Jenkins – how can I know whether the plugin is used by any jobs in jenkins

Jenkinsjenkins-plugins

Jenkins had 600+ plugins, in the real system, we are used to install lots of plugins.

And sometimes, we want to remove some plugins to make system more clean or replace with another mature plugin (different name).

This needs to make sure no one/no job use those plugins or I need to notify them.

Are there any ways in configuration or somewhere in Jenkins system to know whether the plugin is used by any jobs ?

UPDATE 2013
Based on the answer below, I maintain the simple "plugin:keyword" mapping, like

plugin_keys = {
    "git":'scm class="hudson.plugins.git.GitSCM"',
    "copyartifact":"hudson.plugins.copyartifact.CopyArtifact",
        # and more      
}

And search the plugin keyword from the config.xml, all the information (plugins,jobs,config) can be fetched via jenkins remote API

it works for me.

UPDATE 2014.04.26
Later jenkins version, it seems the config.xml is changed to have plugin name there directly

<com.coravy.hudson.plugins.github.GithubProjectProperty plugin="github@1.4">
<hudson.plugins.throttleconcurrents.ThrottleJobProperty plugin="throttle-concurrents@1.7.2">
<hudson.plugins.disk__usage.DiskUsageProperty plugin="disk-usage@0.18"/>
<scm class="hudson.plugins.git.GitSCM" plugin="git@1.4.1-SNAPSHOT">

Therefore I just check this plugin="<plugin name>" in config.xml, it works again

UPDATE 2014.05.05

See complete script in gist jenkins-stats.py

UPDATE 2018.6.7

There is plugin usage plugin support this (no REST API yet)

Best Answer

Here are 2 ways to find that information.

The easiest is probably to to grep the job config files:

E.g. when you know the class name (or package name) of your plugin (e.g. org.jenkinsci.plugins.unity3d.Unity3dBuilder):

find $JENKINS_HOME/jobs/ -name config.xml -maxdepth 2 | xargs grep Unity3dBuilder

Another is to use something like the scriptler plugin, but then you need more information about where the plugin is used in the build.

import hudson.model.*
import hudson.maven.*
import hudson.tasks.*

for(item in Hudson.instance.items) {
    //println("JOB : "+item.name);
    for (builder in item.builders){
      if (builder instanceof org.jenkinsci.plugins.unity3d.Unity3dBuilder) {
        println(">>" + item.name.padRight(50, " ") + "\t UNITY3D BUILDER with " + builder.unity3dName);
      }
    }
  }
}

Update: here's a small scriplet script that might ease you finding the relevant class names. It can certainly be improved:

import jenkins.model.*;
import hudson.ExtensionFinder;

List<ExtensionFinder> finders = Jenkins.instance.getExtensionList(ExtensionFinder.class);

for (finder in finders) {
  println(">>> " + finder);
  if (finder instanceof hudson.ExtensionFinder.GuiceFinder) {
    println(finder.annotations.size());
    for (key in finder.annotations.keySet()) {
       println(key);
    }
  } else if (finder instanceof ruby.RubyExtensionFinder) {
    println(finder.parsedPlugins.size());
    for (plugin in finder.parsedPlugins) {
      for (extension in plugin.extensions) {
        println("ruby wrapper for " + extension.instance.clazz);
      }
    }
  } else if (finder instanceof hudson.cli.declarative.CLIRegisterer) {
    println(finder.discover(Jenkins.instance));
    for (extension in finder.discover(Jenkins.instance)) {
      println("CLI wrapper for " + extension.instance.class);
      // not sure what to do with those      
    }
  } else {
    println("UNKNOWN FINDER TYPE"); 
  }
}

(inlined scriplet from my original listJenkinsExtensions submission to http://scriptlerweb.appspot.com which seems down)

Don't forget to backup!

Related Solutions

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By setting the schedule period to 15 13 * * * you tell Jenkins to schedule the build every day of every month of every year at the 15th minute of the 13th hour of the day.

Jenkins used a cron expression, and the different fields are:

MINUTES Minutes in one hour (0-59)
HOURS Hours in one day (0-23)
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DAYWEEK Day of the week (0-7) where 0 and 7 are sunday

If you want to schedule your build every 5 minutes, this will do the job : */5 * * * *

If you want to schedule your build every day at 8h00, this will do the job : 0 8 * * *

For the past few versions (2014), Jenkins have a new parameter, H (extract from the Jenkins code documentation):

To allow periodically scheduled tasks to produce even load on the system, the symbol H (for “hash”) should be used wherever possible.

For example, using 0 0 * * * for a dozen daily jobs will cause a large spike at midnight. In contrast, using H H * * * would still execute each job once a day, but not all at the same time, better using limited resources.

Note also that:

The H symbol can be thought of as a random value over a range, but it actually is a hash of the job name, not a random function, so that the value remains stable for any given project.

More example of using 'H'

Java – How to conditionally lock in Java

You can use Lock objects, ReentrantLock in particular should do the work. http://docs.oracle.com/javase/tutorial/essential/concurrency/newlocks.html

Or you can still solve the issue with synchronized blocks. The code from your question will look like:

myMethod (Bool useLock) {
    if (useLock) {
        synchronized (this) {
           criticalSection();
        }
    } else {
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    }
}

criticalSection() {
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}

Or if you want to guarantee the mutual exclusion among different instances of the class you should use other monitor object than this. For instance TheClassName.class or other explicitly defined static variable of that class.

Best Answer

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