Add initial CI workflow

.github/workflows/ci.yml

@@ -0,0 +1,71 @@
+name: Continuous Integration
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+      - 'releases/*'
+
+jobs:
+  test-docker:
+    name: Docker Tests
+    runs-on: ubuntu-latest
+
+    # Run a local registry to push to
+    services:
+      registry:
+        image: registry:2
+        ports:
+          - 5001:5000
+
+    env:
+      TEST_TAG: localhost:5001/actions/container-action:latest
+
+    steps:
+      - name: Checkout
+        id: checkout
+        uses: actions/checkout@v3
+
+      - name: Setup Docker BuildX
+        id: setup-buildx
+        uses: docker/setup-buildx-action@v2
+        with:
+          install: true
+          driver-opts: network=host
+
+      - name: Build the Container
+        id: build
+        uses: docker/build-push-action@v4
+        with:
+          context: .
+          push: true
+          tags: ${{ env.TEST_TAG }}
+
+      - name: Run the Container
+        id: run
+        env:
+          INPUT_WHO_TO_GREET: Mona Lisa Octocat
+        run: |
+          docker run \
+            --env INPUT_WHO_TO_GREET="Mona Lisa Octocat" \
+            --rm ${{ env.TEST_TAG }}
+
+  test-action:
+    name: GitHub Actions Test
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        id: checkout
+        uses: actions/checkout@v3
+
+      - name: Test Local Action
+        id: test-action
+        uses: ./
+        with:
+          who-to-greet: Mona Lisa Octocat
+
+      - name: Print Output
+        id: output
+        run: echo "${{ steps.test-action.outputs.greeting }}"