Below is a very minimal gRPC Server in NodeJS.

greeter_server.js

var PROTO_PATH = __dirname   '/../../protos/helloworld.proto';
var grpc = require('@grpc/grpc-js');
var protoLoader = require('@grpc/proto-loader');
var packageDefinition = protoLoader.loadSync(
    PROTO_PATH,
    {keepCase: true,
     longs: String,
     enums: String,
     defaults: true,
     oneofs: true
    });
var hello_proto = grpc.loadPackageDefinition(packageDefinition).helloworld;

function sayHello(call, callback) {
  callback(null, {message: 'Hello '   call.request.name});
}

function main() {
  var server = new grpc.Server();
  server.addService(hello_proto.Greeter.service, {sayHello: sayHello});
  server.bindAsync('0.0.0.0:50051', grpc.ServerCredentials.createInsecure(), () => {
    server.start();
  });
}

main();

I was able to host the above server in Cloud Run and I was given a url to access the server which is of the form https://greeter-service-abcdefghij-ue.a.run.app.

Below is a client to connect to the server above.

greeter_client.js

var PROTO_PATH = __dirname   '/../../protos/helloworld.proto';

var parseArgs = require('minimist');
var grpc = require('@grpc/grpc-js');
var protoLoader = require('@grpc/proto-loader');
var packageDefinition = protoLoader.loadSync(
    PROTO_PATH,
    {keepCase: true,
     longs: String,
     enums: String,
     defaults: true,
     oneofs: true
    });
var hello_proto = grpc.loadPackageDefinition(packageDefinition).helloworld;

function main() {

  var target = 'localhost:50051'; //If I change this to greeter-service-abcdefghij-ue.a.run.app I get an error
  var client = new hello_proto.Greeter(target,
                                       grpc.credentials.createInsecure());
  var user='world';
  client.sayHello({name: user}, function(err, response) {
    console.log('Greeting:', response.message);
  });
}

main();

Everything works perfectly if I am running both the server and client on localhost but the moment I change the clients connection address from localhost:50051 to greeter-service-abcdefghij-ue.a.run.app I get the following error:

Error: 14 UNAVAILABLE: read ECONNRESET

Is there a specific way to connect to the server when it has been hosted?

Thank you

CodePudding user response：

One possible problem is that you are not binding the server to the right port. The Cloud Run documentation says

The only special requirement for a gRPC server running in Cloud Run is to listen at the port specified by the PORT environment variable