Why does Jenkins pipeline allows duplicate parameters? - jenkins

In Jenkins pipeline, one can create parameter with same name twice or more(also with same type).
Let's say I've a String Parameter with name Branch and again I can create String Parameter with same name i.e. Branch. It is duplicated still I can save the pipeline.
If you access that parameter in pipeline, while both have been assigned values during trigger, value of latest parameter(i.e second defined parameter) is taken into consideration.
What is reason of Jenkins allows duplicate parameter? Is there any valid reason/use case for this? Or any technical challenges? Or known bug open?
NOTE Jenkins version I'm using is 2.205

Related

Jenkins Addon in Jenkins Pipeline

I have a parameterized project. With the variable VAR1.
I'm using the the Xray for JIRA Jenkins Plugin for Jenkins. There you can fill four parameters:
JIRA Instance
Issues
Filter
File Path
I'm new to Jenkins but what I have learned so far, that you can't fill this fields with environment variables. Something like
Issues: ${VAR1} - doesn't work.
So I thought I can do this with a pipeline. When I click on Pipeline Syntax and chose step: General Build Step I can choose Xray: Cucumber Features Export Task. Then I fill the fields with my environment variable and click Generate Pipeline Script The output is as follows:
step <object of type com.xpandit.plugins.xrayjenkins.task.XrayExportBuilder>
That doesn't work. What I'm doing wrong?
All you're doing is OK, but what you want is not supported by Jenkins whether it is pipeline or not, since the parameters' load is happening prior to the pipeline-flow or the definition of the ${VAR1}.
You can try to overcome this by defining the 'Issues' value as a pipeline internal value instead of a parameter and base it on the ${VAR1} value.
If it must be a parameter, use 2 jobs where one defines the value of 'Issues' based on a the ${VAR1} and pass it to the other job that gets the 'Issues' as a fixed value.

Trigger Jenkins Job for every parameter

I have created a Global choice Parameter using Extensible Choice Parameter plugin.
I am using this parameter list in one of my parametrized jenkins job.
Is there a way in jenkins, where I can execute the job with each of the parameters in the Global choice Parameter list?
I have had a look on Build Flow job in jenkins, as suggested in this answer, but it seems it accepts hardcoded parameters only, and not dynamic.
I finally managed to resolve this using the following steps (with great help from this post) -
As my parameters list is dynamic in nature, it could be added or modified according to other jobs, we have managed it in a text file.
Next, We have used Extensible Choice Parameter plugin to display the parameters, using the groovy script -
def list = [];
File file = new File("D:/JenkinJob/parameterList.txt")
file.eachLine { line ->
list.add("$line")
}
return list
Now I want to call this jenkins job for each of the parameter.
For this, I have installed, BuildFlow plugin, and crated a new jenkins job of BuildFlow type -
Next, get the Extended Choice Parameter plugin, and configure it as follows -
Now in the flow step of this job, write this script, where "Feature" is the parameter, that is just created above, and within call to "build" parameter, pass in the name of job which we want to call for each parameter -
def features = params['Features'].split(',')
for (feature in features ) {
build("JobYouWantToCall", JobParameter: feature,)
}

How to pass info from one job to another

I have a jenkins job (jobA) which calls another one (jobB).
I have a string which is generated in a batch file called by jobA which needs to be passed into jobB.
How can I get that string out of jobA and into jobB?
Might it be possible to, say, set an environment variable to that string, somehow turn it into a jenkins parameter, and then pass that parameter into jobB?
Currently, my only other idea is to write the string out to a file in jobA, save that file as an artifact, pass that artifact into jobB, and then have jobB read that file. That seems a really kludgey way to do it, though.
It seems that there must be a better way.
One option is to use Jenkins Parameterized Trigger Plugin.
Then, you can for example set jobB's parameters based on a properties file generated by jobA.

