How to merge a successful build of a pull request using a Jenkinsfile

Question

TL;DR: Given the following declarative Jenkinsfile, how can I merge the pull request following a successful build? http://pastebin.com/uivA0MqF

In the (Multibranch) Job configuration, under Branch Source > Advanced I have the following setup:

And in GitHub I have a web hook that listens to pull request and push events.

Edit: I have attempted the following, but it currently fails with a syntax error:

def gitPullRequestNumber = null
...
...
stage ("Merge pull request") {
     steps {
        gitPullRequestNumber = sh "git ls-remote origin 'pull/*/head:develop'"
        sh "curl -X PUT -d '{\'commit_title\': \'Merge pull request\'}'  <<GIT REPO URL>>/pulls/${gitPullRequestNumber}/merge?access_token=<<ACCESS-TOKEN"
     }
}

The error:

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:

WorkflowScript: 58: Expected a step @ line 58, column 13.
               gitPullRequestNumber = sh "git ls-remote origin 'pull/*/head:develop'"
               ^

1 error

Background:

We have a master branch and a develop branch. Developers will be doing their pull requests against the develop branch where tests will be run. If the tests pass, the pull request should be merged into the branch. Review of the code is done before a pull request is opened. When decided, the develop branch is merged to the master branch. In the future there may even be only a single branch.

I understand that some may say that it is a good thing this doesn't happen but this is what we are currently trying to achieve.

As mentioned, this all works fine and the job starts and uses the Jenkinsfile for checking out the repo based on direct pushes and/or pull requests, the build starts, the tests run and so on... however the missing piece is merging the pull requests back.

You can't assign variables in Declarative Pipeline, except for within `script` blocks. — Christopher Orr, Mar 08 '17 at 16:50

score 0 · Answer 1 · answered Mar 08 '17 at 08:45

0

Use git commands to merge as written

#Checkout main branch
git checkout master 

#Merge it with pull request (insert your pull id)
git merge --no-ff pull/ID/head:develop

#TEST Local Merge Branch Compilation If Desired
#msbuild ...

#Push merged information back to git
git push origin master

answered Mar 08 '17 at 08:45

SACn

1,862
1
14
29

Finding out the pull request number as part of theJenkinsfile is exactly what am I asking for. – Idan Adar Mar 08 '17 at 09:14
Try `git ls-remote origin 'pull/*/head:develop'` as per [how to list all pull request with count of files changed](http://stackoverflow.com/questions/40182366/how-to-list-all-pull-request-with-count-of-files-changed). Or consider using ruby gem [git-pulls](https://github.com/schacon/git-pulls) – SACn Mar 08 '17 at 09:21
Sorry for being dense, but does `git ls-remote origin 'pull/*/head:develop'` provide the number of the current pull request that is being tested? – Idan Adar Mar 08 '17 at 11:26
I've tried, but this currently fails. See my edited question. – Idan Adar Mar 08 '17 at 13:50
FWIW, `git merge @{-1}` will merge from the previous branch you were on (though this might not work with the Git plugin, as it checks out commits, rather than branches). https://stackoverflow.com/a/17819027/234938 seems to have an answer. – Christopher Orr Mar 08 '17 at 17:01

Idan Adar · Accepted Answer · 2018-01-09T14:36:09.227

After also checking the checkbox for Build origin PRs (merged with base branch) this enabled a Jenkins-provided environment variable, $CHANGE_ID that in the case of a pull request, is the pull request number. This could then be used in the stage:

stage ("Merge pull request") {
    steps { 
        withCredentials([usernamePassword(credentialsId: 'credential-value', usernameVariable: 'ACCESS_TOKEN_USERNAME', passwordVariable: 'ACCESS_TOKEN_PASSWORD',)]) {
            sh "curl -X PUT -d '{\"commit_title\": \"Merge pull request\"}'  https://github.ibm.com/api/v3/repos/org-name/repo-name/pulls/$CHANGE_ID/merge?access_token=$ACCESS_TOKEN_PASSWORD"
        }
    }
}

Update: to verify the merge was actually successful:

script {
    sh "curl -o - -s -w \"\n%{http_code}\n\" -X PUT -d '{\"commit_title\": \"Merge pull request\"}'  https://github.ibm.com/api/v3/repos/****/****/pulls/$CHANGE_ID/merge?access_token=$JENKINSBOT_PSW | tail -1 > mergeResult.txt"

    def mergeResult = readFile('mergeResult.txt').trim()
    if (mergeResult != "200") {
        error "Unable to merge!"
    } else {
        // Send a Slack message, etc
      }
    }
}

How to merge a successful build of a pull request using a Jenkinsfile

2 Answers2

Linked