Jenkins: Scripted vs Declarative Pipelines



Scripted is a general purpose DSL and executed from the top of a `Jenkinsfile` downwards like most traditional scripts in Groovy.

E.g. of if/else and try/catch/throw



  • Declarative pipelines have a `pipeline` block. e.g.
pipeline {
    /*... code here ...*/
  • executing a scripted pipeline in a Declarative Pipeline

a script step takes a block of Scripted Pipeline and executes that in the Declarative Pipeline

Jenkins: node, stage, step


node allocates an executor on a Jenkins node (aka a slave) and runs code in the context of the workspace on that node.

Another wrinkle on node‘s. There is also the concept of flyweight and heavyweight executors. A flyweight executor is just a thread and runs inside the Java master’s JVM. A heavyweight executor is a process (e.g. `sh` ) and will halt the flow on the master so should be allocated to a node. From the docs:

It is recommended to allocate executors to agent machines, rather than on the Jenkins master – to avoid potential security vulnerabilities, Out-Of-Memory and other performance issues. To do this, configure the “# of executors” to ‘0’ on the “master” node (by default this setting is ‘2’).

See also


`stage` creates a labelled block and show up as columns in the Pipeline Stage view.

See also Jenkins: milestone plugin and this post on Stage vs Lock vs Milestone.


A step is a single action. When a step succeeds it moves onto the next step. When a step fails to execute correctly the Pipeline will fail.

See also


Note also the keyword steps


Jenkins CLI

Jenkins has a built-in command line interface that allows you to access Jenkins from a script or from your shell. This is convenient for automation of routine tasks, bulk updates, trouble diagnosis, and so on.

This interface is accessed via the Jenkins CLI client, which is a Java JAR file distributed with Jenkins.

You can download the JAR file for the client from the URL “/jnlpJars/jenkins-cli.jar” on your Jenkins server, e.g.

E.g. for `help`, use:

java -jar /var/lib/jenkins/cli/jenkins-cli.jar -auth <jenkins username>:<jenkins password> -s http://localhost:8080 help

Other options (instead of help):

  • safe_restart
  • version