1.0/gems/beaker-1.16.0/bin:/usr/local/Cellar/ruby/2.1.0/bin/:/path/testing']) {
        docker.image('maven:3.3.3-jdk-8').inside {
          sh 'echo $PATH'
          sh 'mvn --version'
        }
    }
    sh 'echo $PATH'
}