[Backport release/3.2.x] chore(changelog): new way to maintain the changelog

.github/PULL_REQUEST_TEMPLATE.md

@@ -11,7 +11,7 @@ https://github.com/Kong/kong/blob/master/CONTRIBUTING.md#contributing
 ### Checklist
 
 - [ ] The Pull Request has tests
-- [ ] There's an entry in the CHANGELOG
+- [ ] A changelog file has been added to `CHANGELOG/unreleased/kong` or adding `skip-changelog` label on PR if unnecessary. [README.md](https://github.com/Kong/kong/CHANGELOG/README.md) (Please ping @vm-001 if you need help)
 - [ ] There is a user-facing docs PR against https://github.com/Kong/docs.konghq.com - PUT DOCS PR HERE
 
 ### Full changelog

.github/workflows/build_and_test.yml

@@ -5,6 +5,7 @@ on:
     # ignore markdown files (CHANGELOG.md, README.md, etc.)
     - '**/*.md'
     - '.github/workflows/release.yml'
+    - 'CHANGELOG/**'
   push:
     paths-ignore:
     # ignore markdown files (CHANGELOG.md, README.md, etc.)

.github/workflows/changelog.yaml

@@ -0,0 +1,43 @@
+name: Changelog
+
+on:
+  pull_request:
+    types: [ "opened", "synchronize", "labeled", "unlabeled" ]
+
+jobs:
+  require-changelog:
+    name: Is changelog required?
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 2
+
+      - name: Retrives changed files in CHANGELOG/unreleased/**/*.yaml
+        id: changelog-check
+        uses: tj-actions/changed-files@5817a9efb0d7cc34b917d8146ea10b9f32044968 # v37
+        with:
+          files: 'CHANGELOG/unreleased/**/*.yaml'
+
+      - name: Requires a changelog file if 'skip-changelog' label is not added
+        if: ${{ !contains(github.event.*.labels.*.name, 'skip-changelog') }}
+        run: >
+          if [ "${{ steps.changelog-check.outputs.added_files_count }}" = "0" ]; then
+            echo "PR should contain a changelog file"
+            exit 1
+          fi
+
+  validate-changelog:
+    name: Validate changelog
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Validate changelogs
+        uses: thiagodnf/yaml-schema-checker@228a5be72029114e3cd6301e0aaeef6b557fa033 # v0.0.8
+        with:
+          jsonSchemaFile: CHANGELOG/schema.json
+          yamlFiles: |
+            CHANGELOG/unreleased/*/*.yaml

CHANGELOG/Makefile

@@ -0,0 +1,3 @@
+install_dependencies:
+	luarocks install penlight --local
+	luarocks install lyaml --local

CHANGELOG/README.md

@@ -0,0 +1,88 @@
+# CHANGELOG
+
+The CHANGELOG directory is used for individual changelog file practice.
+The `kong/CHANGELOG.md` now is deprecated.
+
+
+## How to add a changelog file for your PR?
+
+1/ Copy the `changelog-template.yaml` file and rename with your PR number or a short message as the filename. For example, `11279.yaml`, `introduce-a-new-changelog-system.yaml`. (Prefer using PR number as it's already unique and wouldn't introduce conflict)
+
+2/ Fill out the changelog template.
+
+
+The description of the changelog file field, please follow the `schema.json` for more details.
+
+- message: Message of the changelog
+- type: Changelog type. (`feature`, `bugfix`, `dependency`, `deprecation`, `breaking_change`)
+- scope: Changelog scope. (`Core`, `Plugin`, `PDK`, `Admin API`, `Performance`, `Configuration`, `Clustering`)
+- prs: List of associated GitHub PRs
+- issues: List of associated GitHub issues
+- jiras: List of associated Jira tickets for internal track
+
+Sample 1
+```yaml
+message: Introduce the request id as core feature.
+type: feat
+scope: Core
+prs:
+  - 11308
+```
+
+Sample 2
+```yaml
+message: Fix response body gets repeated when `kong.response.get_raw_body()` is called multiple times in a request lifecycle.
+type: bugfix
+scope: PDK
+prs:
+  - 11424
+jiras:
+  - "FTI-5296"
+```
+
+
+## changelog command
+
+The `changelog` command tool provides `preview`, and `release` commands.
+
+### Prerequisites
+
+You can skip this part if you're at Kong Bazel virtual env.
+
+Install luajit
+
+Install luarocks libraries
+
+```
+luarocks install penlight --local
+luarocks install lyaml --local
+```
+
+### Usage
+
+```shell
+$ ./changelog -h
+
+Usage: changelog <command> [options]
+
+Commands:
+  release <version>                  release a release note based on the files in the CHANGELOG/unreleased directory.
+  preview <version>                  preview a release note based on the files in the CHANGELOG/unreleased directory.
+
+Options:
+  -h, --help                         display help for command
+
+Examples:
+  changelog preview 1.0.0
+  changelog release 1.0.0
+```
+
+**Preview a release note**
+```shell
+./changelog preview 1.0.0
+```
+
+**Release a release note**
+```shell
+./changelog release 1.0.0
+```