simple build (DSL) for pipeline plugin

[Michael Neale]

Hey I thought some may be interested in this Pipeline DSL enhancement (ie a plugin that enhances Jenkins pipeline) which is installable as a plugin: https://wiki.jenkins-ci.org/display/JENKINS/Simple+Build+For+Pipeline+Plugin - interested in thoughts/feedback (you use it where you would use a Jenkinsfile or pipeline script). 

[Martin d'Anjou]

Hi Michael,

I played with the plugin quite a bit. I am very enthusiastic about this plugin, because it gives me a way to manage the pipeline script development as if it were a regular plugin (code, test, version and release), while being much easier to write than a regular plugin.

I do not plan to use the mini simpleBuild DSL as is, but I plan to use its base class PipelineDSLGlobal and build a different core with it. I do not plan on using the Jenkinsfile aspect yet, because I have multiple CD/CI pipelines per branch in my projects, and only one Jenkinsfile is supported currently.

One thing I was trying to do was to acess the "env" and the build parameters from inside the simpleBuild Closure. I changed "env" to "map" in the source (so "env" would not be hidden), and I attempted the following:

simpleBuild {
    ...
    map = [url: "http://host/path/${PARAM}/${env.BUILD_NUMBER}"]
    ...
}

I tried various ways of setting the closure delegate (see it on my github fork) but the alternative I tried results in not being able to resolve the "scm" in "checkout scm". If I use ${this.env.BUILD_NUMBER}, then it works, but I would feel more comfortable using your code if I understood why ${env.BUILD_NUMBER} cannot be resolved. The Closure owner is a WorkflowScript after all, and it should have "env".

Thanks,
Martin

[Michael Neale]

Hi Martin. 

Yes that is quite confusing. Well for one, I used the "env" to mean the key in a closure that ends up in config, which is slightly naughty, given there is already an env global - so probably shouldn't do what I did ;) 

I am not sure why it wouldn't work like that - if you use double quotes, then I think it would use string interpolation to expand it (perhaps there is a missing call to the token expander). 

checkout scm - that is for when it is multibranch - that will only work if you are running the job form a Jenkinsfile

[Martin d'Anjou]

Hi Michael,

I am still pretty happy about the simpleBuild method of writing Pipeline Plugins. It is very easy to extend from the PipelineDSLGlobal base class. I wrote some more code, and I can test my plugin on the command line (yay!) as well as with mvn hpi:run. But when I try to upload my plugin to a standalone Jenkins installation the upload center gives me this error:

java.io.IOException: Failed to dynamically deploy this plugin
  at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:1383)
  at hudson.model.UpdateCenter$DownloadJob.run(UpdateCenter.java:1161)
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
  at java.util.concurrent.FutureTask.run(FutureTask.java:262)
  at hudson.remoting.AtmostOneThreadExecutor$Worker.run(AtmostOneThreadExecutor.java:110)
  at java.lang.Thread.run(Thread.java:744)
Caused by: java.io.IOException: Failed to install simple-build-extension plugin
  at hudson.PluginManager.dynamicLoad(PluginManager.java:487)
  at hudson.model.UpdateCenter$InstallationJob._run(UpdateCenter.java:1379)
  ... 5 more
Caused by: java.io.IOException: Dependency simple-build-for-pipeline (0.2) doesn't exist
  at hudson.PluginWrapper.resolvePluginDependencies(PluginWrapper.java:533)
  at hudson.PluginManager.dynamicLoad(PluginManager.java:477)
  ... 6 more

My pom.xml appears to have the relevant bits:

    <repositories>
        <repository>
            <id>repo.jenkins-ci.org</id>
            <url>http://repo.jenkins-ci.org/public/</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>repo.jenkins-ci.org</id>
            <url>http://repo.jenkins-ci.org/public/</url>
        </pluginRepository>
    </pluginRepositories>

    <dependencies>
        <dependency>
            <groupId>org.jenkins-ci.plugins</groupId>
            <artifactId>simple-build-for-pipeline</artifactId>
            <version>0.2</version>
        </dependency>
...

Do you know what's missing, why Jenkins can't load a plugin that extends from simple-build-for-pipeline?

Thanks,
Martin

[Martin d'Anjou]

I will reply to my own question: plugins uploaded manually do not fetch their dependencies.

[Michael Neale]

Yes - interestingly that question/answer comes up a lot. Yes, you have to install deps yourself if using Advanced "tab" to install it. 

If you use mvn hpi:run to run it in development you don't need to worry about it (which is why few come across this). 

If this bites you enough, might I suggest opening an issue to see if there is interest in having an option to automatically install deps of an uploaded plugin (that are missing) if it can? 

[Martin d'Anjou]

I have written enough code to occasionally get a serialization error:

Apr 04, 2016 8:22:44 AM org.jenkinsci.plugins.workflow.cps.CpsThreadGroup saveProgram WARNING: program state save failed java.io.NotSerializableException: org.codehaus.groovy.runtime.HandleMetaClass

Do you know how I can test serialization of the whole "def call(body) { ... }" code and everything it contains (imports, etc.)?

Thanks,
Martin

[Michael Neale]

Good question, no not sure off the top of my head. I know Jesse identified a problem recently with checkpoints (and unrelated feature, but touches on save program I believe).