Get error reason in Jenkinsfile failure

Question

I have the following post failure section:

   post {
        failure {
            mail subject: "\u2639 ${env.JOB_NAME} (${env.BUILD_NUMBER}) has failed",
                    body: """Build ${env.BUILD_URL} is failing!
                          |Somebody should do something about that""",
                      to: "devel@example.com",
                 replyTo: "devel@example.com",
                    from: 'jenkins@example.com'
        }
    }

I would like to include the reasons why the build failed in the body of the error message.

How can I do that?

If not, is there a way to attach the build log file to the email?

Answer 1

I don't know of a way to retrieve the failure reason automatically out of thin air.

However, you can use "post{ failure {" blocks in each phase to capture at least the phase in which it failed into a environment variable (e.g. env.FAILURE_REASON), and access that env var in the final (global scope) notification block.

For more granularity, you can reuse the same mechanism of the global env variable, but use try { } catch { } blocks to capture which specific step failed.

A generic example would be:

   pipeline {
     stages {
       stage('Build') {
         steps {
           ...
         }
         post {
           failure {
             script { env.FAILURE_STAGE = 'Build' }
           }
         }
       }
       stage('Deploy') {
         steps {
           ...
         }
         post {
           failure {
             script { env.FAILURE_STAGE = 'Deploy' }
           }
         }
       }
       ...
     }
     post {
        failure {
            mail subject: "\u2639 ${env.JOB_NAME} (${env.BUILD_NUMBER}) has failed",
                    body: """Build ${env.BUILD_URL} is failing in ${env.FAILURE_STAGE} stage!
                          |Somebody should do something about that""",
                      to: "devel@example.com",
                 replyTo: "devel@example.com",
                    from: 'jenkins@example.com'
        }
      }
    }

Technically, you can even do some automated triage based on the failing stage and send a more targeted notification, or even create specific (e.g. Jira) tickets.

For attaching the console log to the email notification, you'd want to look at emailext and the 'attachLog: true' attribute