If a global environment variable is defined it is not possible to override it with arguments passed in to the docker.image(...).inside(...) step. It appears to be because environment variables from the process added to the docker launch arguments after any user specified arguments here.

The solution could simply be to put user args last assuming it's okay / secure for users to have the ability to override any of the automatically injected arguments.

To reproduce:

1. Create a global environment variable MY_VAR=value1
2. Create a pipeline job with the following script that sets MY_VAR=value2 as an image arguments

   • pipeline {
         agent {
             label "docker"
         }
     
         stages {
             stage('Build') {
                 steps {
                     script {
                         docker.image('<image>').inside('-e MY_VAR=value2') { 
                             sh 'env | grep MY_VAR'
                         }
                     }
                 }
             }
         }
     }
     

1. Observe the result. It prints MY_VAR=value1 instead of MY_VAR=value2

   14:55:39  [Pipeline] withDockerContainer
   14:55:39  jknn2t-mdjrvo does not seem to be running inside a container
   14:55:39  $ docker run -t -d -u 78572:20 -e MY_VAR=value2 -w /var/appl/jenkins/workspace/sle/mrichar2_var_ordering -v /var/appl/jenkins/workspace/sle/mrichar2_var_ordering:/var/appl/jenkins/workspace/sle/mrichar2_var_ordering:rw,z -v /var/appl/jenkins/workspace/sle/mrichar2_var_ordering@tmp:/var/appl/jenkins/workspace/sle/mrichar2_var_ordering@tmp:rw,z -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** <image> cat
   14:55:39  $ docker top 8a93013c14625256f17f5fc2d71132333ac6aa35962da9540b1a8171a934c659 -eo pid,comm
   14:55:39  [Pipeline] {
   14:55:39  [Pipeline] sh
   14:55:40  + env
   14:55:40  + grep MY_VAR
   14:55:40  MY_VAR=value1
   14:55:40  [Pipeline] }
   14:55:40  $ docker stop --time=1 8a93013c14625256f17f5fc2d71132333ac6aa35962da9540b1a8171a934c659
   14:55:41  $ docker rm -f 8a93013c14625256f17f5fc2d71132333ac6aa35962da9540b1a8171a934c659
   14:55:41  [Pipeline] // withDockerContainer
   14:55:41  [Pipeline] }
   14:55:41  [Pipeline] // script
   14:55:41  [Pipeline] }
   14:55:41  [Pipeline] // stage
   14:55:41  [Pipeline] }
   14:55:41  [Pipeline] // node
   14:55:41  [Pipeline] End of Pipeline