Setting up dGraph with NodeJS and Express?

[Carrein (Addison Ho)]

I have Docker, the JS client and dgraph setup fine on a server instance per the guides.
I have also setup a sample node web app instance using Express (also by tutorial)

I tried to mesh the two together to see if i can get a RESTful request to query the database…

'use strict';

const express = require('express');
const dgraph = require("dgraph-js");
const grpc = require("grpc");

// Constants
const PORT = 8080;
const HOST = '0.0.0.0';

// App
const app = express();
app.get('/', (req, res) => {
  res.send('Hello world\n');
});

app.get('/sample', async function (req, res, next) {
  console.log('Accessing the secret section ...')
    const dgraphClientStub = newClientStub();
    const dgraphClient = newClient(dgraphClientStub);
    
    await setSchema(dgraphClient);
    dgraphClientStub.close();
    res.send('Entered\n');
})

// Create a client stub.
function newClientStub() {
    return new dgraph.DgraphClientStub("localhost:9080", grpc.credentials.createInsecure());
}

// Create a client.
function newClient(clientStub) {
    return new dgraph.DgraphClient(clientStub);
}

// Set schema.
async function setSchema(dgraphClient) {
    const schema = `
        name: string @index(exact) .
        age: int .
        married: bool .
        loc: geo .
        dob: datetime .
    `;
    const op = new dgraph.Operation();
    op.setSchema(schema);
    await dgraphClient.alter(op);
}

app.listen(PORT, HOST);
console.log(`Running on http://${HOST}:${PORT}`);

This didn’t work of course.

Running on http://0.0.0.0:8080
Accessing the secret section ...
(node:17) UnhandledPromiseRejectionWarning: Error: 14 UNAVAILABLE: failed to connect to all addresses
    at Object.exports.createStatusError (/usr/src/app/node_modules/grpc/src/common.js:91:15)
    at Object.onReceiveStatus (/usr/src/app/node_modules/grpc/src/client_interceptors.js:1204:28)
    at InterceptingListener._callNext (/usr/src/app/node_modules/grpc/src/client_interceptors.js:568:42)
    at InterceptingListener.onReceiveStatus (/usr/src/app/node_modules/grpc/src/client_interceptors.js:618:8)
    at callback (/usr/src/app/node_modules/grpc/src/client_interceptors.js:845:24)
(node:17) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:17) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

I would appreciate if someone could guide me in the right direction or if I’m way off already.

[MichelDiz]

I’ve tested here and all is working. Maybe the addr isn’t exposed.
Instead of localhost:9080 try “DockerMachineIP:9080”

[Carrein (Addison Ho)]

Thanks for the reply! That’s exactly right, setting the IP to the server instance IP fixed it.