Jenkins- Post Build Task: access the parameterized value of the job

I have Job on Jenkins ver. 1.500 with build ID parameterized.
I want to use this parameterized value in the subject line of section "Post-build Actions".
If I try to access using $ID or ${ID} its printing it as plane string "$ID"[without value substitution]. I am aware of environmental variable $BUILD_NUMBER, which is giving the current job #number.
Can someone share, how to achieve this simple task of reading build number?
$PROJECT_NAME - Job # $ID built at $BUILD_ID - $BUILD_STATUS!
--Thanks,Prashant
It sounds like you are talking about Editable Email Notification post-build action. It has it's own way of referencing variables.
Variables that are available within the plugin, can be referenced directly as ${VARIABLE}, in both the body of the email and the subject line. For a list of available variables, click on the ? icon for on-page help.
However to access other environmental variables, including the parameters used by the build, you have to use the format ${ENV, var="VARIABLE"}, so in your case, it would be ${ENV, var="ID"}

How to store last value of parameter in parameterized job as a default value for next build in Jenkins?

I have been using Jenkins for a few weeks and I have one small problem. I can't find any plugin or solution for storing the last value of a parameter in a parametrized job as a default value for the next build.
For example:
My parameter takes build version (1.0.0.01) in the first build. In the next build it will be changed to 1.0.0.02, but I want to have a 1.0.0.01 in the default value field as a hint.
Does anybody have a solution or advice?
The Persistent Parameter Plugin is exactly what you are looking for!
You just need to download it from the official Jenkins repository and install it, no need for any additional setup.
Then on your job, you just need to add a "Persistent Parameter" in order to have default values used and saved between builds.
You can add a System groovy build step to your job (or maybe a post build Groovy step) using the Jenkins API to directly modify the project setting the default parameter value.
Here is some code that may be useful to get you started:
import hudson.model.*
paramsDef = build.getParent().getProperty(ParametersDefinitionProperty.class)
if (paramsDef) {
paramsDef.parameterDefinitions.each{ param ->
if (param.name == 'FOO') {
println("Changing parameter ${param.name} default value was '${param.defaultValue}' to '${param.defaultValue} BAR'")
param.defaultValue = "${param.defaultValue} BAR"
}
}
}
Have a look at the class ParameterDefinition in the Jenkins model.
You probably need to modify the default param value based on the current build executing. Some code to get that would look like this:
def thisBuildParamValue = build.buildVariableResolver.resolve('FOO')
The Extended Choice Parameter plugin provides this capability by using default parameter values from a properties file. A default parameter can be selected from a specified property key and this key can be programmatically modified in your current build. I would then use a groovy script in the current build to set the value of the default property key for the next build.
As an example you would have an Extended Choice Parameter whose default value is defined by a properties file version.properties with keys as follows:
versions=1.0.0.02, 1.0.0.01, 1.0.0.00
default.version=1.0.0.02
The parameter definition would include:
Property File=version.properties
Property Key=versions
Default Property File=version.properties
Default Property Key=default.versions
The GUI for your parameter in the next build would show a selection list with 1.0.0.02 selected by default. This feature is also very useful for pipeline builds where you would want the parameters of a downstream build stage to be set by an earlier build.
The only drawback to this approach might be that the parameter UI will be a drop-down selection. You may opt to have a single value in the versions property key so not to confuse your users.
Similar to thiagolr's answer, but for those of you using pipelines! It appears the persistent-parameter-plugin doesn't work for those using pipeline 2.0. But there is a patched version at https://github.com/ashu16815/persistent-parameter-plugin which seems to work for me.
Clone it locally:
git clone https://github.com/ashu16815/persistent-parameter-plugin.git
Build it:
mvn clean install
Install it in Jenkins:
1) Navigate to Jenkins > Manage Jenkins > Manage Plugins
2) Click Advanced tab
3) Scroll down to Upload Plugin
4) Click Choose file and select the persistent-parameter.hpi in the target directory of the maven build above
Now it should persist.

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