Jenkins Pipeline Job with file parameter

Question

I\'m putting together a Jenkins pipeline job which will take a file parameter. I can trigger the job and point it at a file however I can\'t find where the file has ended up

Answer 1

I found a solution in the form of a global library here: https://bitbucket.org/janvrany/jenkins-27413-workaround-library/src/default/

It contains calls to inner methods of Jenkins which are deprecated (I guess). So I made my own version like this:

import hudson.FilePath
import hudson.model.ParametersAction
import hudson.model.FileParameterValue
import hudson.model.Executor

def call(String name, String fname = null) {
    def paramsAction = currentBuild.rawBuild.getAction(ParametersAction.class);

    if (paramsAction == null) {
        error "unstashParam: No file parameter named '${name}'"
    }

    for (param in paramsAction.getParameters()) {
        if (param.getName().equals(name)) {
            if (! param instanceof FileParameterValue) {
                error "unstashParam: not a file parameter: ${name}"
            }
            if (env['NODE_NAME'] == null) {
                error "unstashParam: no node in current context"
            }
            if (env['WORKSPACE'] == null) {
                error "unstashParam: no workspace in current context"
            }
            workspace = new FilePath(getComputer(env['NODE_NAME']), env['WORKSPACE'])
            filename = fname == null ? param.getOriginalFileName() : fname
            file = workspace.child(filename)
            file.copyFrom(param.getFile())
            return filename;
        }
    }
}


def getComputer(name){

    for(computer in Jenkins.getInstance().getComputers()){ 
        if(computer.getDisplayName() == name){
            return computer.getChannel()
        }
    }

    error "Cannot find computer for file parameter workaround"
}

You can insert it in a global library and then use it like:

library "file-workaround"

node {
    def file_in_workspace = unstashParam "myFile"
    sh "cat ${file_in_workspace}"
}

It's not pretty but it's working and as long as there is no official fix, it's my best shot.

Update
Turns out you might run into "No such file or directory". That's because nothing in the workaround triggers Jenkins to create the workspace directory. If that was triggered somewhere else in the pipeline good, otherwise you'll be scratching your head.
You might wanna throw a

touch "thisIsAFile"

in there

Answer 2

To handle an optional file parameter in pipeline (to handle the use case where no file should be accepted) you could use jenkinsci-unstashParam-library (add it in Jenkins>Manage Jenkins>Configure System>Global Pipeline Libraries https://github.com/janvrany/jenkinsci-unstashParam-library) with a try/catch in a script as this sample stage:

    stage('upload') {
            steps {
                // delete workspace
                cleanWs()

                // handle file parameters in pipeline (JENKINS-27413)
                script {

                    try {
                        // force workspace directory creation
                        sh "touch emptyFileToCreateWorkspace"

                        // https://stackoverflow.com/questions/59468464/fetching-uploaded-files-in-jenkins
                        def file_in_workspace = unstashParam 'MY_FILE.xlsx'

                        // https://unix.stackexchange.com/questions/125776/error-with-a-file-name-containing-parentheses
                        sh "mv '${file_in_workspace}' MY_FILE.xlsx"
                    }
                    catch (Exception e) {
                        echo e.getMessage()
                        echo "No file parameter, we will continue.."
                    }
                }
            }
        }