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  1. Jenkins
  2. JENKINS-60353

Non-mergable Pull-request Contents Get into GH Cache with False-Positive 404

    Details

    • Similar Issues:

      Description

      How to reproduce:

      Use multibranch-pipeline workflow with merge PR strategy

      1. Create a branch, develop it and make it nonmergable into the target branch
      2. Push the branch and open the Pull Request in GH
      3. Find out that the branch is not-mergeable
      4. Fix the code, push the newer revision

      Expected Result:

      The pipeline is triggered.

      Actual Result:

      1. On step #2 Jenkins gets the 404 in the request to ...refs/pull/<id>/merge/contents
      2. The 404 is cached
      3. On the step 4 it does not query GH but rather returns a cryptic error of 'Jenkins File not found' although it does not check for it at all

      Proposed solution: do not check for the contents of the "refs./..../merge" URL if the PR is not mergable.

      Versions:

      Jenkins 2.190.1
      GitHub Branch Source Plugin 2.5.8+ (some irrelevant local patches)

      Here is how we figured out what was happening:

      1. Get the repro of the bug
      2. Jump to the jenkins master node and create a copy of github cache dir, namely "${JENKINS_HOME}/org.jenkinsci.plugins.github_branch_source.GitHubSCMProbe.cache"
      3. grep for the pull request id in the *.0 files to figure out the  request id (prefix before the '.0') of the exchange with Github 
      4. zcat the file of the exchange (<reqid>.1) and see that Jenkins checks the refs/pull/<prid>/merge/contents and gets 404
      5. Jenkins never consults anything after getting this response until the cache entry with 404 is purged, but writes a cryptic message like 'Jenkinsfile not found' and (possibly) the lines saying that the PR branch is dead, thus being removed from the list of branches to run the build against,

      While surfing looking for the similar bugs, I noticed several that might be related to those ones, especially the first one.

      https://issues.jenkins-ci.org/browse/JENKINS-48571

      https://issues.jenkins-ci.org/browse/JENKINS-46290

      https://issues.jenkins-ci.org/browse/JENKINS-54126

      https://issues.jenkins-ci.org/browse/JENKINS-57206

      https://issues.jenkins-ci.org/browse/JENKINS-57411

       

       

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          Karl Shultz
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          Karl Shultz
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          Karl Shultz
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          Karl Shultz

          Issue Links

            Activity

            Hide
            kshultz Karl Shultz added a comment -

            For the record, converting the plugin to use okhttp3 did not solve this problem.

            Show
            kshultz Karl Shultz added a comment - For the record, converting the plugin to use okhttp3 did not solve this problem.
            Hide
            kshultz Karl Shultz added a comment -

            Liam Newman has been able to recreate this behavior using a test in github-api. There's a draft PR demonstrating it.

            Show
            kshultz Karl Shultz added a comment - Liam Newman has been able to recreate this behavior using a test in github-api. There's a draft PR demonstrating it .
            Hide
            bitwiseman Liam Newman added a comment - - edited

            To Be Clear: This is a bug in the GitHub API. The problem is described in https://github.com/github-api/github-api/pull/669 .

            The linked PR (https://github.com/github-api/github-api/pull/665) now shows a workaround that should work for all scenarios. I think can't be done at the Jenkins plugin level. It must be fixed at the github-api library level. But this is probably a good thing as the Jenkins workarounds are only bandaids.

            We'll do the work to upgrade this dependency (already in progress) and this problem will go away.

            Show
            bitwiseman Liam Newman added a comment - - edited To Be Clear: This is a bug in the GitHub API. The problem is described in https://github.com/github-api/github-api/pull/669 . The linked PR ( https://github.com/github-api/github-api/pull/665 ) now shows a workaround that should work for all scenarios. I think can't be done at the Jenkins plugin level. It must be fixed at the github-api library level. But this is probably a good thing as the Jenkins workarounds are only bandaids. We'll do the work to upgrade this dependency (already in progress) and this problem will go away.
            Hide
            bitwiseman Liam Newman added a comment -

            The fix for this issue has been merged and will be released in the next day or two in github-branch-source v2.6.0.

            If you want to try it out now:
            install github-api-plugin 1.6.0
            and then install the hpi from: https://repo.jenkins-ci.org/incrementals/org/jenkins-ci/plugins/github-branch-source/2.5.9-rc1028.3059575bf1cc/

            Show
            bitwiseman Liam Newman added a comment - The fix for this issue has been merged and will be released in the next day or two in github-branch-source v2.6.0. If you want to try it out now: install github-api-plugin 1.6.0 and then install the hpi from: https://repo.jenkins-ci.org/incrementals/org/jenkins-ci/plugins/github-branch-source/2.5.9-rc1028.3059575bf1cc/
            Hide
            bitwiseman Liam Newman added a comment -

            Vladimir Kuklin
            Github-branch-source-plugin v2.6.0

            Show
            bitwiseman Liam Newman added a comment - Vladimir Kuklin Github-branch-source-plugin v2.6.0

              People

              • Assignee:
                kshultz Karl Shultz
                Reporter:
                vkuklinatjoom Vladimir Kuklin
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                Dates

                • Created:
                  Updated:
                  Resolved: