Question

My project takes in a version number (separated by ‘.’ or ‘_’). I tried writing a Groovy script that creates a Jenkins environment variable using only the first two of these numbers:

//Get the version parameter
def env = System.getenv()
def version = env['currentversion']
def m = version =~/\d{1,2}/
env = ['miniVersion':m[0].m[1]]

Am I doing this correctly? Can I even create a new environment variable? Is there a better solution to this?

Answer 1

Jenkins 1.x

The following groovy snippet should pass the version (as you’ve already supplied), and store it in the job’s variables as ‘miniVersion’.

import hudson.model.*
  
def env = System.getenv()
def version = env['currentversion']
def m = version =~/\d{1,2}/
def minVerVal = m[0]+"."+m[1]
  
def pa = new ParametersAction([
  new StringParameterValue("miniVersion", minVerVal)
])
  
// add variable to current job
Thread.currentThread().executable.addAction(pa)

The variable will then be accessible from other build steps. e.g.

echo miniVersion=%miniVersion%

Outputs:

miniVersion=12.34

I believe you’ll need to use the "System Groovy Script" (on the Master node only) as opposed to the "Groovy Plugin" – https://wiki.jenkins-ci.org/display/JENKINS/Groovy+plugin#Groovyplugin-GroovyScriptvsSystemGroovyScript

Jenkins 2.x

I believe the previous (Jenkins 1.x) behaviour stopped working because of this Security Advisory…

Solution (paraphrased from the Security Advisory)

It’s possible to restore the previous behaviour by setting the system property hudson.model.ParametersAction.keepUndefinedParameters to true. This is potentially very unsafe and intended as a short-term workaround only.

java -Dhudson.model.ParametersAction.keepUndefinedParameters=true -jar jenkins.war

To allow specific, known safe parameter names to be passed to builds, set the system property hudson.model.ParametersAction.safeParameters to a comma-separated list of safe parameter names.

e.g.

java -Dhudson.model.ParametersAction.safeParameters=miniVersion,FOO,BAR -jar jenkins.war

And in groovy these two lines should be written this way:

System.setProperty("hudson.model.ParametersAction.keepUndefinedParameters","true");
System.setProperty("hudson.model.ParametersAction.safeParameters","miniVersion,FOO,BAR");