feat(job_release): allow nested job folders

# Changelog

All notable changes to this job will be documented in this file.

## [1.0.0] - 2022-11-23

* Allow to fetch jobs from nested directories

* Use snippet maintained by R2Devops instead of external resource

## [0.1.0] - 2022-10-14

* Initial version

## Objective

Retrieve all versions of multiple jobs and create release for each entry inside their `CHANGELOG.md` files 

Retrieve all job templates from a repository and create GitLab release (and git tag) for each versions listed in `CHANGELOG.md`

## How to use it

   behavior, check the [variables section](#variables)

1. Well done, your job is ready to work and will be execute on your main branch ! 😀

## Behavior

By default, this job will be run on the `jobs` directory located at the root of your project and will create releases for each directory containing jobs files.

## Jobs files

Here's the structure of a job files :

**Here's the example structure of a job template folder:**

```

jobs 

   |

   job_name 

          |

          CHANGELOG.md

          job_name.yml

          README.md

   |

   job_name 

          |

          CHANGELOG.md

          job_name.yml

          README.md

docker_build/

  ├── README.md

  ├── CHANGELOG.md

  └── docker_build.yaml (containing a job named docker_build )

```

A `CHANGELOG.md` is required to create the releases

- The structure of the `CHANGELOG.md` is based on [keepachangelog](https://keepachangelog.com/en/1.0.0/) structure.

- You could also checkout the [R2Devops documentation](https://docs.r2devops.io/job-structure/#job-changelogs) about it

A `CHANGELOG.md` is require for creating git tags release.

The structure of the `CHANGELOG.md` is based on [keepachangelog](https://keepachangelog.com/en/1.0.0/) structure.

You could also checkout the [R2Devops documentation](https://docs.r2devops.io/job-structure/#job-changelogs) about it

Here's an example of a `CHANGELOG.md` :

**Here's an example of a `CHANGELOG.md`:**

```

# Changelog

All notable changes to this job will be documented in this file.

## [0.1.0] - 2022-10-14

## [1.1.0] - 2021-06-21

* Allows context different from root with new variable `DOCKER_CONTEXT_PATH`

## [1.0.0] - 2021-05-07

* Breaking change in the configuration of custom registry, see documentation

* Add support to push in multiple registries

* Add support to authentication in multiple registries

## [0.3.0] - 2020-11-25

* New variable `DOCKER_USE_CACHE` to be able to cache layers of build

* New variable `DOCKER_OPTIONS` to be able to add additional options

## [0.1.0] - 2020-10-21

* Initial version

```

| Name | Description | Default |

| ---- | ----------- | ------- |

| `JOBS_DIRECTORY` <img width=100/> | The directory containing the jobs folders | `jobs` <img width=100/>|

| `JOBS_DIRECTORY` | The root directory containing the job folders | `.` |

| `IMAGE_TAG` | The default tag for the docker image [alpine/httpie](https://hub.docker.com/r/alpine/httpie) | `3.2.1` |

| `GITLAB_API_URL` | The url used to call the GitLab API. ⚠️ It should be changed if you using a self-hosted version | `gitlab.com` |

| `GITLAB_API_URL` | The domain of GitLab instance. ⚠️ It should be changed if you using a self-hosted version | `gitlab.com` |

| `CHANGELOG_FILE` | The name of changelog files (case insensitive) | `CHANGELOG.md` |

## Author

This resource is an **[official job](https://docs.r2devops.io/faq-labels/)** added in [**R2Devops repository**](https://gitlab.com/r2devops/hub) by [@Totara-thib](https://gitlab.com/Totara-thib)

    name: alpine/httpie:${IMAGE_TAG}

    entrypoint: [""]

  variables:

    JOBS_DIRECTORY: "jobs"

    JOBS_DIRECTORY: "."

