Merge pull request #3046 from zarinn3pal/feat/health_check_example

feat: Added health check example

Author: murgatroid99

examples/health_check/README.md

@@ -0,0 +1,41 @@
+# Health Check
+
+This example demonstrates how to set up standard gRPC Health Checks utilizing the unified [grpc-health-check](https://www.npmjs.com/package/grpc-health-check) library.
+
+## Overview
+
+The example uses the `grpc-health-check` package to:
+- **Server**: Initialize a `HealthImplementation` and toggle the health status every 3 seconds.
+- **Client**: Connect to the server and `watch` the health service for streamed status updates.
+
+## Start the server
+
+Run the server, which serves only the health checking API:
+
+```
+node server.js
+```
+
+## Run the client
+
+In another terminal, run the client which watches the server for health check variations:
+
+```
+node client.js
+```
+
+## Expected Output
+
+The client will begin to continuously receive state changes from the server:
+
+**Server Output:**
+```
+Server running at http://0.0.0.0:50051
+```
+
+**Client Output:**
+```
+Health check status: SERVING
+Health check status: NOT_SERVING
+Health check status: SERVING
+```

examples/health_check/client.js

@@ -0,0 +1,51 @@
+/*
+ *
+ * Copyright 2026 gRPC authors.
+ *
+ * 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
+ *
+ *     http://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.
+ *
+ */
+
+const grpc = require('@grpc/grpc-js');
+const protoLoader = require('@grpc/proto-loader');
+const { protoPath: HEALTH_PROTO_PATH } = require('grpc-health-check');
+
+const packageDefinition = protoLoader.loadSync(
+  HEALTH_PROTO_PATH,
+  {keepCase: true,
+   longs: String,
+   enums: String,
+   defaults: true,
+   oneofs: true
+  });
+const healthProto = grpc.loadPackageDefinition(packageDefinition).grpc.health.v1;
+
+function main() {
+  const healthClient = new healthProto.Health('localhost:50051', grpc.credentials.createInsecure());
+
+  const watchStream = healthClient.watch({ service: '' });
+
+  watchStream.on('data', function (response) {
+    console.log(`Health check status: ${response.status}`);
+  });
+
+  watchStream.on('error', function (error) {
+    console.error('Health check error:', error.message);
+  });
+
+  watchStream.on('end', function () {
+    console.log('Health check stream ended.');
+  });
+}
+
+main();

examples/health_check/server.js

@@ -0,0 +1,47 @@
+/*
+ *
+ * Copyright 2026 gRPC authors.
+ *
+ * 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
+ *
+ *     http://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.
+ *
+ */
+
+const grpc = require('@grpc/grpc-js');
+const { HealthImplementation } = require('grpc-health-check');
+
+/**
+ * Starts an RPC server that toggles health checks status.
+ */
+function main() {
+  const server = new grpc.Server();
+
+  // Set up the health check service
+  const statusMap = {
+    '': 'SERVING',
+  };
+  const healthImpl = new HealthImplementation(statusMap);
+  healthImpl.addToServer(server);
+
+  // Toggle the health status continuously
+  let nextStatus = 'NOT_SERVING';
+  setInterval(() => {
+    healthImpl.setStatus('', nextStatus);
+    nextStatus = nextStatus === 'SERVING' ? 'NOT_SERVING' : 'SERVING';
+  }, 3000);
+
+  server.bindAsync('0.0.0.0:50051', grpc.ServerCredentials.createInsecure(), () => {
+    console.log('Server running at http://0.0.0.0:50051');
+  });
+}
+
+main();

examples/package.json

@@ -8,6 +8,7 @@
     "@grpc/grpc-js": "^1.10.2",
     "@grpc/grpc-js-xds": "^1.10.0",
     "@grpc/reflection": "^1.0.0",
+    "grpc-health-check": "^2.1.0",
     "@q42philips/node-grpc-error-details": "^2.1.0",
     "lodash": "^4.6.1",
     "minimist": "^1.2.0"