1. Overview
In this tutorial, we'll see how we can use comments in Jenkinsfile. We will cover different types of comments and their syntax.
2. Comments in a Jenkinsfile
The syntax of Jenkinsfile is based on Groovy, so it's possible to use Groovy syntax for comments. Let's take a simple example of Pipeline Linter and try to comment it out.
2.1. Single-Line Comments
Single-line comments in Jenkinsfile are the same as we see in popular languages like Java, C++, and C#.
They start with two forward slashes (//). Any text between // and the end of the line is commented and ignored in Jenkinsfile.
Let's use single-line comments to comment out a basic pipeline definition:
//pipeline {
// agent any
// stages {
// stage('Initialize') {
// steps {
// echo 'Hello World'
// }
// }
// }
//}2.2. Block Comments
Block comments in Jenkinsfile are used to comment out a block of code. Again, the pattern is similar to Java and C++.
A block comment starts with a forward-slash followed by an asterisk (/*) and ends with an asterisk followed by a forward-slash (*/). The beginning (/*) and ending (*/) characters will be added to the appropriate places to mark the selected block as a comment.
In this example, we'll use block comments to comment out the pipeline definition:
/*
pipeline {
agent any
stages {
stage('Initialize') {
steps {
echo 'Placeholder.'
}
}
}
}
*/
2.3. Comments in Shell Script
While inside of a shell (sh) section, we'll be using the shell comment character, hash (#), for commenting:
pipeline {
agent any
stages {
stage('Initialize') {
steps {
sh '''
cd myFolder
# This is a comment in sh & I am changing the directory to myFolder
'''
}
}
}
}3. Conclusion
In this short article, we covered different types of comments in a Jenkinsfile. First, we looked at single-line comments. Next, we saw how to use block comments. Finally, we showed how to add comments within a shell section of a Jenkinsfile.
The post Comments in a Jenkinsfile first appeared on Baeldung.
