How to reset build number in jenkins?

I am using Jenkins and Gradle to build my java project.

Every time I build my project, I get a new build number on the Jenkins screen.

The following is my Jenkins build info:

Success > Console Output  #96 	03-Jan-2014 15:35:08	
Success > Console Output  #95 	03-Jan-2014 15:27:29	 
Failed > Console Output  #94 	03-Jan-2014 15:26:16	 
Failed > Console Output  #93 	03-Jan-2014 15:25:01	 
Failed > Console Output  #92 	03-Jan-2014 15:23:50	 
Success > Console Output  #91 	03-Jan-2014 12:42:32	
Success > Console Output  #90 	03-Jan-2014 12:02:45

I want to reset the Jenkins build number like:

Success > Console Output  #1 	03-Jan-2014 12:02:45

How can I reset the build number in Jenkins?

Can be easier done from groovy script console . Go to http://your-jenkins-server/script In script window enter:

item = Jenkins.instance.getItemByFullName("your-job-name-here")
//THIS WILL REMOVE ALL BUILD HISTORY
item.builds.each() { build ->
  build.delete()
}
item.updateNextBuildNumber(1)

From here

> Given your Hudson job is named FooBar, > > - rename FooBar to FooBar-Copy > - create a new job named FooBar, using 'Copy existing job' option, from FooBar-Copy > - delete FooBar-Copy

• First wipeout workspace and get rid of previous builds.
• On the server navigate to the job dir eg. 'var/lib/jenkins/jobs/myJob' delete the workspace & build dirs as well as any polling files, lastSuccessful, lastStable files etc. You should only have config.xml and lastBuildNumber.
• Shut down jenkins using something like service jenkins stop
• Edit the file called nextBuildNumber, inserting 1 instead of the current build number
• Start up jenkins again, service jenkins start
• Log into jenkins and go to your job and hit build. Should start building job#1

If you want set the next build number, there is plugin "NextBuildNumber" for that. But this will not work in your case because the build number you need, which is 1, is lesser than your current build number.

Here need to wipe out all the previous builds first. You can do this by running this simple script Go to -> Manage Jenkins -> Script console

// change this variable to match the name of the job whose builds you want to delete
def jobName = "Your Job Name"
def job = Jenkins.instance.getItem(jobName)
job.getBuilds().each { it.delete() }

Now you can set next build number to 1 and run the build. It will start with 1. :) Its that simple.

Update - Jenkins now has a Purge Job History plugin to get this done in easiest way. Checkout the page for more details - https://wiki.jenkins.io/display/JENKINS/Purge+Job+History+Plugin

To more generally reset your build number to N (where N is not necessarily 1):

• Delete any existing builds where buildNumber >= N.
• Edit Program Files (x86)/Jenkins/jobs/yourjob/nextBuildNumber. Set the number it contains to N.
• From Jenkins, select Manage Jenkins -> Reload Configuration from Disk.

Expanding on the accepted answer, here's how to do it for all projects at once:

Jenkins.instance.allItems.each() { 
  item -> item.builds.each() { 
    build -> build.delete()
  }
  item.updateNextBuildNumber(1)
}  

As an extention of @antweiss's excellent answer, we can actually go further ...

There's no need to delete the full Build History, if you don't want to, you can simply roll back time, to a prior point:

resetNumberTarget = 14
item = Jenkins.instance.getItemByFullName("Project Name [from project Dashboard]")
//println(item)

item.builds.each() { build ->
  //println(build)
  //println(build.number)
  
  if(build.number >= resetNumberTarget)
  {
    //println("About to Delete '" + build + "'")    
    build.delete()  
  }
}

item.updateNextBuildNumber(resetNumberTarget)

If you want a dummy run, to check what it's going to do, without actually doing it, simply comment out the build.delete() and item.updateNextBuildNumber(resetNumberTarget) lines and uncomment the various print commands.

---

Documentation: Details of these objects were hard to find, but I identified the following:

• item is a FreeStyleProject (or possibly, just any type of Abstract Project?)

• build appears to be a Run, thus exposing a number property and inheritting a delete() method from Job

Use Purge Job History plugin (Jenkins >= 2.176.1)

https://plugins.jenkins.io/purge-job-history/

You can use either nexBuildNumber plug-in or simply modify nexBuildNumber file to reset build number. Following are the steps that you need to perform:

• Go to .jenkins/Jobs/<YourJobName>/build/, take backup of this folder(if you need for future use) and delete build folder.

> Note: Once you clean up old builds, you lose build histories and they > are no longer available on the Jenkins dashboard.

• Reload the configuration(Jenkins -> Manage Jenkins).
• Set next build version to 1 by either using the Next Build Number plug-in or modifying the nextBuildNumber file in yourjob directory.

So I tried the above solution and getting the following error.,

> groovy.lang.MissingPropertyException: No such property: builds for > class: > org.jenkinsci.plugins.workflow.multibranch.WorkflowMultiBranchProject.

So I tried this,

item = Jenkins.get().getItem("Job Name")
jobs = item.getAllJobs()
jobs.each() { item -> 
  builds = item.getBuilds()
  builds.each() { b -> 
    b.delete()
  }
  item.updateNextBuildNumber(1)

}

and it worked!!

I found an easy way to do this.

1. Wipe out your work space.
2. Go to each builds which saved on Jenkins and delete it.
3. Set build number to 1 then build.

Jenkins use previous build to determine the next build number, if build number you input is lower than previous build number, Jenkins will automatically increase your build number to higher than previous build. So here we just

To reset build numbers of all jobs:

Jenkins.instance.getAllItems(AbstractProject.class).each {
    item = Jenkins.instance.getItemByFullName(it.fullName)
    //THIS WILL REMOVE ALL BUILD HISTORY
    item.builds.each() { build ->
        build.delete()
    }
    item.updateNextBuildNumber(1)
}