Add go-changelog (#882)

* add changelog-build changelog-entry

* add github action for go-changelog

* tidy

* vendor

* small changelog details

.changelog/changelog.tmpl

@@ -0,0 +1,47 @@
+{{- if index .NotesByType "breaking-change" -}}
+BREAKING CHANGES:
+
+{{range index .NotesByType "breaking-change" -}}
+* {{ template "note" . }}
+{{ end -}}
+{{- end -}}
+
+{{- if .NotesByType.security }}
+SECURITY:
+
+{{range .NotesByType.security -}}
+* {{ template "note" . }}
+{{ end -}}
+{{- end -}}
+
+{{- if .NotesByType.feature }}
+FEATURES:
+
+{{range .NotesByType.feature -}}
+* {{ template "note" . }}
+{{ end -}}
+{{- end -}}
+
+{{- if .NotesByType.improvement }}
+IMPROVEMENTS:
+
+{{range .NotesByType.improvement -}}
+* {{ template "note" . }}
+{{ end -}}
+{{- end -}}
+
+{{- if .NotesByType.deprecation }}
+DEPRECATIONS:
+
+{{range .NotesByType.deprecation -}}
+* {{ template "note" . }}
+{{ end -}}
+{{- end -}}
+
+{{- if .NotesByType.bug }}
+BUG FIXES:
+
+{{range .NotesByType.bug -}}
+* {{ template "note" . }}
+{{ end -}}
+{{- end -}}

.changelog/note.tmpl

@@ -0,0 +1,3 @@
+{{- define "note" -}}
+{{.Body}}{{if not (stringHasPrefix .Issue "_")}} [[GH-{{- .Issue -}}](https://github.com/hashicorp/terraform-provider-helm/issues/{{- .Issue -}})]{{end}}
+{{- end -}}

.github/workflows/changelog-checker.yml

@@ -0,0 +1,36 @@
+# This workflow checks that there is either a 'pr/no-changelog' label applied to a PR
+# or there is a .changelog/<pr number>.txt file associated with a PR for a changelog entry
+name: Changelog Entry
+
+on:
+  pull_request:
+    types: [opened, synchronize, labeled]
+    # Runs on PRs to main and all release branches
+    branches:
+      - main
+
+jobs:
+  # checks that a .changelog entry is present for a PR
+  changelog-check:
+    # If there  a `pr/no-changelog` label we ignore this check
+    if: "!contains(github.event.pull_request.labels.*.name, 'pr/no-changelog')"
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+          fetch-depth: 0 # by default the checkout action doesn't checkout all branches
+      - name: Check for changelog entry in diff
+        run: |
+          # check if there is a diff in the .changelog directory
+          changelog_files=$(git --no-pager diff --name-only HEAD "$(git merge-base HEAD "origin/${{ github.event.pull_request.base.ref }}")" -- .changelog/${{ github.event.pull_request.number }}.txt)
+
+          # If we do not find a file in .changelog/, we fail the check
+          if [ -z "$changelog_files" ]; then
+            # Fail status check when no .changelog entry was found on the PR
+            echo "Did not find a .changelog entry and the 'pr/no-changelog' label was not applied. Reference - https://github.com/hashicorp/terraform-provider-helm/tree/main/.github/workflows/CHANGELOG_GUIDE.md"
+            exit 1
+          else
+            echo "Found .changelog entry in PR!"
+          fi

