Adding Spring demo application

.github/workflows/build-demo-app.yaml

@@ -0,0 +1,45 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Build Demo App
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'demo-app/**'
+  pull_request:
+    branches:
+      - main
+    paths:
+      - 'demo-app/**'
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./demo-app
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Set up JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'zulu'
+      - name: Build
+        run: mvn --batch-mode --update-snapshots package
+

.github/workflows/build.yml

@@ -17,9 +17,13 @@ on:
   push:
     branches:
       - main
+    paths-ignore:
+      - 'demo-app/**'
   pull_request:
     branches:
       - main
+    paths-ignore:
+      - 'demo-app/**'
 
 jobs:
   build:

.github/workflows/release-demo-app.yaml

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+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Spring Rest JPA Release
+on:
+  push:
+    tags:
+      - "demo-app/v*"
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: ./demo-app
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Set up JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'zulu'
+      - name: Build
+        run: mvn --batch-mode --update-snapshots package
+      - name: Docker login
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Version from tag
+        id: version-from-tag
+        run: echo version=${GITHUB_REF_NAME//demo-app\/} >> $GITHUB_OUTPUT
+      - name: Docker Extract metadata
+        id: meta
+        uses: docker/metadata-action@v4
+        with:
+          images: ghcr.io/google/spring-demo-app
+          tags: |
+            type=semver,pattern={{major}}.{{minor}}.{{patch}},value=${{ steps.version-from-tag.outputs.version }}
+      - name: Docker build and push
+        uses: docker/build-push-action@v4
+        with:
+          context: ./demo-app
+          file: ./demo-app/Dockerfile
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

demo-app/Dockerfile

@@ -0,0 +1,19 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM azul/zulu-openjdk-alpine:17-latest
+VOLUME /tmp
+ARG JAR_FILE=target/*.jar
+COPY ${JAR_FILE} app.jar
+ENTRYPOINT ["sh", "-c", "java ${JAVA_OPTS} -jar /app.jar ${0} ${@}"]

demo-app/README.md

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+# spring-demo-app
+
+The folder contains source code of a simple Java application that uses Spring Boot framework
+and exposes the REST endpoint. The data is fetched from the relational database with
+Java Persistence API.
+
+## Usage
+
+The service exposes below endpoints:
+
+* `/books` returns collection of books
+
+In the addition to above, Spring Boot actuator endpoints are exposed per configuration.
+
+### Source code
+
+Prerequisites:
+
+* [JDK](https://openjdk.org/projects/jdk/17/) 17 or newer
+* [Maven](https://maven.apache.org/download.cgi)
+
+Build application from the source code.
+
+```sh
+mvn package
+java -jar target/spring-demo-app-0.0.1-SNAPSHOT.jar
+```
+
+### Container image
+
+1. Adjust `application.yaml` according to your needs
+2. Run the container
+
+   ```sh
+   docker run -d  --name spring-demo-app \
+      -p 8080:8080 \
+      -v "`pwd`/application.yaml:/application.yaml" \
+      ghcr.io/google/spring-demo-app:latest 
+   ```
+
+### Kubernetes
+
+1. Adjust `application.yaml` according to your needs
+2. Adjust `kustomization.yaml` according to your needs
+3. Customize and apply Kubernetes manifests
+
+   ```sh
+   kubectl kustomize | kubectl apply -f
+   ```

demo-app/application.yaml

@@ -0,0 +1,32 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+spring:
+  datasource:
+    url: jdbc:h2:mem:mydb
+    username: sa
+    password: password
+    driverClassName: org.h2.Driver
+  jpa:
+    hibernate:
+      ddl-auto: create
+    database-platform: org.hibernate.dialect.H2Dialect
+    defer-datasource-initialization: true
+management:
+  endpoints:
+    web:
+      exposure:
+        include:
+          - health
+          - prometheus

demo-app/examples/spring-demo-app-gmp.yaml

@@ -0,0 +1,26 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+apiVersion: monitoring.googleapis.com/v1
+kind: PodMonitoring
+metadata:
+  name: spring-demo-app
+spec:
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: spring-demo-app
+  endpoints:
+  - port: http
+    path: /actuator/prometheus
+    interval: 5s

demo-app/examples/spring-demo-app.yaml

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+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: spring-demo-app
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: spring-demo-app
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: spring-demo-app
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: spring-demo-app
+    spec:
+      serviceAccountName: spring-demo-app
+      containers:
+      - name: spring-demo-app
+        image: ghcr.io/google/spring-demo-app:latest
+        args:
+        - --spring.config.location=file:/config/application.yaml
+        env:
+        - name: JAVA_OPTS
+          value: -XX:MaxRAMPercentage=75
+        volumeMounts:
+        - name: spring-demo-app-config
+          mountPath: /config
+        ports:
+        - name: http
+          containerPort: 8080
+        startupProbe:
+          periodSeconds: 2
+          failureThreshold: 60
+          httpGet:
+            path: /actuator/health
+            port: http
+            scheme: HTTP
+        livenessProbe:
+          httpGet:
+            path: /actuator/health
+            port: http
+            scheme: HTTP
+        resources:
+          limits:
+            cpu: "1"
+            memory: 512Mi
+          requests:
+            cpu: 500m
+            memory: 512Mi
+      volumes:
+      - name: spring-demo-app-config
+        configMap:
+          name: spring-demo-app-config
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: spring-demo-app
+spec:
+  selector:
+    app.kubernetes.io/name: spring-demo-app
+  ports:
+  - port: 8080
+    targetPort: http

demo-app/kustomization.yaml

@@ -0,0 +1,28 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+- examples/spring-demo-app.yaml
+# Uncomment for Google Managed Prometheus metrics scraping
+#- examples/spring-app-demo-gmp.yaml
+
+namespace: demo
+
+configMapGenerator:
+- name: spring-demo-app-config
+  files:
+  - application.yaml