Jenkins Concepts: Difference between revisions

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=Node=
=Node=


A machine which is part of the Jenkins environment and capable of executing Pipelines or Projects. Both the [[#Master|masters]] and [[#Agent|agents]] are considered to be nodes.
A machine which is part of the Jenkins environment and capable of executing [[#Pipeline|pipelines]] or [[#Project|projects]]. Both the [[#Master|masters]] and [[#Agent|agents]] are considered to be nodes.


==Master==
==Master==

Revision as of 16:14, 11 September 2019

External

Internal

Node

A machine which is part of the Jenkins environment and capable of executing pipelines or projects. Both the masters and agents are considered to be nodes.

Master

Agent

An agent, also known as a "build agent", is the runtime that executes the build. Agents to execute a build may be selected with a Label Expression, specified in the job configuration.

Docker Plugin Agent

Docker Plugin Agent

Label

Label Expressions

Slave

Job

Equivalent with Project.

Jobs can be created from the UI and they show up on the dashboard, in the main table. A job state is maintained in $JENKINS_HOME/jobs/<job-name>. The job directory contains a config.xml and a "builds" subdirectory, which contains build state. The state include links to "lastFailedBuild", "lastStableBuild", "lastSuccessfulBuild", "lastUnstableBuild" and "lastUnsuccessfulBuild".

A job can be configured with Jenkins -> job -> Configure.

A job's configuration contains the following:

  • General Configuration
  • Source Code Management configuration
  • Build Triggers
  • Build Environment
  • Build definition - usually a shell command.
  • Post-build actions.

Each job has its own security context.

Build

A build belongs to a job.

Project

Equivalent with Job.

Items

Freestyle Project

Pipeline

https://jenkins.io/doc/book/pipeline/overview/

A Jenkins Pipeline is a suite of plugins that implement a continuous delivery pipeline. When integrated with OpenShift, the Jenkins Pipeline functionality provides the engine for OpenShift Pipeline builds. More details about OpenShift Jenkins pipeline are available here:

OpenShift Jenkins Pipelines

More details about the pipeline syntax are available here:

Jenkins Pipeline Syntax

View

Build Environment

OpenShift Jenkins Build Environment

Distributed Build

https://wiki.jenkins.io/display/JENKINS/Distributed+builds

Plugin

https://wiki.jenkins.io/display/JENKINS/Plugin+tutorial

The list of installed plugins can be obtained on the console Jenkins -> Manage Jenkins -> Manage Plugins -> Installed.

Interesting Jenkins Plugins

Server Administration Concepts

Instance State

A Jenkins instance state consists of the following:

  • The WAR file
  • Plugins.
  • Settings
  • Build logs
  • Artifacts archives
  • Jobs
  • Various temporary files associated with running the jobs, including repository clones: "jenkins_home/workspace/test-build/.git/..."

Everything mentioned above is stored under $JENKINS_HOME. It is sufficient to archive this directory to make a back up of the instance. Similarly, restoring the data is just replacing the contents of the JENKINS_HOME directory from a back up.

The WAR file is stored under ${JENKINS_HOME}/war. The location can be overridden with --webroot=<new-location>. The WAR is expanded during the startup sequence.

The plugins are stored under ${JENKINS_HOME}/plugins. The location can be overridden with --pluginroot =<new-location>.

Jenkins on Docker

Running Jenkins as a Docker Container

Running Jenkins as a Docker Container

Running Build Agents as Docker Containers

Jenkins Docker Plugin

CLI

Jenkins CLI

Security

Security Concepts