Multi-Method Steps

While learning about Pipeline Lifecycle Hooks, we created a step that:

implemented multiple methods
did not implement a call method

In this section, we’re going to dive into multi-method steps in a little more detail.

Have you ever wondered why library steps create a method named call? This is because, in groovy, something() gets translated to something.call().

If we understand this concept, then it would make sense that we could define other methods within our steps and invoke them by their full name.

When to use Multi-Method Steps

The most common use case for defining multiple methods inside one step file is when you’re creating some utility functionality.

To demonstrate this, let’s create a mock git utility that can add, commit, and push.

Create the Git Library

In the same Pipeline Configuration Repository we used for JTE: The Basics, create a git library.

Because we’re creating a git utility, add a file called git.groovy with the contents:

/*
    takes an arraylist of files to pass to git add
*/
void add(ArrayList files){
    println "git add ${files.join(" ")}"
}

/*
    takes a string commit message to pass to git commit
*/
void commit(String message){
    println "git commit -m ${message}"
}

/*
    performs the git push
*/
void push(){
    println "git push"
}

In this example, we’re creating a step that serves as a utility wrapper. These are typically not invoked directly by Pipeline Templates but rather consumed by other steps. That is why it is okay, in this case, to accept input parameters for these methods.

We will be invoking this functionality directly from the Pipeline Template to demonstrate its functionality.

The filestructure for your Pipeline Configuration libraries directory should now be:

.
├── libraries
    ├── ansible
    │   └── steps
    │       └── deploy_to.groovy
    ├── git
    │   └── steps
    │       └── git.groovy
    ├── gradle
    │   └── steps
    │       └── build.groovy
    ├── maven
    │   └── steps
    │       └── build.groovy
    ├── sonarqube
    │   └── steps
    │       └── static_code_analysis.groovy
    └── splunk
        └── steps
            ├── splunk_pipeline_end.groovy
            ├── splunk_pipeline_start.groovy
            └── splunk_step_watcher.groovy

Update the Pipeline Configuration

Update the Pipeline Configuration to load the git library.

The libraries portion of the Pipeline Configuration should now be:

libraries{
    maven
    sonarqube
    ansible
    splunk{
        afterSteps = [ "static_code_analysis", "unit_test" ]
    }
    git
}

Use the new Git Utility

Prepend to the existing Pipeline Template:

git.add(["a", "b", "c"])
git.commit "my commit message"
git.push()

Important

When invoking a non-call method defined within a step, you do so by <step_name>.<method_name>(<arguments>).

Run the Pipeline

Run the pipeline again and you will see logs similar to:

