Jenkins Declarative Pipeline throws NullPointerException when I use withCredentials

Question

I have a small pipeline that performs some GIT actions. I'm trying to use ssh as the protocol to communicate, so I defined the private key in the JenkinsServer and I have everything working fine.

    stage('Some Stage'){
      steps{
        withCredentials([[$class: 'SSHUserPrivateKeyBinding', credentialsId: "${params.credentialsId}", usernameVariable: 'GIT_USERNAME']]){
          script{
           // Do some git operations...
          }
       }
  }

If I remove the withCredentials from here the code works as fine, but I have to set the username hard coded in the git push commands. I want to fetch the username from the credentials instead. but my jenkins always throws a NPE without any other message.

I'm totally lost in this

Answer 1

Try the below and see if it helps. You can then refer username from credentials using GIT_CREDENTIALS_USR and password using GIT_CREDENTIALS_PSW

stage('Some Stage'){

      environment {
                GIT_CREDENTIALS = credentials('<credentialsID>')
      }
      steps{
         script{
           // Do some git operations...
        }
    }
}