    IMAGE_TAG: "3.2.1"

    GITLAB_API_URL: "gitlab.com"

    CHANGELOG_FILE: "CHANGELOG.md"

  before_script:

    - apk update && apk add --no-cache bash

    - pip install --ignore-installed distlib pipenv

    - pipenv install

  script: >

    PROJECT_ENCODED=$(/bin/bash -c "$(http --ignore-stdin --body https://gist.githubusercontent.com/cdown/1163649/raw/8a35c36fdd24b373788a7057ed483a5bcd8cd43e/gistfile1.sh) && _encode '$CI_PROJECT_PATH'");

    for JOB in ${JOBS_DIRECTORY}/*; do

      JOB=$(basename ${JOB})

  script:

    # Url encode the project name

    - PROJECT_ENCODED=$(/bin/bash -c "$(http --ignore-stdin --body https://gitlab.com/r2devops/hub/-/snippets/2462394/raw/92c7e820e5b7ce468d8031748e1a57c24c67f6a4/_encode.sh) && _encode '$CI_PROJECT_PATH'")

    # Search for all changelog files

    - JOBS="$(find $JOBS_DIRECTORY -iname $CHANGELOG_FILE)"

    - for JOB in $JOBS; do

        # Extract the job name (this is the folder name)

    -   JOB_NAME=$(basename $(dirname $JOB))

        # Retrieve all versions of the job inside the CHANGELOG file, ## [(0.2.0)] - 2021-04-20 => get only this part ()

      VERSIONS=$(sed -rn 's/^##\s*\[\s*([^\ ]*)\s*\]\s*-\s*[0-9]{4}-[0-9]{2}-[0-9]{2}\s*/\1/p' ${JOBS_DIRECTORY}/${JOB}/CHANGELOG.md)

      for VERSION in ${VERSIONS}; do

    -   VERSIONS=$(sed -rn 's/^##\s*\[\s*([^\ ]*)\s*\]\s*-\s*[0-9]{4}-[0-9]{2}-[0-9]{2}\s*/\1/p' ${JOB})

    -   for VERSION in ${VERSIONS}; do

          #Retrieve the changes between two versions

        CHANGELOG=$(sed -n "/^##\s*\[\s*${VERSION}\s*\]/,/^##/p" ${JOBS_DIRECTORY}/${JOB}/CHANGELOG.md | sed -e '/^$/d' | head -n -1 | tail -n +2)

    -     CHANGELOG=$(sed -n "/^##\s*\[\s*${VERSION}\s*\]/,/^##/p" $JOB | sed -e '/^$/d' | head -n -1 | tail -n +2)

          #For initial version, we don't have a previous version, so set to default message

        [ -z "${CHANGELOG}" ] && CHANGELOG=$(sed -n "/^##\s*\[\s*$VERSION\s*\]/,/^[^##]/p" ${JOBS_DIRECTORY}/${JOB}/CHANGELOG.md | sed -e '/^$/d' | tail -n +2)

    - |

          [ -z "${CHANGELOG}" ] && CHANGELOG=$(sed -n "/^##\s*\[\s*$VERSION\s*\]/,/^[^##]/p" $JOB | sed -e '/^$/d' | tail -n +2)

          result=$(http --ignore-stdin POST https://${GITLAB_API_URL}/api/v4/projects/$PROJECT_ENCODED/releases \

            "JOB-TOKEN: ${CI_JOB_TOKEN}" \

          tag_name=${JOB}-${VERSION} \

            tag_name=${JOB_NAME}-${VERSION} \

            ref=${CI_COMMIT_SHA} \

            "description=${CHANGELOG}")

          if [ $(echo $result | grep "Release already exists\|${JOB}-${VERSION}" | wc -l) -eq 0 ]; then

            echo "[ERROR] Problem when attempting to create release ${JOB}-${VERSION}"

            echo "[ERROR] ${result}"

            exit 1;

          else

            if [ $(echo ${result} | grep "Release already exists" | wc -l) -eq 0 ]; then

              echo "New version detected for $JOB-$VERSION"

            fi

            echo "Processed ${JOB}-${VERSION} : ${result}";

          fi

      done

    done

    -       if [ $(echo $result | grep "Release already exists\|${JOB_NAME}-${VERSION}" | wc -l) -eq 0 ]; then

    -         echo "[ERROR] Problem when attempting to create release ${JOB_NAME}-${VERSION}"

    -         echo "[ERROR] ${result}"

    -         exit 1;

    -       else

    -         if [ $(echo ${result} | grep "Release already exists" | wc -l) -eq 0 ]; then

    -           echo "New version detected for $JOB_NAME-$VERSION"

    -         fi

    - |

            echo "Processed ${JOB_NAME}-${VERSION} : ${result}"

    -       fi

    -   done

    - done

  rules:

    - if: '$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH'