Jenkins Update Center Generator
This project is primarily used to generate the jenkins.io update center layout.
With a few modifications it could easily be used to generate your corporate update center as well.
|This tool is optimized for use by the Jenkins project in Jenkins project infrastructure. Expect incompatible changes, like options not used by the Jenkins project being dropped. Additionally, this documentation is focused on how the tool is used by the Jenkins project, rather than the customizations necessary to create private update sites.|
See site layout for more detailed documentation on site structure.
The generator pulls information from:
Artifactory artifact repository (see
Artifactory API for listing artifacts
downloading artifact files
downloading individual files in archives such as
determine source code repository that actually exists (sometimes metadata is wrong)
plugin labels from repositories topics
default branch name
Jenkins usage statistics (see
latest plugin installation numbers for
popularityentries in update center JSON
Various metadata JSON files on
Plugin issue tracker metadata JSON file, see
Plugin maintainer mapping JSON file, see
Maintainer info JSON file, see
GitHub topic allowlist (
Standalone deprecations (
Artifact ignore list (with deprecation URLs) (
Label assignments (
Security warnings (
Plugin URL overrides (
Features Controlled Through Resource Files
Plugin labels are shown to users:
as categories in Jenkins before 2.224 and on the plugins site
as tags in Jenkins from 2.224 and also on the plugins site.
See this Jenkins resource file (look for
UpdateCenter.PluginCategory) for the localization overrides applied to labels by Jenkins.
Other labels are categorized into general Misc (custom-label-here) categories (Jenkins before 2.224) or displayed as is.
Two ways can be used to define these labels:
Add topics to your GitHub repository.
For a list of supported topics, see the resource file that contains all topics that can be set on GitHub repositories that will be reflected in update sites.
Topics can be set with or without the prefix
jenkins-. If a topics has that prefix, it is removed first:
To add the label
matrix for your plugin, you would add either
jenkins-matrix on your repository.
As an alternative to the above, plugin labels can be defined in the file
resources/label-definitions.properties in this repository.
This is the preferable approach when a plugin isn’t in the
jenkinsci GitHub organization, or a GitHub repository contains multiple plugins whose labels should be different.
Plugin URL Override
Plugins are generally expected to provide a
<url> to their documentation in their POM.
Historically, these URLs have been pages on the Jenkins wiki, but can point anywhere.
This requirement no longer exists, but it may still be useful to define a documentation URL for plugins that do not specify the correct URL.
resources/wiki-overrides.properties defines these wiki page overrides.
Any entries in this file are expected to be temporary, i.e. plugin maintainers are expected to fix their plugin’s metadata.
Plugins are considered deprecated by Jenkins when either the update site metadata does one or both of the following:
Uses the label
deprecatedfor the plugin. This can be done via GitHub repository topics, or the
resources/label-definitions.propertiesdescribed above. Jenkins will use the plugin URL as the reference URL for the deprecation notice.
Lists an entry with the plugin ID as key in the top-level
update-center.json. This can be done through entries in the
resources/deprecations.propertiesfile (for plugins that continue being distributed) or in
resources/artifact-ignores.propertiesfor plugins that are suspended. The value from the properties file will be used as the URL for the deprecation notice in Jenkins. This entry and URL take precedence over a
deprecatedlabel, i.e. when both are set, the URL from the top-level element shall be used.
These two different approaches to plugin deprecation accomplish complementary goals:
The label approach is very simple and can easily be done by plugin maintainers themselves via GitHub labels. It is also backward compatible with any earlier version of Jenkins — it will just show the deprecation as a regular label. Additionally, it doesn’t bloat the JSON file size at all, since no special URL is needed.
deprecationselement allows specifying a URL different from the plugin documentation URL as well as deprecating plugins no longer being distributed. Especially the latter is a common requirement when plugins integrate with services that no longer exist: It makes no sense to continue distributing them, but everyone having them already installed should be informed about it.
Removing plugins from distribution
The update center generator allows to specify that certain plugins, or plugin releases, should not be included in the output.
There are various reasons to need to do this, such as:
A plugin release causes major regressions and a fix is not immediately available.
A plugin integrates with a service that has been shut down.
Both use cases (entire plugins, or specific versions) are controlled via the file
That file may also define URL of a deprecation notice that is shown to users who already installed the plugin.
See that file for usage examples.
Since Jenkins 2.32.2 and 2.40, Jenkins can display security warnings about core and plugins.
These warnings are part of the update center metadata downloaded by Jenkins.
These warnings are defined in the file
mvn clean verify) the generator and then invoke it as follows:
java -Dfile.encoding=UTF-8 -jar target/update-center2-*-SNAPSHOT-bin/update-center2-*-SNAPSHOT.jar --id default ...
The tool also supports batch mode execution, generating multiple update sites with a single invocation:
java -Dfile.encoding=UTF-8 -jar target/update-center2-*-SNAPSHOT-bin/update-center2-*-SNAPSHOT.jar --arguments-file <filename.txt>
filename.txt is a text file with a list of arguments on each line.
