This library provides a way to instrument Node.js gRPC clients and servers with interceptors/middleware. Server-side interceptors are [not yet implemented](https://github.com/grpc/grpc-node/issues/419) in grpc for node. This library is a temporary fix fo
npm install grpcjs-interceptors
npm install git+https://github.com/mfecteau34/node-grpc-interceptors.git
`
$3
This usage example takes for granted that two RPC metadata parameters are sent with the RPC call. One parameter is "user", and the other "password".
If using the grpcurl utility for testing, add those parameters in the command line : -rpc-header 'user: rpcuser' -rpc-header 'password: abc123'
Lodash is also used to get the parameters easily.
`js
const interceptors = require('grpc-interceptors');
const _ = require('lodash');
const server = interceptors.serverProxy(new grpc.Server());
server.addService(proto.MyPackage.MyService.service, { Method1, Method2 });
// Original version did not have "callback" as a parameter.
const myMiddlewareFunc = async function (ctx, next, callback) {
// do stuff before call
console.log('Making gRPC call...');
// Doing authentication
let user = _.get(ctx,'call.metadata._internal_repr.user[0]','undefined')
let password = _.get(ctx,'call.metadata._internal_repr.password[0]','undefined')
if (user == "rpcuser" && password == "abc123") {
// Executing the RPC call only if the authentication was successful
await next();
// do stuff after call
console.log(ctx.status.code);
} else {
// The whole point for this fork was to have access to callback function ...
callback(new Error("Unauthorized"));
}
}
server.use(myMiddlewareFunc);
``