jenkins - Jenkins 管道可以有一个可选的输入步骤吗？

Question

是否可以创建具有可选输入阶段的 Jenkins 管道？

下面的代码片段没有达到这个目标。

预期行为

阶段(以及输入提示)应该只针对特定的分支运行。

实际行为

此阶段适用于所有分支。使用输入步骤时，将忽略 when 过滤器。

stage('Approve') {
            when {
                expression { BRANCH_NAME ==~ /^qa[\w-_]*$/ }
            }
            input {
                message "Approve release?"
                ok "y"
                submitter "admin"
                parameters {
                    string(name: 'IS_APPROVED', defaultValue: 'y', description: 'Deploy to master?')
                }
            }
            steps {
                script {
                    if (IS_APPROVED != 'y') {
                        currentBuild.result = "ABORTED"
                        error "User cancelled"
                    }
                }
            }
        }

Answer 1

过滤器不会被忽略，它只是在输入步骤之后进行评估。在您的示例中，总是会询问您是否要部署，如果您不在 QA 分支上，则不会发生任何事情。

现在您可能会问为什么 Jenkins 不首先评估 'when' 指令。在这种情况下，您不能在 when 条件中使用输入参数。

并且拥有多个 when 指令就像在声明性管道中编写脚本一样。

但是，有一个表达式允许您控制何时计算 'when' 指令。这是 beforeAgent .它允许您在分配代理之前评估 when 语句。与此类似，您需要类似 beforeInput 之类的东西。您可以 create a feature request为了那个原因。

我不再使用 input 指令，而是现在在脚本块中使用 input，因为这提供了更大的灵活性，例如当有人必须批准某事时，我会发送 Slack 通知，这在声明式方法中是不可能的。为此，您需要一个通知指令。如果有，是在输入步骤之前还是之后进行评估？

你看，做所有声明性的事情并不总是最好的方式。所以我推荐的方法如下(免责声明:这是未经测试的!):

pipeline {
  // We want to use agents per stage to avoid blocking our build agents
  // while we are waiting for user input.
  agent none
  ...
  // The question mark naming convention is helpful to show you which
  //  approval stage belongs to which work stage.
  stage('Release?') {
    // Don't allocate an agent because we don't want to block our
    // slaves while waiting for user input.
    agent none
    when {
      // You forgot the 'env.' in your example above ;)
      expression { env.BRANCH_NAME ==~ /^qa[\w-_]*$/ }
    }
    options {
      // Optionally, let's add a timeout that we don't allow ancient
      // builds to be released.
      timeout time: 14, unit: 'DAYS' 
    }
    steps {
      // Optionally, send some notifications to the approver before
      // asking for input. You can't do that with the input directive
      // without using an extra stage.
      slackSend ...

      // The input statement has to go to a script block because we
      // want to assign the result to an environment variable. As we 
      // want to stay as declarative as possible, we put noting but
      // this into the script block.
      script {
        // Assign the 'DO_RELEASE' environment variable that is going
        //  to be used in the next stage.
        env.DO_RELEASE = input ...
      }
      // In case you approved multiple pipeline runs in parallel, this
      // milestone would kill the older runs and prevent deploying
      // older releases over newer ones.
      milestone 1
    }
  }
  stage('Release') {
    // We need a real agent, because we want to do some real work.
    agent any
    when {
      // Evaluate the 'when' directive before allocating the agent.
      beforeAgent true
      // Only execute the step when the release has been approved.
      environment name: 'DO_RELEASE', value: 'yes'
    }
    steps {
      // Make sure that only one release can happen at a time.
      lock('release') {
        // As using the first milestone only would introduce a race 
        // condition (assume that the older build would enter the 
        // milestone first, but the lock second) and Jenkins does
        // not support inter-stage locks yet, we need a second 
        // milestone to make sure that older builds don't overwrite
        // newer ones.
        milestone 2

        // Now do the actual work here.
        ...
      }
    }
  }