Add release workflows (opensearch-project#188)

Signed-off-by: Sayali Gaikawad <gaiksaya@amazon.com>

Author: gaiksaya

.github/workflows/release-drafter.yml

@@ -0,0 +1,40 @@
+name: Draft Release
+
+on:
+  push:
+    tags:
+      - "*"
+
+jobs:
+  draft_release:
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+      contents: write
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v3
+      - name: Install Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: jruby
+      - name: Configure AWS credentials
+        uses: aws-actions/configure-aws-credentials@v1
+        with:
+          role-to-assume: ${{ secrets.GET_SECRET_IAM_ROLE }}
+          aws-region: us-east-1
+      - name: Download signing key
+        run: | 
+          aws secretsmanager get-secret-value --secret-id jenkins-opensearchproject-rubygems-private-key --query SecretString --output text > gem-private_key.pem
+      - name: Build and package gem artifact
+        run: |
+          gem build logstash-output-opensearch.gemspec
+          mkdir dist && mv logstash-output-opensearch-*.gem dist/
+          tar -cvf artifacts.tar.gz dist
+      - name: Draft a release
+        uses: softprops/action-gh-release@v1
+        with:
+          draft: true
+          generate_release_notes: true
+          files: |
+            artifacts.tar.gz

RELEASING.md

@@ -33,4 +33,8 @@ Repositories create consistent release labels, such as `v1.0.0`, `v1.1.0` and `v
 
 The release process is standard across repositories in this org and is run by a release manager volunteering from amongst [MAINTAINERS](MAINTAINERS.md).
 
-TODO
+1. Create a tag, e.g. 1.0.0, and push it to this GitHub repository.
+1. The [release-drafter.yml](.github/workflows/release-drafter.yml) will be automatically kicked off and a draft release will be created.
+1. This draft release triggers the [jenkins release workflow](https://build.ci.opensearch.org/job/logstash-ouput-opensearch-release) as a As a result of which the logstash-output-plugin is released on [rubygems.org](https://rubygems.org/gems/logstash-output-opensearch). Please note that the release workflow is triggered only if created release is in draft state.
+1. Once the above release workflow is successful, the drafted release on GitHub is published automatically.
+1. Increment "version" in [logstash-output-opensearch.gemspec](./logstash-output-opensearch.gemspec) to the next iteration, e.g. 1.0.1.

jenkins/release.jenkinsFile

@@ -0,0 +1,12 @@
+lib = library(identifier: 'jenkins@1.4.2', retriever: modernSCM([
+    $class: 'GitSCMSource',
+    remote: 'https://github.com/opensearch-project/opensearch-build-libraries.git',
+]))
+
+standardReleasePipelineWithGenericTrigger(
+    tokenIdCredential: 'jenkins-logstash-output-opensearch-generic-webhook-token',
+    causeString: 'A tag was cut on opensearch-project/logstash-output-opensearch repository causing this workflow to run',
+    downloadReleaseAsset: true,
+    publishRelease: true) {
+        publishToRubyGems(apiKeyCredentialId: 'jenkins-logstash-output-opensearch-api-key')
+    }