CHANGELOG_GUIDE.md

@@ -0,0 +1,111 @@
+# How To Use
+
+Helm Provider uses `go-changelog` to generate its changelog on release:
+
+* https://github.com/hashicorp/go-changelog
+
+To install, run the following commands:
+
+```
+go install github.com/hashicorp/go-changelog/cmd/changelog-build
+go install github.com/hashicorp/go-changelog/cmd/changelog-entry
+```
+
+Either command can be ran with the following make command:
+
+```
+make changelog
+make changelog-entry
+```
+
+## CHANGELOG entry examples
+
+CHANGELOG entries are expected to be txt files created inside this folder
+`.changelog`. The file name is expected to be the same pull request number that will
+be linked when the CHANGELOG is generated. So for example, if your pull request is
+\#1234, your file name would be `.changelog/1234.txt`.
+
+While for git commit messages, we expect the leading subject to be more specific
+as to the section it updates, for example a change with k8s might be:
+
+```
+builtin/k8s: Add support for feature Y
+
+This commit adds support for feature Y....
+```
+
+The changelog entry should be more user facing friendly, so it would instead read:
+
+~~~
+```release-note:improvement
+plugin/k8s: Add support for feature Y
+```
+~~~
+
+Below are some examples of how to generate a CHANGELOG entry with your pull
+request.
+
+### Improvement
+
+~~~
+```release-note:improvement
+server: Add new option for configs
+```
+~~~
+
+### Feature
+
+~~~
+```release-note:feature
+plugin/nomad: New feature integration
+```
+~~~
+
+### Bug
+
+~~~
+```release-note:bug
+plugin/docker: Fix broken code
+```
+~~~
+
+### Multiple Entries
+
+~~~
+```release-note:bug
+plugin/docker: Fix broken code
+```
+
+```release-note:bug
+plugin/nomad: Fix broken code
+```
+
+```release-note:bug
+plugin/k8s: Fix broken code
+```
+~~~
+
+### Long Description with Markdown
+
+~~~
+```release-note:feature
+cli: Lorem ipsum dolor `sit amet`, _consectetur_ adipiscing elit, **sed** do
+eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
+veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
+consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse
+cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non
+proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
+```
+~~~
+
+## How to generate CHANGELOG entries for release
+
+Below is an example for running `go-changelog` to generate a collection of
+entries. It will generate output that can be inserted into CHANGELOG.md.
+
+For more information as to what each flag does, make sure to run `changelog-build -help`.
+
+```
+changelog-build -last-release v0.5.0 -entries-dir .changelog/ -changelog-template changelog.tmpl -note-template note.tmpl -this-release 86b6b38faa7c69f26f1d4c71e271cd4285daadf9
+```
+

GNUmakefile

@@ -16,11 +16,30 @@ ifneq ($(origin TRAVIS_TAG), undefined)
 	VERSION := $(TRAVIS_TAG)
 endif
 
+# For changelog generation, default the last release to the last tag on
+# any branch, and this release to just be the current branch we're on.
+LAST_RELEASE?=$$(git describe --tags $$(git rev-list --tags --max-count=1))
+THIS_RELEASE?=$$(git rev-parse --abbrev-ref HEAD)
+
 default: build
 
 build: fmtcheck
 	go build -v .
 
+# expected to be invoked by make changelog LAST_RELEASE=gitref THIS_RELEASE=gitref
+changelog:
+	@echo "Generating changelog for $(THIS_RELEASE) from $(LAST_RELEASE)..."
+	@echo
+	@changelog-build -last-release $(LAST_RELEASE) \
+		-entries-dir .changelog/ \
+		-changelog-template .changelog/changelog.tmpl \
+		-note-template .changelog/note.tmpl \
+		-this-release $(THIS_RELEASE)
+
+changelog-entry:
+	@changelog-entry -dir .changelog/
+	
+
 test: fmtcheck
 	go test $(TEST) -v || exit 1
 	echo $(TEST) | \
@@ -109,4 +128,4 @@ website-lint:
 	@echo "==> Checking for broken links..."
 	@scripts/markdown-link-check.sh "$(DOCKER)" "$(DOCKER_RUN_OPTS)" "$(DOCKER_VOLUME_OPTS)" "$(PROVIDER_DIR_DOCKER)"
 
-.PHONY: build test testacc testrace cover vet fmt fmtcheck errcheck test-compile packages clean website-lint
+.PHONY: build test testacc testrace cover vet fmt fmtcheck errcheck test-compile packages clean website-lint changelog changelog-entry