GitHub Actions workflow for publishing gem versions

.github/workflows/publish.yaml

@@ -0,0 +1,35 @@
+name: Publish Gem
+
+on:
+  push:
+    tags:
+      - "v[0-9]+.[0-9]+.[0-9]+"
+      - "v[0-9]+.[0-9]+.[0-9]+-rc[0-9]+"
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ruby-3.1
+          bundler-cache: true
+          bundler: default
+      - name: Check for RubyGems credentials
+        run: |
+          if [ -z "${RUBYGEMS_API_KEY}" ]; then
+            echo "Missing RUBYGEMS_API_KEY!"
+            exit 2
+          fi
+      - name: Configure RubyGems access
+        run: |
+          mkdir -p ~/.gem
+          touch ~/.gem/credentials
+          chmod 600 ~/.gem/credentials
+          echo ":rubygems_api_key: ${RUBYGEMS_API_KEY}" >> ~/.gem/credentials
+      - name: Build Ruby gem
+        run: gem build duffel_api.gemspec
+      - name: Publish Ruby gem
+        run: find . -name 'duffel_api-*.gem' -maxdepth 1 -exec gem push {} \;