How to stop a build in Jenkins via the REST api ?

If the build has started, by POST on:

http://<Jenkins_URL>/job/<Job_Name>/<Build_Number>/stop

Will stop/cancel the current build.

If the build has not started, you have the queueItem, then POST on:

http://<Jenkins_URL>/queue/cancelItem?id=<queueItem>

This is assuming your Jenkins Server has not been secured, otherwise you need to add BASIC authentication for a user with Cancel privileges.

Actually this question is already answered. So I will add, how to find id=<queueItem> , which I got stuck on finding this solution, which will helpful for others.

So, you can get <queueItem>, by - http://jenkins:8081/queue/api/json

Sample Output will be of json type like this one -

[{"_class":"hudson.model.Cause$RemoteCause","shortDescription":"Started by remote host 172.18.0.2","addr":"172.18.0.2","note":null}]}],"blocked":false,"buildable":false,"id":117,"inQueueSince":16767552,"params":"\nakey\t=AKIQ\nskey=1bP0RuNkr19vGze/bcb4ijDqVr8o\nnameofr=us\noutputtype=json\noid=284102\nadminname=admin","stuck":false,"task"

You have to take "id":117, and parse it to - queueItem =117.

http://<Jenkins_URL>/queue/cancelItem?id=queueItem

Maybe you want to remotely send a post http request to stop a running build, there is a clue FYI, the jenkins job can stop another job(running build), like any jenkins admin click the X button when job is running.

1. Http Request Plugins is required by Jenkins ver2.17
2. Uncheck the Prevent Cross Site Request Forgery exploits option. Manager Jenkins -> Configure Global Security -> Uncheck
3. Setup Http Request Plugins's authorization. Manager Jenkins -> Configure System -> HTTP Request Basic/Digest Authentication -> add. Make sure the user has the job cancel permission
4. Job A is running. In job B, add build step as HTTP Request, URL: http://Jenkins_URL/job/Job_A_Name/lastBuild/stop, HTTP mode: POST, Authorization select the user you have just set, then build job B.

Done