Add release action, update README

Author: migesok

.github/workflows/release.yml

@@ -0,0 +1,50 @@
+name: release
+
+on:
+  push:
+    tags: [ "v*" ]
+
+# run only one release action at a time for the repo, wait for the previous to finish before running another one
+concurrency:
+  group: ${{ github.repository }}-${{ github.workflow }}
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          # Fetch all history for all branches and tags - just in case it's all necessary for ci-release.
+          # Tags are needed for versionPolicyCheck binary and source compat checks.
+          fetch-depth: 0
+      - uses: coursier/cache-action@v6
+      - uses: actions/setup-java@v5
+        with:
+          java-version: 17
+          distribution: temurin
+          cache: sbt
+      - uses: sbt/setup-sbt@v1
+      # sbt ci-release doesn't verify the build, need to do it explicitly
+      - name: sbt build
+        run: sbt clean build
+      - run: sbt ci-release
+        env:
+          PGP_PASSPHRASE: ${{ secrets.PGP_PASSPHRASE }}
+          PGP_SECRET: ${{ secrets.PGP_SECRET }}
+          SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
+          SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
+
+      - name: delete release tag if failed
+        if: failure()
+        run: git push --delete origin ${{ github.ref_name }}
+
+      - name: publish release notes
+        if: success()
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          tag: ${{ github.ref_name }}
+        run: |
+          gh release create "$tag" \
+              --repo="$GITHUB_REPOSITORY" \
+              --title="v${tag#v}" \
+              --generate-notes

README.md

@@ -10,7 +10,7 @@ The minimum supported JDK version is 17.
 ## Table of Contents
 
 - [Modules](#modules)
-  - [k8s-dns-name-resolver](#k8s-dns-name-resolver)
+    - [k8s-dns-name-resolver](#k8s-dns-name-resolver)
 - [For Contributors](#for-contributors)
 
 ## Modules
@@ -88,3 +88,27 @@ A full build can be run with:
 ```shell
 sbt build
 ```
+
+### How to Make a Release
+
+- Being on the up-to-date main branch, create a release tag:
+
+```shell
+git tag v1.2.3
+```
+
+- Push the tag:
+
+```shell
+git push origin v1.2.3
+```
+
+- This will trigger the release GitHub Action.
+  If it succeeds, the release ends up on Maven Central with GitHub release notes generated
+  automatically from PRs info.
+- If the release GitHub Action fails, the tag will be deleted on remote.
+  After deleting the tag locally, fix the main branch and do the process again:
+
+```shell
+git tag -d v1.2.3
+```