Expanding Jenkins Pipeline Functionality Through Shared Libraries

Transcript

1. Expanding Jenkins Pipeline Functionality Through Shared Libraries Charlotte Mays Red Hat Gr8Conf EU 2019
2. Welcome! • Who am I?
3. Welcome! • Who am I? • This talk
4. Welcome! • Who am I? • This talk • Resources
5. What is Jenkins? Jenkins is (text paraphrased from wikipedia): • an open source automation server • written in Java • to automate the non-human part of the software development process (continuous integration and continuous delivery)
6. Jenkins Pipelines - In Brief From Jenkins documentation (https://jenkins.io/doc/book/pipeline/): Jenkins Pipeline (or simply "Pipeline" with a capital "P") is a suite of plugins which supports implementing and integrating continuous delivery pipelines into Jenkins @charlottecodes
7. Why Jenkins Pipelines Code: • Checked into source control • Editable and iterable • Domain-Specific Language (DSL) ◦ Groovy-based @charlottecodes
8. Why Jenkins Pipelines Durable: • Survive restarts of the Jenkins master (planned or unexpected) @charlottecodes
9. Why Jenkins Pipelines Pausable: • Optional break points for human input or approval @charlottecodes
10. Why Jenkins Pipelines Versatile: • Support real-world continuous delivery requirements @charlottecodes
11. Why Jenkins Pipelines Extensible: • supports custom extensions to its DSL @charlottecodes
12. Uses For Shared Libraries • Reduce repetition @charlottecodes
13. Uses For Shared Libraries • Reduce repetition • Lower barrier to entry @charlottecodes
14. Uses For Shared Libraries • Reduce repetition • Lower barrier to entry • Increase compliance with best practices @charlottecodes
15. Uses For Shared Libraries • Reduce repetition • Lower barrier to entry • Increase compliance with best practices • Increase robustness of CI/CD @charlottecodes
16. Enough Why! Show Me The How @charlottecodes
17. Basic Pipeline Example stage("Build") { steps { sh "mvn clean install" } } stage("Report") { steps { report() } } @charlottecodes
18. Directory Structure • vars • src • resources @charlottecodes
19. Directory Structure vars • Script files exposed as 'variables' in Pipelines ◦ 'methods' might be more accurate • Help files also located here (with .txt extensions) @charlottecodes
20. Directory Structure src • Added to classpath ◦ Available to methods in vars and within Pipelines • Standard Java source directory structure @charlottecodes
21. Directory Structure resources • Allows libraryResource step to load non-Groovy files • Useful for templates, default config, etc • Standard Java source directory structure @charlottecodes
22. Basic Structure vars/report.groovy def call(ArrayList recipients) { // Send notification to recipients } @charlottecodes
23. Usage in Pipeline stage("Report") { steps { report([ "someEmail@company.com", "otherEmail@company.com" ]) } } @charlottecodes
24. Simplify Usage With Defaults def call(ArrayList recipients=["teamEmail@company.com"]) { // Send notification to recipients } @charlottecodes
25. Usage in Pipeline stage("Report") { steps { report() } } @charlottecodes
26. The Jenkins Environment def call(ArrayList recipients) { messageBody = """ Job Name: ${env.JOB_NAME} Job Build #: ${env.BUILD_NUMBER} Job URL: ${env.BUILD_URL} """ // send message with messageBody } @charlottecodes
27. What About Files? @charlottecodes Can we access files created inside the Jenkins environment?
28. What About Files? def call(ArrayList recipients) { // define messageBody // Append log to message messageBody += readFile( file: "${WORKSPACE}/log.txt" ) // send message with messageBody } @charlottecodes
29. Jenkins Steps Available Any step valid in Jenkins Pipeline DSL is valid in your library code Examples: • sh • git • Notification (slackSend, hipchatSend) • Lots of Jira hooks • And more….. @charlottecodes
30. Jenkins Steps Available def call() { git "my.repo.url@someBranch" sh "echo 'checked out someBranch' >> log.txt" }
31. Namespaced Calls def call(ArrayList recipients=[]) { // send message } def slack() { slackSend( message: "Info available at ${env.JOB_URL}" ) } @charlottecodes
32. Usage in Pipeline stage("Report") { steps { report() // Uses the `call` function report.slack() // Uses the `slack` function } } @charlottecodes
33. Closures withCredentials( [string(credentialsId: 'mytoken', variable: 'TOKEN')] ) { sh ''' set +x curl -H "Token: $TOKEN" https://some.api/ ''' } @charlottecodes
34. Closures def call(Map config=[:], Closure body){ // Any needed setup body() // Any needed teardown } @charlottecodes vars/withSomeAction.groovy
35. Error Handling • Option 1: allow error to propagate as normal • Option 2: catch error and process ◦ Pass to Jenkins using Jenkins error step ◦ Handle internally @charlottecodes
36. Error Handling def call(Map config=[:], Closure body){ // Any needed setup try { body() } catch(Exception e) { error e.toString() } // Any needed teardown } @charlottecodes
37. Testable • Pipeline as code means we can unit test! @charlottecodes
38. Testable • Pipeline as code means we can unit test! • But no Jenkins running during tests… ◦ Lots of mocking/stubbing! @charlottecodes
39. Testable • Pipeline as code means we can unit test! • But no Jenkins running during tests… ◦ Lots of mocking/stubbing! ◦ jenkins-spock by homeaway helps! @charlottecodes
40. Gr8! How Do People Use It? @charlottecodes
41. Using Your New Shared Library @charlottecodes
42. Using Your New Shared Library @charlottecodes
43. Using Your New Shared Library <scroll> @charlottecodes
44. Using Your New Shared Library
45. Adding Your Shared Library Name • Required • Arbitrary Default Version • Optional • Interpreted by SCM @charlottecodes
46. Adding Your Shared Library Load Implicitly • Makes shared library available without using @Library syntax inside the Pipeline Retrieval Method • Source code to be pulled in • Location, creds, etc @charlottecodes
47. Ready to Use! Jenkins jobs running on that master will now have access to shared library functions @charlottecodes
48. Reference @charlottecodes on Twitter Slides: - https://bit.ly/30rPplQ Example Repo: - https://github.com/openshift/contra-hdsl Jenkins Documentation: - https://jenkins.io/doc/book/pipeline/ - https://jenkins.io/doc/book/pipeline/shared-libraries/ Charlotte Mays Red Hat Gr8Conf EU 2019