How to clone a github repository using Jenkins pipeline script?

Question

I am relatively new to the CI/CD concept.

I am trying to clone a Github repository using declarative pipeline in Jenkins (without SCM).

If i do it without any credentials then I can see in the console output that Jenkins is already trying to clone that repo but it takes extremely long . I can already see that in the Jenkins workspace I have a folder with the name of my github repo but it only has a .git folder inside it and it takes forever but never pulls the repo. After searching on the internet I found out that the permissions of accessing the repository were missing.

Then i added the credentials of my Github repo in Jenkins. I have the following script.

pipeline {
   agent any
   stages {
      stage('clone repo') {
          steps {
              withCredentials(usernamePassword(credentialsId :jenkins-user-github ,passwordVariable: 'GIT_PASSWORD', usernameVariable: 'GIT_USERNAME' )){
              // Get some code from a GitHub repository
              bat("""
              git config --global credential.username {GIT_USERNAME}
              git config --global credential.helper "!echo password={GIT_PASSWORD}; echo"
              git clone https://github.com/aakashsehgal/FMU.git

              echo "pulled the code"
              """)

          }


         }

         }
      }

}

But i get the following error:

Started by user Aakash Sehgal
Running in Durability level: MAX_SURVIVABILITY
[Pipeline] Start of Pipeline
[Pipeline] node
Running on Jenkins in C:\Program Files (x86)\Jenkins\workspace\GitHub
[Pipeline] {
[Pipeline] stage
[Pipeline] { (clone repo)
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
groovy.lang.MissingPropertyException: No such property: jenkins for class: groovy.lang.Binding
    at groovy.lang.Binding.getVariable(Binding.java:63)
    at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onGetProperty(SandboxInterceptor.java:270)
    at org.kohsuke.groovy.sandbox.impl.Checker$6.call(Checker.java:291)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:295)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:271)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:271)
    at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.getProperty(SandboxInvoker.java:29)
    at com.cloudbees.groovy.cps.impl.PropertyAccessBlock.rawGet(PropertyAccessBlock.java:20)
    at WorkflowScript.run(WorkflowScript:6)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.delegateAndExecute(ModelInterpreter.groovy:139)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.executeSingleStage(ModelInterpreter.groovy:663)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.catchRequiredContextForNode(ModelInterpreter.groovy:397)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.catchRequiredContextForNode(ModelInterpreter.groovy:395)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.executeSingleStage(ModelInterpreter.groovy:662)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:290)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.toolsBlock(ModelInterpreter.groovy:546)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.toolsBlock(ModelInterpreter.groovy:545)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:278)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withEnvBlock(ModelInterpreter.groovy:445)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withEnvBlock(ModelInterpreter.groovy:444)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:277)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withCredentialsBlock(ModelInterpreter.groovy:483)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withCredentialsBlock(ModelInterpreter.groovy:482)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:276)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.inDeclarativeAgent(ModelInterpreter.groovy:588)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.inDeclarativeAgent(ModelInterpreter.groovy:587)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:274)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.stageInput(ModelInterpreter.groovy:358)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.stageInput(ModelInterpreter.groovy:357)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:263)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.inWrappers(ModelInterpreter.groovy:615)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.inWrappers(ModelInterpreter.groovy:614)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:261)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withEnvBlock(ModelInterpreter.groovy:445)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.withEnvBlock(ModelInterpreter.groovy:444)
    at org.jenkinsci.plugins.pipeline.modeldefinition.ModelInterpreter.evaluateStage(ModelInterpreter.groovy:256)
    at ___cps.transform___(Native Method)
    at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.get(PropertyishBlock.java:74)
    at com.cloudbees.groovy.cps.LValueBlock$GetAdapter.receive(LValueBlock.java:30)
    at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.fixName(PropertyishBlock.java:66)
    at sun.reflect.GeneratedMethodAccessor321.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
    at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
    at com.cloudbees.groovy.cps.Next.step(Next.java:83)
    at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:174)
    at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:163)
    at org.codehaus.groovy.runtime.GroovyCategorySupport$ThreadCategoryInfo.use(GroovyCategorySupport.java:129)
    at org.codehaus.groovy.runtime.GroovyCategorySupport.use(GroovyCategorySupport.java:268)
    at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:163)
    at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$001(SandboxContinuable.java:18)
    at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:51)
    at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:185)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:400)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$400(CpsThreadGroup.java:96)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:312)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:276)
    at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:67)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:131)
    at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
    at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:59)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Finished: FAILURE

Any idea what am i missing here ?

Answer 1

You've a syntax error in using the username and password within the stage. You should've have it like ${GIT_USERNAME} and not {GIT_USERNAME} alone.

That being said, you need to explicitly mention to which branch you need to check out.

I assume you'd want to checkout to master branch by default. So use the below:

pipeline {
   agent any
   stages {
    stage('Checkout') {
      steps {
        script {
           // The below will clone your repo and will be checked out to master branch by default.
           git credentialsId: 'jenkins-user-github', url: 'https://github.com/aakashsehgal/FMU.git'
           // Do a ls -lart to view all the files are cloned. It will be clonned. This is just for you to be sure about it.
           sh "ls -lart ./*" 
           // List all branches in your repo. 
           sh "git branch -a"
           // Checkout to a specific branch in your repo.
           sh "git checkout branchname"
          }
       }
    }
  }
}

If you want to checkout to a specific branch by default then use the below in your pipeline stage. With the below part, you won't need to run git checkout command separately.

pipeline {
   agent any
   stages {
        stage('Checkout') {
            steps {
                checkout([$class: 'GitSCM', branches: [[name: '*/branchname']], doGenerateSubmoduleConfigurations: false, extensions: [], submoduleCfg: [], userRemoteConfigs: [[credentialsId: 'jenkins-user-github', url: 'https://github.com/aakashsehgal/FMU.git']]])
                sh "ls -lart ./*"
            }
        }     
    }
}