how to get the trigger information in Jenkins programmatically

Question

I need to add the next build time scheduled in a build email notification after a build in Jenkins.

The trigger can be "Build periodically" or "Poll SCM", or anything with schedule time.

I know the trigger info is in the config.xml file e.g.

<triggers>
    <hudson.triggers.SCMTrigger>
      <spec>8 */2 * * 1-5</spec>
      <ignorePostCommitHooks>false</ignorePostCommitHooks>
    </hudson.triggers.SCMTrigger>
  </triggers>

and I also know how to get the trigger type and spec with custom scripting from the config.xml file, and calculate the next build time.

I wonder if Jenkins has the API to expose this information out-of-the-box. I have done the search, but not found anything.

Answer 1

I realise you probably no longer need help with this, but I just had to solve the same problem, so here is a script you can use in the Jenkins console to output all trigger configurations:

#!groovy

Jenkins.instance.getAllItems().each { it ->
  if (!(it instanceof jenkins.triggers.SCMTriggerItem)) {
    return
  }

  def itTrigger = (jenkins.triggers.SCMTriggerItem)it
  def triggers = itTrigger.getSCMTrigger()

  println("Job ${it.name}:")

  triggers.each { t->
    println("\t${t.getSpec()}")
    println("\t${t.isIgnorePostCommitHooks()}")
  }
}

This will output all your jobs that use SCM configuration, along with their specification (cron-like expression regarding when to run) and whether post-commit hooks are set to be ignored.

You can modify this script to get the data as JSON like this:

#!groovy
import groovy.json.*

def result = [:]

Jenkins.instance.getAllItems().each { it ->
  if (!(it instanceof jenkins.triggers.SCMTriggerItem)) {
    return
  }

  def itTrigger = (jenkins.triggers.SCMTriggerItem)it
  def triggers = itTrigger.getSCMTrigger()

  triggers.each { t->
    def builder = new JsonBuilder()
    result[it.name] = builder {
      spec "${t.getSpec()}"
      ignorePostCommitHooks "${t.isIgnorePostCommitHooks()}"
    }
  }
}

return new JsonBuilder(result).toPrettyString()

And then you can use the Jenkins Script Console web API to get this from an HTTP client.

For example, in curl, you can do this by saving your script as a text file and then running:

curl --data-urlencode "script=$(<./script.groovy)" <YOUR SERVER>/scriptText

If Jenkins is using basic authentication, you can supply that with the -u <USERNAME>:<PASSWORD> argument.

Ultimately, the request will result in something like this:

{
    "Build Project 1": {
        "spec": "H/30 * * * *",
        "ignorePostCommitHooks": "false"
    },
    "Test Something": {
        "spec": "@hourly",
        "ignorePostCommitHooks": "false"
    },
    "Deploy ABC": {
        "spec": "H/20 * * * *",
        "ignorePostCommitHooks": "false"
    }
}

You should be able to tailor these examples to fit your specific use case. It seems you won't need to access this remotely but just from a job, but I also included the remoting part as it might come in handy for someone else.