Setting the Hudson/Jenkins next build number programatically

Programatically setting the next build number in Hudson/Jenkins is a useful thing to do if you have a build pipeline. After a bit of research it seems there are 3 main approaches that could be useful in different situations:

1. Set the nextBuildNumber.txt in your Hudson job's directory
2. Use environment variables for build number passthrough (see @ruby_gem's post here)
3. Use the nextBuildNumber Hudson plugin and HTTP POST the build number to it

In this post I'll be looking at option 3 - using the nextBuildNumber Hudson plugin.

Using the nextBuildNumber Hudson plugin

Firstly install the nextBuildNumber plugin. You can now set the next build number for a job manually from the plugin link that appear on the left.
To use this programatically you simulate the manual for submission with a web client. I tested it with FireFox ReST client.
To set the next build number to 999 simply formulate an HTTP POST to your Hudson URL:

e.g. http://myhudsonserver:8080/job/myhudsonjobname/nextbuildnumber/submit

With the form data

nextBuildNumber=999

And the HTTP Content-Type request header

Content-Type: application/x-www-form-urlencoded

If your Hudson is secured you'll need to authenticate your web client too.

That's it! Finally it's worth noting that build numbers in Hudson can only go up!