Lines that start with
# are comments and ignored.
# one update site per line # Minimal update sites for Jenkins <= 2.204 and 2.204.x LTS --www-dir ./www2/2.204 --limit-plugin-core-dependency 2.204.999 --write-latest-core --www-dir ./www2/stable-2.204 --limit-plugin-core-dependency 2.204.999 --write-latest-core --only-stable-core # Minimal update sites for Jenkins <= 2.222 and 2.222.x LTS --www-dir ./www2/2.222 --limit-plugin-core-dependency 2.222.999 --write-latest-core --www-dir ./www2/stable-2.222 --limit-plugin-core-dependency 2.222.999 --write-latest-core --only-stable-core # Experimental (alpha/beta) update site, no version caps, collect files for download (including experimental files) --www-dir ./www2/experimental --with-experimental --downloads-directory ./download # Latest update site for Jenkins > 2.222, with release-history.json, plugin-versions.json, plugin-documentation-urls.json, collect files for download, and generate plugin count --generate-release-history --generate-plugin-versions --generate-plugin-documentation-urls --write-latest-core --write-plugin-count --www-dir ./www2/current --download-links-directory ./www2/download --downloads-directory ./download --latest-links-directory ./www2/current/latest
For a full list of arguments, invoke the tool as follows:
java -Dfile.encoding=UTF-8 -jar target/update-center2-*-SNAPSHOT-bin/update-center2-*-SNAPSHOT.jar --help
Preparing local execution
./site/generate.sh will first create the batch mode control file
./tmp/args.lst, before actually starting the tool.
The following steps are therefore useful when trying to generate output corresponding to the real update sites during development:
Implement changes in
./site/generate.shuntil the Java tool is actually launched, then abort. This requires some environment variables to be defined.
tmp/args.lst, changing or removing the
--root-certificatearguments as necessary.
java -Dfile.encoding=UTF-8 -jar target/update-center2-*-SNAPSHOT-bin/update-center2-*-SNAPSHOT.jar --arguments-file tmp/args.lst
Alternatively, the closest you can get to real executions in local development:
Implement changes in
Deploy a snapshot using
mvn deploy. Requires an account in the Jenkins project, see Deploying changes below.
site/generate.shto reference the specific snapshot you deployed (including timestamp) where it is downloaded using
wget, see previous build output.
Optionally, to speed things up, edit
site/generate.shand remove the arguments
--downloads-directory "$DOWNLOAD_ROOT_DIR"from some of the invocations.
./site/generate.sh <www-dir> <downloads-dir>. The first argument is the output directory for metadata, the second argument is the output directory for downloads and unused unless the previous step 4 was skipped.
Running within an IDE
The project various artifacts to be used on a site hosting a jenkins update center The project produces a jar and a zip file containing all the required dependencies to run the generator.
If you want to run the generator from within your development environment, you can try to use the appassembler plugin as described below. The exec:java plugin won’t work.
mvn package appassembler:assemble sh target/appassembler/bin/app --id default ...
./site/generate.sh downloads and executes a specified version of
This is different from earlier iterations of this tool that always rebuilt from source.
The current iteration requires a (possible snapshot deployment) first, that is then referenced in
Consequently, merging larger-scale changes to both the tool itself and the wrapper script need to be mindful of this dependency:
A new release (or at minimum a snapshot deployment) is needed, which is then referenced in
|As of May 2020, everyone can deploy snapshots to Artifactory, so permissions issues shouldn’t hinder development.|
Working with htaccess/mod_rewrite rules
The wrapper script
site/generate.sh calls the script
site/generate-htaccess.sh with chosen arguments.
The latter script will generate the
.htaccess file mostly containing mod_rewrite rules to redirect requests to appropriate tiered update sites.
To learn more about tiers, see LAYOUT.md.
To test changes to
site/generate-htaccess.sh and places it inside an Apache HTTPD Docker container and tests whether redirect rules are correctly applied.
Working with certificates
To sign JSON output files, create a development certificate:
openssl genrsa -out resources/certificates/demo.key 4096 openssl req -new -x509 -days 180 -key resources/certificates/demo.key -out resources/certificates/demo.crt -subj "/C=/ST=/L=/O=local-development/OU=local-development/CN=local-development/emailAddressemail@example.com"
Then add these arguments to your tool invocation (or arguments file):
--key resources/certificates/demo.key --certificate resources/certificates/demo.crt --root-certificate resources/certificates/demo.crt
To have your Jenkins instance accept update site JSON signed with this certificate, create a directory
update-center-rootCAs/ in the Jenkins home directory, and copy the
demo.crt file in there.
Once update site JSON files are generated, configure Jenkins to download them in Manage Jenkins » Manage Plugin » Advanced:
Either set up a local HTTP server so the URL would be something like
http://localhost:8000/update-center.json, or specify a
file:// URL like
For historical reason, the configured URL points to
Filtering Java versions
--java-version <version> CLI argument can be used to filter plugins based on their minimum Java version requirement.
By default such filtering happens based on the
Minimum-Java-Version manifest entry provided in Plugin HPIs starting from Maven HPI Plugin 3.0 and Plugin POM 3.29.
Plugin HPIs without
Minimum-Java-Version will be accepted by default.
If you want to create an update center for old Java, use the
--limit-plugin-core-dependency option to set the filter for core dependencies in plugins.