CI: add release comms workflow (#89718)

* add release comms workflow

* add version input

* Add release-comms workflow to CODEOWNERS

.github/CODEOWNERS

@@ -673,6 +673,7 @@ embed.go @grafana/grafana-as-code
 /.github/workflows/bump-version.yml @grafana/grafana-release-guild
 /.github/workflows/close-milestone.yml @grafana/grafana-release-guild
 /.github/workflows/release-pr.yml @grafana/grafana-release-guild
+/.github/workflows/release-comms.yml @grafana/grafana-release-guild
 /.github/workflows/codeowners-validator.yml @tolzhabayev
 /.github/workflows/codeql-analysis.yml @DanCech
 /.github/workflows/commands.yml @torkelo

.github/workflows/release-comms.yml

@@ -0,0 +1,36 @@
+# This workflow runs whenever the release PR is merged. It includes post-release communication processes like
+# posting to slack, the website, community forums, etc.
+# Only things that happen after a release is completed and all of the necessary code changes (like the changelog) are made.
+name: Post-release
+on:
+  workflow_dispatch:
+    inputs:
+      dry_run:
+        required: false
+        default: true
+      version:
+        required: true
+  pull_request:
+    types:
+      - closed
+    branches:
+      - 'main'
+      - 'v*.*.*'
+jobs:
+  post_release:
+    name: Post-release comms
+    env:
+    steps:
+      - if: github.event.workflow_dispatch
+        run: |
+          echo "VERSION=${{ inputs.version }}" >> $GITHUB_ENV
+          echo "DRY_RUN=${{ inputs.dry_run }}" >> $GITHUB_ENV
+      - if: github.event.pull_request.merged == true && startsWith(github.head_ref, 'release/')
+        run: |
+          echo "VERSION=$(echo ${{ github.head_ref }} | sed -e 's/release\///g')" >> $GITHUB_ENV
+          echo "DRY_RUN=false" >> $GITHUB_ENV
+      - run: "echo push-grafana-tag $VERSION (dry run: $DRY_RUN)"
+      - run: "echo post changelog to forums for $VERSION (dry run: $DRY_RUN)"
+      - run: "echo create github release"
+      - run: "echo publish docs for $VERSION (dry run: $DRY_RUN)"
+      - run: "announce on slack that $VERSION has been released (dry run: $DRY_RUN)"