CODEWITHSUNDEEP
gitjenkinsjenkins-pipeline
chad
chad

Reputation: 443

Jenkinsfile: git rev-parse --abbrev-ref HEAD returns HEAD

I am new to jenkins/devops; I am following this example. When I locally do (from the terminal):

git rev-parse --abbrev-ref HEAD

I get the current branch's name. However from within Jenkinsfile, in the logs I am getting:

HEAD

Been researching online for a while and couldn't find the reason so far. What are potential causes for this outcome?

Additional Details

In my jenkinsfile, i am trying to get the current git branch's name (the one that triggered the webhook) and then pipe it inside 'git branch' command, so code is as follows:

pipeline {
agent {
    label 'ubuntu'
}
stages {
    stage('check') {
    steps {
            script {
               env.GIT_BRANCH_NAME=sh(returnStdout: true, script: "git rev-parse --abbrev-ref HEAD").trim()
            }

            sh 'echo BRANCH_NAME ${GIT_BRANCH_NAME}'
            git branch: GIT_BRANCH_NAME, credentialsId: '******', url: 'https://*****/*****/*****.git'
      }
....
}

In the line

sh 'echo BRANCH_NAME ${GIT_BRANCH_NAME}'

Returns HEAD

I found a way around this using git name-rev --name-only HEAD and modified the script code to: 

script {
    env.GIT_BRANCH_PATH=sh(returnStdout: true, script: "git name-rev --name-only HEAD").trim()
    env.GIT_BRANCH_NAME=GIT_BRANCH_PATH.split('remotes/origin/')[1]
}

Now I get the right branch name and the steps work, but I would rather have a less hacky way of doing things.

What is the best method to achieve what I want to achieve using best practices?

PS I am not using multi-branching pipeline and the requirements were to not use multi-branching.

Upvotes: 42

Views: 22100

Answers (4)

bkidd
bkidd

Reputation: 590

Problem:

As torek mentioned, if you've checked out a commit (vs a branch) you are in a "detached HEAD" state (HEAD detached at 123abc).

Why?

--abbrev-ref returns a non-ambiguous short name of the objects name. The current object is the commit you checked out, not a branch. Further, git wouldn't be able to determine which branch you wanted anyway because the commit you checked out could easily live in multiple branches.

Solution:

I would use Vijay Ramaswamy's suggestion, however, you could also hard-code the branch name in your script:

env.GIT_BRANCH_NAME='my-branch-name'

or more simply

git branch: 'my-branch-name', credentialsId: '******', url: 'https://*****/*****/*****.git'

Upvotes: 7

Oleksandr Bondarenko
Oleksandr Bondarenko

Reputation: 2018

The solution that I've found for this situation is:

checkout([$class: 'GitSCM', branches: [[name: '*/' + branch]], doGenerateSubmoduleConfigurations: false, extensions: [[$class: 'LocalBranch', localBranch: "**"]], submoduleCfg: [], userRemoteConfigs: [[credentialsId: 'cred', url: '[email protected]:repofolder/repo.git']]])

The key here is [$class: 'LocalBranch', localBranch: "**"]. It allows to checkout a branch not a revision.

The source for it is taken from here.

Upvotes: 5

Vijay Ramaswamy
Vijay Ramaswamy

Reputation: 286

I am probably late in responding, but there is potentially a simpler way. Ensure that you select "Check out to specific local branch" under additional behaviors within your Git configuration. This will ensure that git checks out to the exact branch you are tracking, and your original command "git rev-parse --abbrev-ref HEAD" will work fine.enter image description here

Upvotes: 26

Kvk
Kvk

Reputation: 524

If you are using the multibranch pipeline, branch name should be available in the environment variables as env. BRANCH_NAME. you can use sh 'printenv' inside your step to print all the available environment variables

Upvotes: 1

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