How to override global "environment {}" Jenkins Variables in a stage?

[irl]

I'm trying to set up an automated Jenkins pipeline for the Development & Staging branches within our Git repository. I have most of the pipeline working. But I do not know how to override globally set environment {} variables depending on the git branch.

This is my Jenkinsfile:

pipeline {
  agent any
environment {

dev_mongo_url = credentials('DEV_MONGO_URL')

stg_mongo_url = credentials('STG_MONGO_URL')

}
stages {
stage('Env Setup') {
  steps {

    script
    {
    if (env.BRANCH_NAME == 'bugfix/*' || env.BRANCH_NAME == 'feature/*' || env.BRANCH_NAME =='development' || env.BRANCH_NAME =='hotfix/*') {
        env.environment = 'development' 
        echo 'Build & deployment to development environment'
        }


    if (env.BRANCH_NAME == 'staging'){
        env.environment = 'staging'
        echo 'Build & deployment to staging environment'
        
    }

}

}

}
stage('Migration') {
  when {
    anyOf {
      branch 'development';
      branch 'feature/*';          
      branch 'staging'
     }
  }
  steps {
    echo "Installing the project NodeJS dependencies..."
    sh 'npm ci'
    echo "Executing the MongoDB migration script & displaying the status..."
    dir('db-migrations') {
      sh 'npm ci'
      sh('npm run migrate --silent -- --mongodb-url=$mongo_url')
      sh 'npm run migrate:status'
    }

  }
}

}

}

Within the above pipeline, I have the Env Setup stage, which assigns the environment type variable (development/staging) depending on the git branch. We have two MongoDB instances - one for development & one for the staging environment. I have defined both of the MongoDB server URL's under the environment {} block. Now, I want to dynamically connect to the dev/staging mongo servers in the Migration stage, depending on the environment type, and apply the migrations. I'm trying to automatically inject $mongo_url value from the dev_mongo_url & stg_mongo_url global variables depending on the environment. I'm stuck, and I have no clue how to achieve it.

Any help?

[kalena]

See the https://www.jenkins.io/doc/book/pipeline/jenkinsfile/#setting-environment-variables-dynamically . I think this will answer your question. Here is the snippet of example code from those docs:

pipeline {
    agent any 
    environment {
        // Using returnStdout
        CC = """${sh(
                returnStdout: true,
                script: 'echo "clang"'
            )}""" 
        // Using returnStatus
        EXIT_STATUS = """${sh(
                returnStatus: true,
                script: 'exit 1'
            )}"""
    }
    stages {
        stage('Example') {
            environment {
                DEBUG_FLAGS = '-g'
            }
            steps {
                sh 'printenv'
            }
        }
    }
}

So your code might end up looking something like this:

pipeline {
    agent any 
    environment {
        mongo_url = """${
            switch(env.BRANCH_NAME) {
                case 'bugfix/*'
                case 'feature/*'
                case 'development'
                case 'hotfix/*'
                    'YOUR_DEV_MONGO_URL_HERE'
                    break
                case 'staging'
                    'YOUR_STAGING_MONGO_URL_HERE'
                    break
            }"""
    }
}