How can I find out if current Jenkins build is first run of the day from trigger

Question

I have Jenkins jobs that trigger twice a day and I would like to know if the current build is the first cron trigger of the day or not and do some action.

My cron job is as below

 triggers {
    // regression --> 3:00GMT, 14:00GMT
    cron("00 3 * * 1-5 \n 00 14 * * 1-5")
}

Can I set some boolean param in my Jenkins file to check if it's the first trigger of the day?

Answer 1

The simplest option would be to check the build history. If the previous build was executed on the previous day, then the current build is the first build of the day. The logic must be defined in the executed job configurations.

The currentBuild object is an instance of the org.jenkinsci.plugins.workflow.support.steps.build.RunWrapper class which provides all necessary information.

steps {
    echo "The first build of the day started by trigger: ${isFirstBuildOfDayStartedByTrigger(currentBuild)}"
}

// ...

boolean isFirstBuildOfDayStartedByTrigger(currentBuild) {
    if (isStartedByTrigger(currentBuild)) {
        return false
    }
    def today = toLocalDate(currentBuild.startTimeInMillis)
    def build = currentBuild.previousBuild
    while(build != null) {
        if (toLocalDate(build.startTimeInMillis).isBefore(today)) {
            return true
        }
        if (isStartedByTrigger(build)) {
            return false
        }
        build = build.previousBuild  
    }
    return true
}

LocalDate toLocalDate(long millis) {
    return Instant.ofEpochMilli(millis).atZone(ZoneId.systemDefault()).toLocalDate()
}

boolean isStartedByTrigger(build) {
    // TODO: use build.buildCauses or build.getBuildCauses('cause.class.Name')
    // to analyze if the job was started by trigger
    return true // or false
}

You have to figure out which build cause is added when the job is started by trigger.

If you just want to find the first build of the day executed by anything or anyone, then the code is much simpler:

steps {
    echo "The first build of the day: ${isFirstBuildOfDay(currentBuild)}"
}

boolean isFirstBuildOfDay(currentBuild) {
    def today = toLocalDate(currentBuild.startTimeInMillis)
    def previousBuild = currentBuild.previousBuild
    return previousBuild == null || toLocalDate(previousBuild.startTimeInMillis).isBefore(today)
}

LocalDate toLocalDate(long millis) {
    return Instant.ofEpochMilli(millis).atZone(ZoneId.systemDefault()).toLocalDate()
}

I used the new date API which I think is not whitelisted, so you have to put that code to the Jenkins library or approve the used method signatures.