Started by user admin
Running in Durability level: MAX_SURVIVABILITY
[Pipeline] Start of Pipeline
[JTE] Pipeline Configuration Modifications (show)
[JTE] Loading Library maven (show)
[JTE] Library maven does not have a configuration file.
[JTE] Loading Library sonarqube (show)
[JTE] Library sonarqube does not have a configuration file.
[JTE] Loading Library ansible (show)
[JTE] Library ansible does not have a configuration file.
[JTE] Loading Library splunk (show)
[JTE] Library splunk does not have a configuration file.
[JTE] Loading Library git (show)
[JTE] Library git does not have a configuration file.
[JTE] Creating step unit_test from the default step implementation.
[JTE] Obtained Pipeline Template from job configuration
[Pipeline] node
Running on Jenkins in /var/jenkins_home/workspace/single-job
[Pipeline] {
[Pipeline] writeFile
[Pipeline] archiveArtifacts
Archiving artifacts
[Pipeline] }
[Pipeline] // node
[JTE] [@Init - splunk/splunk_pipeline_start.call]
[Pipeline] echo
Sending Splunk event for beginning of the pipeline!
[JTE] [@BeforeStep - splunk/splunk_step_watcher.before]
[Pipeline] echo
Splunk: running before the git library's git step
[JTE] [Step - git/git.add(ArrayList)]
[Pipeline] echo
git add a b c
[JTE] [@BeforeStep - splunk/splunk_step_watcher.before]
[Pipeline] echo
Splunk: running before the git library's git step
[JTE] [Step - git/git.commit(String)]
[Pipeline] echo
git commit -m my commit message
[JTE] [@BeforeStep - splunk/splunk_step_watcher.before]
[Pipeline] echo
Splunk: running before the git library's git step
[JTE] [Step - git/git.push()]
[Pipeline] echo
git push
[JTE] [Stage - continuous_integration]
[JTE] [@BeforeStep - splunk/splunk_step_watcher.before]
[Pipeline] echo
Splunk: running before the Default Step Implementation library's unit_test step
[JTE] [Step - Default Step Implementation/unit_test.call()]
[Pipeline] stage
[Pipeline] { (Unit Test)
[Pipeline] node
Running on Jenkins in /var/jenkins_home/workspace/single-job
[Pipeline] {
[Pipeline] isUnix
[Pipeline] sh
+ docker inspect -f . maven
.
[Pipeline] withDockerContainer
Jenkins seems to be running inside container cc7140d4fb91bef940e2fabe7225dcbcc9b44a3a5e17ee703b8fcbe42e53a17c
$ docker run -t -d -u 0:0 -w /var/jenkins_home/workspace/single-job --volumes-from cc7140d4fb91bef940e2fabe7225dcbcc9b44a3a5e17ee703b8fcbe42e53a17c -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** maven cat
$ docker top 4bedf0c251a44759408b76ac7dc6db2bebef8438f95018911a0424dfeb68f18d -eo pid,comm
[Pipeline] {
[Pipeline] unstash
[Pipeline] sh
+ mvn -v
Apache Maven 3.6.2 (40f52333136460af0dc0d7232c0dc0bcf0d9e117; 2019-08-27T15:06:16Z)
Maven home: /usr/share/maven
Java version: 11.0.5, vendor: Oracle Corporation, runtime: /usr/local/openjdk-11
Default locale: en, platform encoding: UTF-8
OS name: "linux", version: "4.9.125-linuxkit", arch: "amd64", family: "unix"
[Pipeline] }
$ docker stop --time=1 4bedf0c251a44759408b76ac7dc6db2bebef8438f95018911a0424dfeb68f18d
$ docker rm -f 4bedf0c251a44759408b76ac7dc6db2bebef8438f95018911a0424dfeb68f18d
[Pipeline] // withDockerContainer
[Pipeline] }
[Pipeline] // node
[Pipeline] }
[Pipeline] // stage
[JTE] [@AfterStep - splunk/splunk_step_watcher.after]
[Pipeline] echo
Splunk: running after the Default Step Implementation library's unit_test step
[JTE] [@BeforeStep - splunk/splunk_step_watcher.before]
[Pipeline] echo
Splunk: running before the maven library's build step
[JTE] [Step - maven/build.call()]
[Pipeline] stage
[Pipeline] { (Maven: Build)
[Pipeline] echo
build from the maven library
[Pipeline] }
[Pipeline] // stage
[JTE] [@AfterStep - splunk/splunk_step_watcher.after]
[Pipeline] echo
Splunk: running after the maven library's build step
[JTE] [@BeforeStep - splunk/splunk_step_watcher.before]
[Pipeline] echo
Splunk: running before the sonarqube library's static_code_analysis step
[JTE] [Step - sonarqube/static_code_analysis.call()]
[Pipeline] stage
[Pipeline] { (SonarQube: Static Code Analysis)
[Pipeline] echo
static code analysis from the sonarqube library
[Pipeline] }
[Pipeline] // stage
[JTE] [@BeforeStep - splunk/splunk_step_watcher.before]
[Pipeline] echo
Splunk: running before the ansible library's deploy_to step
[JTE] [Step - ansible/deploy_to.call(ApplicationEnvironment)]
[Pipeline] stage
[Pipeline] { (Deploy To: dev)
[Pipeline] echo
performing a deployment through ansible..
[Pipeline] echo
deploying to 0.0.0.1
[Pipeline] echo
deploying to 0.0.0.2
[Pipeline] }
[Pipeline] // stage
[Pipeline] timeout
Timeout set to expire in 5 min 0 sec
[Pipeline] {
[Pipeline] input
Approve the deployment?
Proceed or Abort
Approved by admin
[Pipeline] }
[Pipeline] // timeout
[JTE] [@BeforeStep - splunk/splunk_step_watcher.before]
[Pipeline] echo
Splunk: running before the ansible library's deploy_to step
[JTE] [Step - ansible/deploy_to.call(ApplicationEnvironment)]
[Pipeline] stage
[Pipeline] { (Deploy To: Production)
[Pipeline] echo
performing a deployment through ansible..
[Pipeline] echo
deploying to 0.0.1.1
[Pipeline] echo
deploying to 0.0.1.2
[Pipeline] echo
deploying to 0.0.1.3
[Pipeline] echo
deploying to 0.0.1.4
[Pipeline] }
[Pipeline] // stage
[JTE] [@CleanUp - splunk/splunk_pipeline_end.call]
[Pipeline] echo
Splunk: end of the pipeline!
[Pipeline] End of Pipeline
Finished: SUCCESS

Pipeline Lifecycle Hooks

Summary