chore(unit-tests) generate test fixtures from Puppetfile

[dduportal]

This PR is a big cleanup on the Puppet unit test to ensure that we can keep it working and upgrade dependencies in the future. Had to untangle quite some elements but it's hard to split into small PRs, so here we go.

EDIT: please only take teh "ci.jenkins.io" check, not the infra.ci.jenkins.io one.

It introduces the following changes:

• Remove the file .fixtures.yml from the repository:

  • This file duplicates the content of Puppetfile and required manual copy and paste, leading to unit test running with different puppet modules than production
  • Added to gitignore and generated through the generate-puppetfile new ruby gem which reads Puppetfile and generates

• Fix the Puppet code to support both Puppet v4 (version used for unit tests) and v6 (production server), using Puppet formatter for most of them:

  • include directive does not need the:: prefix anymore when loading a top-level module
  • ensure says file instead of present for resources of type file
  • ensure is deprecated for concat::fragment resource

• Fix Unit Tests Harness with the errors raised by the having an up-to-date .fixtures.yml file:

  • Correctly manage facter's mock facts to support both Puppet v4 and v6 in spec/spec_helper.rb
  • Stop testing for default values of the apache::mod::status module as it's not available in this mocked context with recent versions (should be an acceptance test)
  • Fix census tests that were checking a deprecated attrbitue for the resource concat::fragment

• Update the Pipeline (Jenkinsfile):

  • Update + cleanupo the shell scripts and Rakefile to make sure that both pipeline and local development can behave the same
  • Only spawn 1 agent for the whole build and run steps in parallels. Consumes less executors, and the dependencies are solved once per build. it's not faster, but ensure our builds are not stuck when there is a hugh activity on ci.jenkins.io
  • No need for junit test results (at least with our outdated dependencies for ruby specs gems)
  • Archive the .fixtures.yml file generated during the build for auditing purpose

• Documentation: README updated (was long due)

Please note that with this PR, we can start thinking about:

• Bumping dependencies on Gemfile to recent (and decent) versions including Puppet v4 to v6
• Bump Ruby dependency to 3.x (or at least 2.7) #2247
• Bring back automated acceptance testing for roles #2248
• Bring back the Acceptance Test Harness #2249
• Acceptance Tests: allow "Per VM" tests #2250
• Bumping dependences on Puppetfile

[lemeurherve]

Great job! 🎉

[smerle33]

sounds great
🚀