Jenkins Pipeline: How do I use the sh module when traversing a map?

Question

My jenkins pipeline content is :

pipeline {
    agent any
    stages {
        stage('Example Build') {
            steps {
                script {
                    repos = [
                        'a': '1',
                        'b': '2',
                        'c': '3']
                    for (i in repos) {
                        echo "${i.key}, ${i.value}"
                        sh "echo test"
                    }
                }
            }
        }
    }
}

And I got an error on build :

Caused: java.io.NotSerializableException: java.util.LinkedHashMap$Entry
    at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:926)
    at org.jboss.marshalling.river.BlockMarshaller.doWriteObject(BlockMarshaller.java:65)
    at org.jboss.marshalling.river.BlockMarshaller.writeObject(BlockMarshaller.java:56)
    at org.jboss.marshalling.MarshallerObjectOutputStream.writeObjectOverride(MarshallerObjectOutputStream.java:50)
    at org.jboss.marshalling.river.RiverObjectOutputStream.writeObjectOverride(RiverObjectOutputStream.java:179)
    at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:344)
    at java.util.HashMap.internalWriteEntries(HashMap.java:1793)
    at java.util.HashMap.writeObject(HashMap.java:1363)
    at sun.reflect.GeneratedMethodAccessor176.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.jboss.marshalling.reflect.JDKSpecific$SerMethods.callWriteObject(JDKSpecific.java:156)
    at org.jboss.marshalling.reflect.SerializableClass.callWriteObject(SerializableClass.java:191)
...
Finished: FAILURE

If repos is list, run ok.

I can't fix the error, Hopefully someone can answer that.

Thank you for your answer.

Code works for me, with and without Groovy sandbox. Which version of Jenkins are you using? — zett42, Mar 28 '20 at 11:18
We had this as well, but intermittently and not specifically in an iteration, and got rid of the error happening by selecting the "Do not allow concurrent builds" option in the project settings — traneHead, Mar 28 '20 at 11:33
Please refer https://stackoverflow.com/questions/42770775/how-to-define-and-iterate-over-map-in-jenkinsfile. It might help. — subhadeep dutta gupta, Mar 28 '20 at 19:13
I upgraded jenkins to ver. 2.222.1, but still return the same error. — jugggao, Mar 29 '20 at 13:56

daggett · Accepted Answer · 2020-03-29T15:40:23.043

3

try to replace for(i in repos){...} to repos.each{k,v-> ...}

repos.each{k,v->
    echo "${k}, ${v}"
    sh "echo test"
}

the problem with for(i in repos){...}:

This statement iterates through map entries. And each entry i has type of Map.Entry which is not serializable.

Pipeline tries to persist the status of all variables because each next pipenine command (echo, sh) could be theoretically executed on another jenkins node.

on other hand when using repos.each{k,v->...} you are iterating map with simple serializable values in your case.

edited Mar 29 '20 at 15:40

answered Mar 28 '20 at 13:22

daggett

26,404
3
40
56

I just started learning groovy, always looking for the same syntax as python: `for k,v in repos`. thank you for the anwer. – jugggao Mar 29 '20 at 13:59
It is not working in my case. Now I am getting `java.io.NotSerializableException: java.util.ArrayList$Itr` – Arun Aug 19 '20 at 15:49
this question was about exact case with HashMap objet. and not about ArrayList. better to ask own question. but before this - please read about `CPS` and `@NonCPS`: https://www.jenkins.io/doc/book/pipeline/cps-method-mismatches/#common-problems-and-solutions – daggett Aug 19 '20 at 16:33

score -1 · Answer 2 · answered Mar 28 '20 at 19:26

-1

Please try more latest version of Jenkins.

answered Mar 28 '20 at 19:26

subhadeep dutta gupta

203
2
10

I upgraded jenkins to ver. 2.222.1, but still return the same error. – jugggao Mar 29 '20 at 13:56

Jenkins Pipeline: How do I use the sh module when traversing a map?

2 Answers2

Linked