Jenkins + Git:只有当PR在子目录中引入更改时才构建

Question

我们有一个大型的单一项目，里面有多个项目(A和B)。目前，我已经将Jenkins设置为一个多分支管道项目，用于监视PRs的monorepo。如果创建了一个PR，Jenkins就会同时构建A和B。

现在，我希望Jenkins更聪明，只有当PR中的任何更改导致A/目录发生变化时，才能构建项目A。事实证明这是非常困难的。

when { changeset "A/" }只检查上次提交是否更改了A/中的文件，而没有检查PR是否更改了A/中的文件。

因此，我使用https://issues.jenkins-ci.org/browse/JENKINS-54285使它变得更聪明，并做到了：

when { expression { return sourceChanged("A/") } }

将sourceChanged定义为：

def boolean sourceChanged(String module) {
    if (env.CHANGE_TARGET == null)
        return true;

    def MASTER = sh(returnStdout: true, script: "git rev-parse origin/${env.CHANGE_TARGET}").trim()
    def HEAD = sh(returnStdout: true, script: "git show -s --no-abbrev-commit --pretty=format:%P%n%H%n HEAD | tr ' ' '\n' | grep -v ${MASTER} | head -n 1").trim()

    return sh(returnStatus: true, script: "git diff --exit-code --name-only ${MASTER}...${HEAD} {module}") == 1;
}

但是，无论我如何尝试，我都无法获得CHANGE_TARGET的提交哈希。我总是从以下错误中得到一些信息：

git rev-parse origin/master
fatal: ambiguous argument 'origin/master': unknown revision or path not in the working tree.

为什么Git不能找到master、origin/master、refs/head/master等(我都试过了)？有更简单的方法来完成我想做的事情吗？

我使用的jenkins/jenkins:lts来自码头枢纽以及BitBucket分支源码插件。

以下是相关的Jenkins日志序列，如果有帮助的话：

Fetching changes from 2 remote Git repositories
 > git config remote.origin.url http://bitbucket.ccm.com:7990/scm/JUP/jt.git # timeout=10
Fetching without tags
Fetching upstream changes from http://bitbucket.ccm.com:7990/scm/JUP/jt.git
 > git --version # timeout=10
using GIT_ASKPASS to set credentials 
 > git fetch --no-tags --progress -- http://bitbucket.ccm.com:7990/scm/JUP/jt.git +refs/pull-requests/9/from:refs/remotes/origin/PR-9
 > git config remote.upstream.url http://bitbucket.ccm.com:7990/scm/JUP/jt.git # timeout=10
Fetching without tags
Fetching upstream changes from http://bitbucket.ccm.com:7990/scm/JUP/jt.git
using GIT_ASKPASS to set credentials 
 > git fetch --no-tags --progress -- http://bitbucket.ccm.com:7990/scm/JUP/jt.git +refs/heads/master:refs/remotes/upstream/master
Merging remotes/upstream/master commit 7ef64efeb0fb19d8931a684f147666ae681b4ddf into PR head commit 47600816c0dca3e5555e417085ab2052453a39b2
Enabling Git LFS pull
 > git config core.sparsecheckout # timeout=10
 > git checkout -f 47600816c0dca3e5555e417085ab2052453a39b2
 > git config --get remote.origin.url # timeout=10
using GIT_ASKPASS to set credentials 
 > git lfs pull origin
 > git merge 7ef64efeb0fb19d8931a684f147666ae681b4ddf # timeout=10
 > git rev-parse HEAD^{commit} # timeout=10
Merge succeeded, producing 47600816c0dca3e5555e417085ab2052453a39b2
Checking out Revision 47600816c0dca3e5555e417085ab2052453a39b2 (PR-9)
Enabling Git LFS pull
 > git config core.sparsecheckout # timeout=10
 > git checkout -f 47600816c0dca3e5555e417085ab2052453a39b2
 > git config --get remote.origin.url # timeout=10
using GIT_ASKPASS to set credentials 
 > git lfs pull origin
Commit message: "l"
[Pipeline] withEnv
[Pipeline] {
[Pipeline] sh
+ docker inspect -f . registry.ccm.com:7991/jt:1.0
.
[Pipeline] withDockerContainer
Jenkins seems to be running inside container fdc7e8eec5ea708e59cebe4682651bc5192478b95de803b5981edd222f39af97
$ docker run -t -d -u 1000:979 -v $PWD:/build_env -v $HOME/.ssh:/home/docker_user/.ssh -w /build_env --add-host civm3:10.33.67.183 -e UNIX_USER=jtbuild -w /var/jenkins_home/workspace/jt_PR-9@2 --volumes-from fdc7e8eec5ea708e59cebe4682651bc5192478b95de803b5981edd222f39af97 -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** registry.ccm.com:7991/jt:1.0 cat
$ docker top c7bb23bbc91119c2b1875ab2a9186ae34da1754f2b8ae42f758594227ff77137 -eo pid,comm
[Pipeline] {
[Pipeline] sh
+ git rev-parse origin/master
fatal: ambiguous argument 'origin/master': unknown revision or path not in the working tree.

