Jenkinsfile - Jenkins 構建用戶 getUserName() NullPointerException：無法在 null object 上調用方法 getUserName() 多分支索引掃描

Question

Jenkins 2.138.1.2-rolling --and-- 使用MultiBranch Pipeline （從主、分支和拉取請求等構建構建）。

我想顯示在構建描述中啟動構建的 Jenkins 構建作業的用戶。

前任：

為了實現相同的功能，在我的Jenkinsfile中，我在頂部有以下代碼：

@NonCPS
def getBuildUser() {
    def build = currentBuild.rawBuild
    def cause = build.getCause(hudson.model.Cause.UserIdCause.class)
    def BUILD_USER = cause.getUserName()
    
    return BUILD_USER
}

pipeline {
    ...
}

Class 定義： https://javadoc.jenkins-ci.org/hudson/model/Cause.UserIdCause.html顯示該方法在類中未棄用。

在 Jenkinsfile 的階段部分下，我有以下代碼，它成功地實現了這一點。

stages {
   stage ('Start') {
       steps {
           script {
                   // Set Build Description
                   def BUILD_USER= getBuildUser()
                   currentBuild.description = "${BUILD_USER}: ${RELEASE_TAG} => ${DOCKER_IMAGES}"
           }

           sh '''
                 set +x
                 echo -e "\n\n-- Starting build process.\n"
              '''
       }
   }
   .. more stages are here ..
 }

當我使用多分支管道作業時，我看到了所有分支/PR，包括 master，在側邊欄上，我看到了以下鏈接：

多分支掃描周期設置為每10分鍾一次。

我看到有時構建失敗並出現以下錯誤，即java.lang.NullPointerException: Cannot invoke method getUserName() on null object

[Bitbucket] Build result notified
java.lang.NullPointerException: Cannot invoke method getUserName() on null object
    at org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:91)
    at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:48)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
    at org.codehaus.groovy.runtime.callsite.NullCallSite.call(NullCallSite.java:35)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
    at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:158)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:160)
    at org.kohsuke.groovy.sandbox.impl.Checker$checkedCall$1.callStatic(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallStatic(CallSiteArray.java:56)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callStatic(AbstractCallSite.java:194)
    at WorkflowScript.getBuildUser(WorkflowScript:5)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1213)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1022)
    at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:42)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
    at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:158)
    at org.kohsuke.groovy.sandbox.GroovyInterceptor.onMethodCall(GroovyInterceptor.java:23)
    at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:157)
    at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:156)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:160)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:125)
    at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:130)
    at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.methodCall(SandboxInvoker.java:17)
    at WorkflowScript.run(WorkflowScript:75)
    at ___cps.transform___(Native Method)
    at com.cloudbees.groovy.cps.impl.ContinuationGroup.methodCall(ContinuationGroup.java:57)
    at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.dispatchOrArg(FunctionCallBlock.java:109)
    at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.fixName(FunctionCallBlock.java:77)
    at sun.reflect.GeneratedMethodAccessor333.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.cloudbees.groovy.cps.impl.ContinuationPtr$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:122)
    at org.codehaus.groovy.runtime.GroovyCategorySupport.use(GroovyCategorySupport.java:261)
    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:174)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:347)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$200(CpsThreadGroup.java:93)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:259)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:247)
    at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:64)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    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(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Finished: FAILURE

我注意到，僅當Multi-Branch Scanning / Branch Indexing在后台運行時才會發生這種情況，因為所有失敗的構建都在該構建號的控制台頁面中列出了以下內容。

對於帶有構建描述的成功構建和所有，上面的“ BRANCH INDEXING ”框是不可見的（針對成功的構建#）。

為什么我得到這個java.lang.NullPointerException: Cannot invoke method getUserName() on null object錯誤（當我正在掃描以避免構建失敗時）

PS ：要重新創建此問題，用戶只需單擊
Scan Multibranch Pipeline Now的側邊欄圖標/鏈接，這將導致構建失敗，控制台 output 顯示：

PS ：安裝一個新插件可能需要一些時間（1-2 周）/掃描/安全團隊的批准過程，所以我認為這不是一個選項，至少在獲得批准之前是這樣。 例如： https://plugins.jenkins.io/build-user-vars-plugin/

Answer 1

為了避免構建失敗，目前，我啟用了try並catch並設置 BUILD_USER 的值，如果getCause(...)將失敗...就像當有人點擊側欄鏈接Scan MultiBranch Pipeline Now ，然后控制台 output或 Jenkins未設置單擊該側邊欄鏈接以啟動構建的用戶（如果要構建任何更改）並將Branch Indexing顯示為 output 中的第一行（而不是顯示： Started by user <some name> (someUserID) )。

因此，以下將 BUILD_USER 設置為有意義的值，並且不會使構建失敗。

@NonCPS
def getBuildUser() {
        def build = currentBuild.rawBuild
        def BUILD_USER = "ToBeSet"

        try {
             def cause = build.getCause(hudson.model.Cause.UserIdCause.class)
             BUILD_USER = cause.getUserName()
        } catch(Exception ex) {
             println "\n\n-- Build caused by either Multi-Branch Pipeline Scanning -or- Timer i.e. not directly by a logged in user\n";
             BUILD_USER = "Multi_Branch_Scan_or_Timer"
        }

        return BUILD_USER
}

我仍然想知道是否有辦法，我們可以找到，點擊側邊欄鏈接（登錄用戶）的人會戳進去。