This a Jenkins library built to make it easier for us at Wolox to configure pipelines without necessarily knowing about Jenkinsfile syntax. All our projects are built using a Dockerfile

When using this library, your Jenkinsfile should look something like this:

@Library('jenkins-yaml') _

node {

  checkout scm

  jenkinsYAML('docker/config.yml');
}

It basically loads the library, clones the target repository and calls jenkinsYAML to make its magic. As an argument, jenkinsYAML receives the path to a configuration yaml file. This file looks something like this:

config:
  dockerImage: library/redis
  project_name: some-rails-project

services:
  - mssql

steps:
  analysis:
    - bundle exec rubocop -R app spec --format simple
    - bundle exec rubycritic --path ./analysis --minimum-score 80 --no-browser
  setup_db:
    - bundle exec rails db:create
    - bundle exec rails db:schema:load
  test:
    - bundle exec rspec
  security:
    - bundle exec brakeman --exit-on-error
  audit:
    - bundle audit check --update


environment:
  RAILS_ENV: test
  GIT_COMMITTER_NAME: a
  GIT_COMMITTER_EMAIL: b
  LANG: C.UTF-8

This file has different sections:

The section under the config label defines some basic configuration for this project:

1. The dockerfile that contains the image for the project to run.
2. The project name.

This section lists the project's dependencies. Each section will define and expose some environment variables that might be needed by the application:

When listing mssql as a service, this will build a docker image from microsoft/mssql-server-linux exposing the following environment variables:

1. DB_USERNAME
2. DB_PASSWORD
3. DB_HOST
4. DB_PORT

When listing postgres as a service, this will build a docker image from postgres exposing the following environment variables:

1. DB_USERNAME
2. DB_PASSWORD
3. DB_HOST
4. DB_PORT

When listing redis as a service, this will build a docker image from redis exposing the following environment variables:

1. REDIS_URL: the redis url that looks like this redis://redis

This section lets you define the steps you need to build your project. Each level inside the steps section is a stage in the Jenkins pipeline and each item in the stage is a command to run. In the case above, there are 5 stages named:

1. analysis
2. setup_db
3. test
4. security
5. audit

The analysis stage, for example, runs the following commands:

1. bundle exec rubocop -R app spec --format simple
2. bundle exec rubycritic --path ./analysis --minimum-score 80 --no-browser

This section lets you set up custom environment variables. Each item inside this section defines a variable with its value.