Parsing an XML file within a Jenkins pipeline

Question

I have an XML file which I'd like to use as input for a pipeline script. Problem is the XMLParser isn't serializable so I put it in a NonCPS function, but I lost the Node object because of that.

This is the pipeline script:

def buildPlanPath = 'C:\\buildPlan_test.xml'

@NonCPS
groovy.util.Node getBuildPlan(path) {
    new XmlParser().parseText(readFile(path))
}

node {
    //def buildPlan = new XmlParser().parseText(readFile(buildPlanPath))
    groovy.util.Node buildPlan = getBuildPlan(buildPlanPath)

    println buildPlan.getClass()
    println buildPlan
    println buildPlan.branch
}

This is an input sample:

<branch name='mybranch'>
    <stage>
        <job name='job11' />
        <job name='job12' />
    </stage>
    <stage>
        <job name='job21' />
        <job name='job22' />
        <job name='job23' />
    </stage>
    <stage>
        <job name='job31' />
    </stage>
</branch>

This is the result:

Started by user admin
[Pipeline] node
Running on master in C:\Jenkins\workspace\pipeline-develop
[Pipeline] {
[Pipeline] readFile
[Pipeline] echo
class java.lang.String
[Pipeline] echo
<branch name='mybranch'>
  <stage>
    <job name='job11' />
    <job name='job12' />
  </stage>
  <stage>
    <job name='job21' />
    <job name='job22' />
    <job name='job23' />
  </stage>
  <stage>
    <job name='job31' />
  </stage>
</branch>
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
groovy.lang.MissingPropertyException: No such property: branch for class: java.lang.String
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:53)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.getProperty(ScriptBytecodeAdapter.java:458)
    at com.cloudbees.groovy.cps.sandbox.DefaultInvoker.getProperty(DefaultInvoker.java:25)
    at com.cloudbees.groovy.cps.impl.PropertyAccessBlock.rawGet(PropertyAccessBlock.java:17)
    at WorkflowScript.run(WorkflowScript:16)
    at ___cps.transform___(Native Method)
    at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.get(PropertyishBlock.java:62)
    at com.cloudbees.groovy.cps.LValueBlock$GetAdapter.receive(LValueBlock.java:30)
    at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.fixName(PropertyishBlock.java:54)
    at sun.reflect.GeneratedMethodAccessor327.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
    at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
    at com.cloudbees.groovy.cps.Next.step(Next.java:58)
    at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:154)
    at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:164)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:276)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$000(CpsThreadGroup.java:78)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:185)
    at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:183)
    at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:47)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:112)
    at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Finished: FAILURE

I'm using Jenkins 2.7 with pipeline 2.1, which are currently the latest.

Answer 1

In the end I think my approach was wrong: I decided to convert the XML file into a separate groovy script and load it within the pipeline

Update: Recently people started editing my answer for clarity, but the fact is that I just ditched storing my configuration in XML files and opted for groovy scripts, which gave me more flexibility. I understand it may not be a common practice, but it suits my needs.

For example - instead of:

config.xml:
<settings>
  <floopi>2</floopi>
</settings>

I used:

config.groovy:
def call() {[
  floopi: 2
]}
return this

And in the pipeline script:

stage('init') {
    def settings = load('config.groovy')()
    echo "floopi: ${settings.floopi}"
}

I hope that's a better answer :)

Answer 2

You could use XmlSlurper, it works for me.

def xmlText = new XmlSlurper().parse(MyURL)
xmlText.data.artifact.each {******

Answer 3

A @NonCPS method should only accept or return Serializable types. Try returning .branch from the method.

Answer 4

As branch is the root element, you don't need to explicitly specify it when accessing your parsed nodes

Try changing

println buildPlan.branch

To

println buildPlan.stage

To print out the stage nodes