conferences | Anthony Dahanne's blog

While working on my talk Writing a Hudson / Jenkins plugin (for EclipseCon NA 2014), I wanted to publish blog posts about the ideas mentioned in the talk; in this post I explain how you can interact with your CI server without using the web interface.

The Jenkins / Hudson remote API can be very convenient to quickly gather jobs status (and even to create or launch jobs ! but I won’t cover that aspect in this blog post); let’s have a look at some examples.

Have a look at the CLI to automate Jenkins configuration tasks.

It’s available at http://hudson-or-jenkins/cli : download the hudson-cli.jar or jenkins-cli.jar and get started with this first command :

1	$ java -jar jenkins-cli.jar -s http://jenkins.terracotta.eur.ad.sag:8080/ help

Recently, I had to replace 50 jobs with a matrix job : once I created the matrix job, we decided to de activate the previous 50 jobs (before removing them for good)

Using the CLI, I could quickly login :

1	$ java -jar jenkins-cli.jar -s http://jenkins.xx:8080/ login --username anthony --password password

then get the list of jobs :

1	$ java -jar jenkins-cli.jar -s http://jenkins.xx:8080/ list-jobs

I saved the list of the 50 jobs I wanted to de activate in a text file, and I looped through this list :

1	$ while read p; do java -jar jenkins-cli.jar -s http://jenkins.xx:8080/ disable-job $p; done < list_of_jobs.txt

More efficient than going through the UI, isn’t it ?

Every URL can be represented as XML or JSON

As explained in the Jenkins documentation and Hudson documentation, you just need to append /api/xml or /api/json or /api/python to any Jenkins URL to see the corresponding representation

You can configure the responses adding few arguments to the URL :

Depth

The default depth is 0, to get more details about your jobs, builds, etc, set the depth to 1 :

http://ci.jruby.org/api/xml?depth=1

This argument can be harmful to your CI server when bigger than 1 (it gets really deep past 1 …) since the responses tend to become really large.

Tree

The tree argument allows you to select some portion of the response

http://ci.jruby.org/api/xml?depth=1&tree=jobs[displayName,lastBuild[result]]

xpath and exclude (XML only)

Those arguments are probably the most powerful ones, sadly they are only available for xml responses :

If I only want to display jobs that were not successful, I can simply use this url :

http://ci.jruby.org/api/xml?depth=1&tree=jobs[displayName,lastBuild[result]]&exclude=hudson/job[lastBuild[result=’SUCCESS’]]

And if I only want to see jobs with a name starting with « jruby », I can apply Xpath functions to the url :

http://ci.jruby.org/api/xml?xpath=hudson/job[starts-with(name,’jruby’)]&wrapper=mywrap

Few Jenkins and Hudson public instances URLs

It’s pretty easy to find some public Jenkins and Hudson instances to practice your latest URL filtering (google for « Hudson Dashboard » or « Jenkins Dashboard »), but it’s harder to find up to date and meaningful (few jobs) instances :

Jenkins :

Hudson :

That said, try your local instance first

Jenkins and Hudson remote API scripts

The main interest of the Jenkins/Hudson remote API is to interact with it from your own software : I gather here some examples in few scripting languages

Groovy Script to parse Jenkins Hudson build results

class BuildParser {

static void main(String[] args) {

if (args.length != 1) {

println("Please run the script with a Jenkins or Hudson url as the only argument\n Example : groovy BuildParser.groovy http://ci.jruby.org");

return;

}

def url = args[0];

def xmlInputFilteringSuccess = new XmlParser().parse(url + "/api/xml?depth=1&tree=jobs[displayName,lastBuild[result]]&exclude=hudson/job[lastBuild[result=%27SUCCESS%27]]");

def xmlInputNoFilter = new XmlParser().parse(url + "/api/xml?depth=1&tree=jobs");

def jobs = xmlInputFilteringSuccess.job;

println(jobs.size() + " jobs out of " + xmlInputNoFilter.job.size() + " are currently failing")

jobs.each(

{

println(

it.displayName.text() +

" result is " + it.lastBuild.result.text())

}

)

}

Python Script to parse Jenkins Hudson build results

import ast

import urllib

import sys

if len(sys.argv) != 2:

print "Please run the script with a Jenkins or Hudson url as the only argument\n Example : python BuildParser.py http://ci.jruby.org"

sys.exit(1)

url = str(sys.argv[1])

print url

xml_input_no_filter = ast.literal_eval(urllib.urlopen(url + "/api/python?depth=1&tree=jobs[displayName,lastBuild[result]]").read())

all_jobs = xml_input_no_filter['jobs']

non_successful_jobs = [row for row in all_jobs if 'SUCCESS' != row['lastBuild']['result']]

print(str(len(non_successful_jobs)) + " jobs out of " + str(len(all_jobs)) + " are currently failing")

for (i, item) in enumerate(non_successful_jobs):

print "Job name : " + item['displayName'] + "Result : " + item['lastBuild']['result']

JavaScript code to parse Jenkins Hudson build results

<title>Build Parser</title>

$(document).ready(function(){

var baseUrl;

$('button').click(function(){

baseUrl = $("#baseUrl").val();

$("#jobUrl").html(baseUrl)

var success = function(json) {

var allJobs = json["jobs"];

var nonSuccessfulJobs = allJobs.filter(function( job ) {

return job["lastBuild"] != null && job["lastBuild"]["result"] != "SUCCESS";

});

$("#downstream").html(nonSuccessfulJobs.length + " out of " + allJobs.length + " are currently failing");

$.each(nonSuccessfulJobs, function( index, value ) {

$("#downstream").append("<br />Job name : " + value["displayName"] + " : "+ value["lastBuild"]["result"] );

});

};

$.ajax({

url: baseUrl + "/api/json",

data: "depth=1&tree=jobs[displayName,lastBuild[result]]&jsonp=callBack",

jsonpCallback: "callBack",

dataType: 'jsonp',

success: success

});

</script>

</head>

<h3>Input Data</h3>

Hudson/Jenkins Base URL:

<button>update</button><br />

<h2>Output</h2>

<h3>Failing Jobs</h3>

</div>

</body></html>

You can find those scripts on Github ! Or even execute them in your browser for the Javascript Jenkins Hudson Build parser script

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Using Jenkins / Hudson remote API to check jobs status