Also this repository was used to present Shared libraries at work to my colegues
-
First ste was to show that before Jenkins 2 developers used to create Jenkins jobs manually via UI.
-
With release of Jenkins 2 developers provide ability to create different pipelines with the help of pipeline dsl.
-
Pipelines is really cool feature but in most cases we develop/support many small application and each applications need its own pipeline.
-
As a result Shared libraries appeared.
To create this repository I use official jenkins shared library documentation
As first example I created hello world application that just send print text that was inserted into helloWorld method:
// Jenkinsfile
node {
library (
identifier: 'first-lib@first-step', // unique name of your shared lib and branch/tag specifier
retriever:
modernSCM([
// ddownload shared library function
])
)
helloWorld "Test message"
}
// var/helloWorld.groovy
def call(String textMessage){
print textMessage
}
// Jenkinsfile
node{
def lib = library (
identifier: 'first-lib@first-step', // unique name of your shared lib and branch/tag specifier
retriever:
modernSCM([
// ddownload shared library function
])
)
helloWorld "Hello from library function"
library ("static-shared-lib@lib").by.bulgak.jenkins.lib.HelloWorld.new(this).say("Hello frm class")
helloWorld "Hello from library function"
lib.by.bulgak.jenkins.lib.HelloWorld.new(this).mvn("Hello frm class")
lib.by.bulgak.jenkins.lib.HelloWorldStatic.new().mvn("Hello frm class")
}
// MavenHelperStatic.groovy
import static Constants.MAVEN;
def mvn(String action, String mavenVersion = MAVEN) {
def mavenPath = tool "${mavenVersion}";
sh "${mavenPath}/bin/mvn ${action}"
}
// MavenHelper.groovy
import static Constants.MAVEN;
class MavenHelper implements Serializable {
def steps
MavenHelper(steps) {this.steps = steps}
def mvn(String action, String mavenVersion = MAVEN) {
try{
def mavenPath = steps.tool "${mavenVersion}";
return steps.sh("${mavenPath}/bin/mvn ${action}")
}catch(Exception ex){
print ex.getMessage();
}
}
So lets take a look at simple maven application that is build, tested and pushed into local maven repo with different approaches
- Simple jenkins pipeline
node {
stage("Checkout"){
checkout([
$class: 'GitSCM',
branches: [[name: 'refs/tags/general']],
doGenerateSubmoduleConfigurations: false,
userRemoteConfigs: [[
credentialsId: 'CREDENTIALS',
url: 'repo with source code'
]]
])
}
stage("Compile"){
sh("${tool 'Apache Maven 3.3.9'}/bin/mvn compile")
}
stage("Test"){
sh("${tool 'Apache Maven 3.3.9'}/bin/mvn test")
}
stage("Install"){
sh("${tool 'Apache Maven 3.3.9'}/bin/mvn install")
}
}
Here we just download repository with source code and move code through three stages: compie, test, install. This is common example and of couse we do not need any libraries for this case. But for case of study this example can be rewriten via MavenHelperStatic or MavenHelper
- Simple pipeline with some helper classes
/**
* To use code from shared library we need to initalize it
* in this example we use dynamic funtion to download shared library
* also you can use @Library static function
*/
def lib = library (
identifier: 'simple-lib@lib',
retriever:
modernSCM([
$class: 'GitSCMSource',
credentialsId: '92bb99b8-238f-4f06-8386-b45861c9dd76',
id: '42de5809-9017-4717-90f7-1e55cd53e5f7',
remote: 'git@github.com:aleksei-bulgak/jenkins-shared-library-example.git',
traits: [[$class: 'jenkins.plugins.git.traits.BranchDiscoveryTrait']]
])
)
/**
* we do not want to use complex checkout that is provided via pipeline
* sintax so we created simle Checkout class that accept two arguments
* firt - repository where source code is stored
* second - optional parameter if you want to specify non master branch
*/
lib.by.bulgak.jenkins.lib.Checkout.new().checkout(
"repo with source code",
"branch/tag" //master will be used by default
);
/**
* Here we initialize MavenHelperStatic funtion.
* of couse we could mode this code into `var/` folder and in this case
* initialization will be not needed
*/
def mvnStatic = lib.by.bulgak.jenkins.lib.MavenHelperStatic.new();
stage("Compile"){
//sh("${tool 'Apache Maven 3.3.9'}/bin/mvn compile")
mvnStatic.mvn("compile");
}
stage("Test"){
//sh("${tool 'Apache Maven 3.3.9'}/bin/mvn test")
lib.by.bulgak.jenkins.lib.MavenHelperStatic.new().mvn("test");
}
stage("Install"){
//sh("${tool 'Apache Maven 3.3.9'}/bin/mvn install")
def maven = lib.by.bulgak.jenkins.lib.MavenHelper.new(this);
maven.mvn("install");
}
- Same code with the help of var/mavenStep.groovy
node {
def lib = library (
identifier: 'first-lib@first-step', // unique name of your shared lib and branch/tag specifier
retriever:
modernSCM([
// ddownload shared library function
])
)
lib.by.bulgak.jenkins.lib.Checkout.new().checkout(
"repo with source code",
"branch/tag" //master will be used by default
);
mavenStep{
name = "Compile"
action = "compile"
}
mavenStep{
name = "Run Tests"
action = "test"
}
mavenStep{
name = "Build code and put into local repository"
action = "install"
}
}
- More complex code with builder classes
node {
def lib = library (
identifier: 'first-lib@first-step', // unique name of your shared lib and branch/tag specifier
retriever:
modernSCM([
// ddownload shared library function
])
)
stage("Checkout class"){
lib.by.bulgak.jenkins.lib.Checkout.new().checkout(
"repo with source code",
"branch/tag" //master will be used by default
);
}
stage("Maven builder"){
def mavenLib = lib.by.bulgak.jenkins.lib
def mvn = mavenLib.Maven.builder(this)
.action("clean install")
.argument(mavenLib.MavenArgument.create().withPrefix("-D").withKey("key").withName("value").build())
.argument(mavenLib.MavenArgument.create().withPrefix("-D").withKey("key2").withName("value2").build())
.silent(true)
.build();
def constants = mavenLib.Constants.new()
mvn.execute(constants.MAVEN);
}
}