demo-grpc-web-vite-issue

A simplist demo to show the issue when using vite with grpc-web generated code.

Btw, don't need the server and proxy to run to see the error in the web service. Need server and proxy when web service is running the test the grpc service itself.

UPDATE: 2022-07-04 Demo is working!

Quick Launch

• server

cd server

npm install

node echo_server.js

• envoy proxy

# ubuntu
docker build -t yg-envoy-grpc -f Dockerfile .
docker run --rm -it -p 9090:9090 -p 9901:9901 --network=host yg-envoy-grpc

• client

cd client

npm install

npm run dev

Move to web browser to see the demo.

Quick Start

Env

$ nvm -v
0.37.0

$ node -v
v16.15.0

$ npm -v
8.5.5

$ vue -V
@vue/cli 5.0.4

$ protoc --version
libprotoc 3.6.1

Launch grpc server in Node

cd server

npm install

node echo_server.js

Test the server using node, open another terminal, same directory

node echo_client_static.js

Launch envoy proxy

This proxy is using envoy v1.10.0, later version requires a different setting. The settings are different in Ubuntu and Mac/Win, see the note in directory @/proxy/envoy.yaml.

• ubuntu

docker build -t yg-envoy-grpc -f Dockerfile .
docker run --rm -it -p 9090:9090 -p 9901:9901 --network=host yg-envoy-grpc

• mac/win

# change file envoy.yaml
...
  # macos/windows 
  # envoy is running within docker
  # grpc service aka node-server or python-server is running in host
  # direct request from web to envoy to server by host.docker.internal
  hosts: [{ socket_address: { address: host.docker.internal, port_value: 50051 }}]
  # ubuntu/linux
  # use --network=host which is depreciated
  # docker run --rm -it -p 9090:9090 -p 9901:9901 --network=host yg-envoy-echo
  # hosts: [{ socket_address: { address: 0.0.0.0, port_value: 50051 }}]
...

docker build -t yg-envoy-grpc -f Dockerfile .

docker run --rm -it -p 9090:9090 -p 9901:9901 yg-envoy-grpc

Note: Tested on ubuntu and mac only.

Using grpc-web with Vite

cd client

npm install

npm run dev

Issue

IMHO, the issue is rooted as Vite not support commonjs by nature, while grpc-web can (only?) compile the proto file to commonjs in some sense.

Here are the details:

• Generate grpcweb code following https://github.com/grpc/grpc-web

cd proto

protoc -I=. echo.proto \
  --js_out=import_style=commonjs:../client/src/proto/protoc-js \
  --grpc-web_out=import_style=commonjs,mode=grpcwebtext:../client/src/proto/protoc-js

• Use it in App.vue

  ...
  messages = require('./proto/protoc-js/echo_pb')
  services = require('./proto/protoc-js/echo_grpc_web_pb')

  const client = new services.EchoServiceClient('http://127.0.0.1:9090')
  const request = new messages.EchoRequest()
  ...

• Error (see in browser):

Uncaught ReferenceError: require is not defined

Solution 1, not working, require, exports not defined

Try to enable Vite to support grpc-web auto-generated commonjs code.

Edit the vite.config.js file to enable Vite to support commonjs?

cd client

npm install @originjs/vite-plugin-commonjs --save-dev

• in vite.config.js file:

import { viteCommonjs } from '@originjs/vite-plugin-commonjs'

export default {
    plugins: [
        viteCommonjs()
    ]
}

npm run dev

Error:

Uncaught ReferenceError: __require_for_vite_FubgTC is not defined

If further edit the App.vue with

// solution 1, vite.config.js
import * as __require_for_vite_FubgTC from './proto/protoc-js/echo_pb';
import * as __require_for_vite_bhjJLN from './proto/protoc-js/echo_grpc_web_pb';

messages = __require_for_vite_FubgTC.default || __require_for_vite_FubgTC
services = __require_for_vite_bhjJLN.default || __require_for_vite_bhjJLN

const client = new services.EchoServiceClient('http://127.0.0.1:9090')
const request = new messages.EchoRequest()

Then, error:

Uncaught ReferenceError: exports is not defined

Solution 2, not working, circular structure JSON

Several reports said https://github.com/timostamm/protobuf-ts works fine with Vite, like

grpc/grpc-web#535 grpc/grpc-web#1242 https://zenn.dev/emiksk/articles/883d8b333ffb26

Unfortunately, I found trouble.

• Get protobuf-ts and use it to generate ts file

cd client

npm install @protobuf-ts/plugin @protobuf-ts/grpcweb-transport

npx protoc --ts_out ./src/proto/protobuf-ts --proto_path ../proto ../proto/echo.proto

• Use it in App.vue

import { EchoRequest } from './proto/protobuf-ts/echo'
import { EchoServiceClient } from './proto/protobuf-ts/echo.client'

const client = new EchoServiceClient('http://127.0.0.1:9090')
const request = EchoRequest.fromJson({"query": "Hello Vite!"})

Error:

shared.esm-bundler.js:453 Uncaught TypeError: Converting circular structure to JSON

Solution 3, not working, ..

Tried to use the protoc-gen-grpc-web to generage ts code, the issue is that js_out can only generate with option import_style=commonjs

cd proto

protoc -I=. echo.proto \
  --js_out=import_style=commonjs:../client/src/proto/protoc-ts \
  --grpc-web_out=import_style=typescript,mode=grpcweb:../client/src/proto/protoc-ts

• in App.vue

import { EchoRequest } from './proto/protoc-ts/echo_pb.d.ts'
import { EchoServiceClient } from './proto/protoc-ts/EchoServiceClientPb.ts'

const client = new EchoServiceClient('http://127.0.0.1:9090')
const request = EchoRequest

Error: Uncaught ReferenceError: exports is not defined

This is the same error as in the last step of solution 1.

Conclusion

Solution 1 seems the most promising and most useful, as it enables the vite to support commonjs, in my view.

Solution 2 seems only applicable to grpc-web itself.

The ideal solution could be grpc-web to enable js_out=import_style=typescript, but don't know it is in the roadmap.