我只想访问Jenkinsfile中的两个相关提交in：7ef64efeb0fb19d8931a684f147666ae681b4ddf和47600816c0dca3e5555e417085ab2052453a39b2！

Answer 1

好吧，我终于解决了。

它似乎(请纠正我，如果我的术语不正确)，Jenkins做了所谓的裸露克隆，这意味着你将无法访问任何裁判，除非你具体获取他们。因此，您将无法访问您的分支名称，无论是本地的还是远程的。

键在日志的这两行中：

> git fetch --no-tags --progress -- http://bitbucket.ccm.com:7990/scm/JUP/jt.git +refs/pull-requests/9/from:refs/remotes/origin/PR-9 
> git fetch --no-tags --progress -- http://bitbucket.ccm.com:7990/scm/JUP/jt.git +refs/heads/master:refs/remotes/upstream/master

下面是上述两个命令的简短、带注释的版本：

> git fetch the PR ref, store it as 'origin/PR-9'
> git fetch master ref, store it as 'upstream/master'

因此，两个感兴趣的提交被存储在origin/PR-9和upstream/master中。

方便地，Jenkins环境变量BRANCH_NAME和CHANGE_TARGET分别包含PR-9和master。

因此，Jenkinsfile应该使用以下内容：

def boolean sourceChanged(String module) {
    def target_branch = env.CHANGE_TARGET;
    def pr_ref        = env.BRANCH_NAME;

    if (target_branch == null) {
        echo "No target branch defined...";
        return true;
    }

    def TARGET = sh(returnStdout: true, script: "git rev-parse upstream/${target_branch}").trim()
    def HEAD   = sh(returnStdout: true, script: "git rev-parse origin/${pr_ref}").trim()

    echo "Checking for source changes between ${TARGET} (${target_branch}) and ${HEAD} (${pr_ref})...";
    return sh(returnStatus: true, script: "git diff --exit-code --name-only ${TARGET}...${HEAD} {module}") == 1;
}

连同，即：

when { expression { return sourceChanged("A/") } }

检查多个目录中的差异将以这样的方式完成：

def SOURCE_DIRS = [
    "A/",
    "X/"
];
...
when { expression { return sourceChanged(SOURCE_DIRS) } }
...
def sourceChanged(ArrayList<String> source_dirs) {
    def target_branch = env.CHANGE_TARGET;
    def pr_ref        = env.BRANCH_NAME;

    if (target_branch == null) {
        echo "No target branch defined...";
        return true;
    }

    def TARGET = sh(returnStdout: true, script: "git rev-parse upstream/${target_branch}").trim()
    def HEAD   = sh(returnStdout: true, script: "git rev-parse origin/${pr_ref}").trim()

    echo "Checking for source changes between ${TARGET} (${target_branch}) and ${HEAD} (${pr_ref})...";
    for (String dir : source_dirs) {
        def rc = sh(returnStatus: true, script: "git diff --name-only --exit-code ${TARGET}...${HEAD} ${dir}");
        if (rc == 1) {
            echo "Changes detected in ${dir}!";
            return true;
        }
    }

    echo "No changes detected.";
    return false;
}

Answer 2

您还可以使用Configuration > Branch Sources > Behaviours为您的多分支项目指定额外的重新规范。Add > Specify ref specs，这将使您需要的任何分支名称都可用。

屏幕截图见此答案：https://stackoverflow.com/a/63267947/64505