“ When” is the conditional derivate of the Jenkins declarative pipeline. Just like “IF” conditions, “when” will have the one or more condition statement. This can be either for from the user input or from the Built-in conditions. “When” condition can be placed before “Agent” in stage or before input directive.
What does the ‘when block’ do in Jenkins pipeline?
This piece of Pipeline code instructs Jenkins to check whether the branch this build runs on is the ‘master’ branch. Jenkins should also check this before a suitable agent is found, to avoid unnecessary usage of agents and slower builds. The documentation states the following about the when block:.
What is a node block in a Jenkins pipeline?
In Scripted Pipeline syntax, one or more node blocks do the core work throughout the entire Pipeline. Although this is not a mandatory requirement of Scripted Pipeline syntax, confining your Pipeline’s work inside of a node block does two things: Schedules the steps contained within the block to run by adding an item to the Jenkins queue.
How jenkins pipeline works?
Jenkins Pipeline is a combination of plugins that supports integration and implementation of continuous delivery pipelines. It has an extensible automation server to create simple and complex delivery pipelines as code via pipeline DSL. A Pipeline is a group of events interlinked with each other in a sequence.
Rationale: The idea of the declarative pipeline is to keep it simple without complex algorithms in it. When you are tempted to use if statements, loops, etc. in your Jenkinsfile, ask yourself if you are doing the right thing.
What are pipeline steps in Jenkins?
Basically, steps tell Jenkins what to do and serve as the basic building block for both Declarative and Scripted Pipeline syntax. For an overview of available steps, please refer to the Pipeline Steps reference which contains a comprehensive list of steps built into Pipeline as well as steps provided by plugins.
Jenkins Pipeline (or simply “Pipeline” with a capital “P”) is a suite of plugins which supports implementing and integrating continuous delivery pipelines into Jenkins.
Agent The agent section specifies where the entire Pipeline, or a specific stage, will execute in the Jenkins environment depending on where the agent section is placed. The section must be defined at the top-level inside the pipeline block, but stage-level usage is optional. Differences between top and stage level Agents.
In contrast to freestyle jobs, pipelines enable you to define the whole application lifecycle. Pipeline functionality helps Jenkins to support continuous delivery (CD). The Pipeline plugin was built with requirements for a flexible, extensible, and script-based CD workflow capability in mind. Accordingly, pipeline functionality is:.
What is a real time project in Jenkins?
But in real time projects, you will be responsible for creating and building complex pipelines in Jenkins. See below for a sample pipeline view. Any non-setup work in your pipeline should occur within a stage block. Any material work in a pipeline must be performed within a node block.