Objectives 🚀

• Common style guide across multiple projects;
• Improving code quality and reducing the bug occurrence probability;
• Eliminating the need for humans to check for code formatting and basic bad practices;
• Covering multiple languages (Groovy, Python, Terraform, YAML, etc.);
• Cross-platform setup, working the same way in CI and locally;
• Happier engineers 🥳

Tools 🛠

Language	Linter	Formatter
Groovy	CodeNarc	IntelliJ
Python	pylint *	PyCharm *
Shell	Shellcheck *	shfmt / IntelliJ? *
Terraform	😞	terraform fmt
YAML	yamllint	😞
YAML (k8s)	kubeval *	😞

Running Locally 👨‍💻

Example: jenkins-job-dsl-seed-jobs

Makefile Example

        
CODENARC='docker.io/abletonag/groovylint:0.7.1'

.PHONY: lint
lint:
    @docker run --rm -v `pwd`:/ws -u `id -u`:`id -g` \
        $(CODENARC) python3 /opt/run_codenarc.py -- \
            -includes='**/Jenkinsfile,**/*.groovy,**/*.dsl' \
            -rulesetfiles=file\:ruleset.groovy
        
        

Running in CI 🤖

Running in CI 🤖

            
stage('Lint') {
  steps {
    container('docker') { runCodeChecks() }
  }
  post {
    always { postCodeChecks() }
    failure { archiveArtifacts '*.log' }
  }
}
            
        

Example

CodeNarc 👮‍‍

CodeNarc analyzes Groovy code for defects, bad practices, inconsistencies, style issues and more. A flexible framework for rules, rulesets and custom rules means it's easy to configure CodeNarc to fit into your project.

• 380 rules 🙀
• 20+ rule categories: design, convention, formatting, naming, security etc.
• Congifured via ruleset.groovy in the root of a repo

CodeNarc 👮‍‍

            make lint
        

            ...
INFO Scanned 613 files
ERROR src/main/groovy/util/Versions.groovy:33:
    SpaceAfterOpeningBrace: [empty message]
ERROR src/main/groovy/util/Versions.groovy:33:
    SpaceBeforeClosingBrace: [empty message]
ERROR Found 2 violation(s)
make: *** [lint] Error 1
        

Future Ruleset Improvements

• Enable EmptyCatchBlock

def myMethod() {
    try {
        doSomething()
    } catch(MyException e) { ❌
    }
}

Future Ruleset Improvements

• Enable InvertedIfElse

if (!x) { ❌
    return false
} else {
    return true
}

• Reduce limit for LineLength (currently 210)
• ⚠️ Reduce limit for CyclomaticComplexity (currently 20)

Future Ruleset Improvements

• Enable ClosureAsLastMethodParameter

  [1, 2, 3].each({ println it }) ❌
  [1, 2, 3].each { println it } ✅
  

• Enable UnnecessaryGString

  def a = "key1" ❌
  def b = 'key1' ✅
  def c = "key${keyNum}" ✅
  

Next Steps 📈

• Add the rest of the linters/formatters to the most used projects:
  • gcloud-infrastructure
  • jenkins-global-shared-library
  • cawemo/jenkins-shared-libs
  • cawemo/infrastructure
• Pre-commit hooks?