Move Node healthchecks to gRPC

kubernetes-manifests/currencyservice.yaml

@@ -30,13 +30,11 @@ spec:
         - name: grpc
           containerPort: 7000
         readinessProbe:
-          periodSeconds: 5
-          tcpSocket:
-            port: 7000
+          exec:
+            command: ["/bin/grpc_health_probe", "-addr=:7000"]
         livenessProbe:
-          periodSeconds: 5
-          tcpSocket:
-            port: 7000
+          exec:
+            command: ["/bin/grpc_health_probe", "-addr=:7000"]
         resources:
           requests:
             cpu: 100m

kubernetes-manifests/paymentservice.yaml

@@ -29,13 +29,11 @@ spec:
         ports:
         - containerPort: 50051
         readinessProbe:
-          periodSeconds: 5
-          tcpSocket:
-            port: 50051
+          exec:
+            command: ["/bin/grpc_health_probe", "-addr=:50051"]
         livenessProbe:
-          periodSeconds: 5
-          tcpSocket:
-            port: 50051
+          exec:
+            command: ["/bin/grpc_health_probe", "-addr=:50051"]
         resources:
           requests:
             cpu: 100m

pb/demo.proto

@@ -120,6 +120,7 @@ message Address {
 service CurrencyService {
     rpc GetSupportedCurrencies(Empty) returns (GetSupportedCurrenciesResponse) {}
     rpc Convert(CurrencyConversionRequest) returns (Money) {}
+    rpc Check(Empty) returns (Empty) {}
 }
 
 // Represents an amount of money with its currency type.
@@ -156,6 +157,7 @@ message CurrencyConversionRequest {
 
 service PaymentService {
     rpc Charge(ChargeRequest) returns (ChargeResponse) {}
+    rpc Check(Empty) returns (Empty) {}
 }
 
 message CreditCardInfo {

src/currencyservice/Dockerfile

@@ -1,7 +1,9 @@
+FROM gcr.io/microservices-demo-app/grpc-health-probe:1.0 AS probe
 FROM node:8
 WORKDIR /usr/src/app
 COPY package*.json ./
 RUN npm install --only=production
 COPY . .
+COPY --from=probe   /bin/grpc_health_probe /bin/grpc_health_probe
 EXPOSE 7000
 CMD [ "node", "server.js" ]

src/currencyservice/client.js

@@ -49,10 +49,18 @@ client.getSupportedCurrencies({}, (err, response) => {
   }
 });
 
-client.convert(request, function (err, response) {
+client.convert(request, (err, response) => {
   if (err) {
     console.error(`Error in convert: ${err}`);
   } else {
     console.log(`Convert: ${_moneyToString(request.from)} to ${_moneyToString(response)}`);
   }
 });
+
+client.check({}, (err, response) => {
+  if (err) {
+    console.log(`Error in check: ${err}`);
+  } else {
+    console.log(`Health check successful!`);
+  }
+})

src/currencyservice/server.js

@@ -16,17 +16,17 @@
 
 require('@google-cloud/profiler').start({
   serviceContext: {
-      service: 'currencyservice',
-      version: '1.0.0'
+    service: 'currencyservice',
+    version: '1.0.0'
   }
 });
- require('@google-cloud/trace-agent').start();
- require('@google-cloud/debug-agent').start({
+require('@google-cloud/trace-agent').start();
+require('@google-cloud/debug-agent').start({
   serviceContext: {
     service: 'currencyservice',
     version: 'VERSION'
   }
-})
+});
 
 const path = require('path');
 const grpc = require('grpc');
@@ -116,8 +116,8 @@ function convert (call, callback) {
         nanos: euros.nanos * data[request.to_code]
       });
 
-      result.units = Math.floor(result.units)
-      result.nanos = Math.floor(result.nanos)
+      result.units = Math.floor(result.units);
+      result.nanos = Math.floor(result.nanos);
       result.currency_code = request.to_code;
 
       console.log(`conversion request successful`);
@@ -130,6 +130,13 @@ function convert (call, callback) {
   }
 }
 
+/**
+ * Endpoint for health checks
+ */
+function check (call, callback) {
+  callback(null);
+}
+
 /**
  * Starts an RPC server that receives requests for the
  * CurrencyConverter service at the sample server port
@@ -137,7 +144,7 @@ function convert (call, callback) {
 function main () {
   console.log(`Starting gRPC server on port ${PORT}...`);
   const server = new grpc.Server();
-  server.addService(shopProto.CurrencyService.service, {getSupportedCurrencies, convert});
+  server.addService(shopProto.CurrencyService.service, {getSupportedCurrencies, convert, check});
   server.bind(`0.0.0.0:${PORT}`, grpc.ServerCredentials.createInsecure());
   server.start();
 }

src/paymentservice/Dockerfile

@@ -1,3 +1,5 @@
+FROM gcr.io/microservices-demo-app/grpc-health-probe:1.0 AS probe
+
 FROM node:8
 
 WORKDIR /usr/src/app
@@ -8,6 +10,8 @@ RUN npm install --only=production
 
 COPY . .
 
+COPY --from=probe   /bin/grpc_health_probe /bin/grpc_health_probe
+
 EXPOSE 50051
 
 CMD [ "node", "index.js" ]

src/paymentservice/server.js

@@ -41,6 +41,10 @@ class HipsterShopServer {
     }
   }
 
+  static CheckHandler(call, callback) {
+    callback(null);
+  }
+
   listen() {
     this.server.bind(`0.0.0.0:${this.port}`, grpc.ServerCredentials.createInsecure());
     console.log(`PaymentService grpc server listening on ${this.port}`);
@@ -56,7 +60,7 @@ class HipsterShopServer {
         enums: String,
         defaults: true,
         oneofs: true,
-      },
+      }
     );
     const protoDescriptor = grpc.loadPackageDefinition(packageDefinition);
     const hipsterShopPackage = protoDescriptor.hipstershop;
@@ -69,7 +73,8 @@ class HipsterShopServer {
       service,
       {
         charge: HipsterShopServer.ChargeServiceHandler.bind(this),
-      },
+        check: HipsterShopServer.CheckHandler.bind(this)
+      }
     );
   }
 }