NodeJS Express API Client network socket connection issue in Docker

Drivers & Stacks Javascript
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#1

I'm building an express api in front of a neo4j database. The whole project runs two services in docker:

  1. neo4j-database
  2. characters-api

I use an .env file to set all environment variables, hence the mapping in the docker-compose.yml.

Both are connected through a network called "neo4j-database-nw". Express (by default creation with the "express-generator") has the myapp/bin/www file as entrypoint. This is where I create my neo4j driver instance, which I also added to the export of the module, as the driver shall be available throughout the application.
When I create a controller for a route (e.g. /test) and and create a session in that module, which then runs a simple query, I get the following error: "Neo4jError: Client network socket disconnected before secure TLS connection was established".
In the myapp/bin/www file I create the driver with the following parameters:
const neo4jDriver = neo4j.driver(bolt://neo4j-database:7687, neo4j.auth.basic(neo4j, test));
And I close the driver not earlier than with the terminus package during the "onSignal" event, which is, when the application receives one of the following signals "['SIGTERM', 'SIGINT']".
What am I missing to establish a connection with the database from my nodejs application?

myapp/controllers/test/testController.ts:

import Debug from 'debug';
import express from 'express';
import { neo4jDriver } from '../../bin/www';

const debug = Debug('neo4j:session');
const router = express.Router();

/* GET users listing. */
router.get('/', async (req, res, next) => {
  const query = 'CREATE (c:Character) SET c.name = {name} RETURN c';

  const params = {};

  const session = neo4jDriver.session();

  try {
    const result = await session.run(query, params);
    res.status(200).send(result);
  } catch (error) {
    debug(`Unable to execute query. ${error}`);
    res.status(500).send(error);
  } finally {
    session.close();
  }
});

export default router;

docker-compose.yml:

version: "3.7"
services:
  characters-api:
    image: characters-api:latest
    container_name: characters-api
    build: .
    depends_on:
      - neo4j-database
    command: sh -c 'sh ./install-dependencies.sh && ./node_modules/.bin/tsc-watch --project ./tsconfig.json --skipLibCheck --noClear --onSuccess "npm run compile-and-run"'
    environment:
      NEO4J_API_CONTAINER_PORT: ${NEO4J_API_CONTAINER_PORT}
      NEO4J_API_HOST_PORT: ${NEO4J_API_HOST_PORT}
      NEO4J_USERNAME: ${NEO4J_USERNAME}
      NEO4J_PASSWORD: ${NEO4J_PASSWORD}
      NEO4J_DATABASE: ${NEO4J_DATABASE}
      NEO4J_BOLT_PORT: ${NEO4J_BOLT_PORT}
      NEO4J_HOSTNAME: ${NEO4J_HOSTNAME}
    ports:
      - ${NEO4J_API_HOST_PORT}:${NEO4J_API_CONTAINER_PORT}
    volumes:
      - .:/usr/src/app
    networks: 
      - neo4j-database-nw
  neo4j-database:
    image: neo4j:4.0.0
    container_name: neo4j-database
    environment:
      NEO4J_AUTH: ${NEO4J_AUTH}
    ports:
      - 7474:7474
      - 7473:7473
      - 7687:7687
    volumes:
      - ./neo4j-database/data:/data
      - ./neo4j-database/logs:/logs
      - ./neo4j-database/import:/var/lib/neo4j/import
      - ./neo4j-database/plugins:/plugins
    networks: 
      - neo4j-database-nw
networks: 
  neo4j-database-nw:
#2

Please show what's behind this code, and indicate which version of the JS driver you're using.

#3

I'm using "neo4j-driver": "^1.7.6", as well as node:12.15.0 and neo4j:4.0.0.
I've googled a lot and only found a similar issue, where the driver/session was closed before the application and the database had the chance to establish the TLS connection. But this doesn't seem to be the case here, i think.

../../bin/www:

#!/usr/bin/env node
'use strict';

/**
 * Module dependencies.
 * @private
 */

import { createTerminus, TerminusOptions } from '@godaddy/terminus';
import dotenv from 'dotenv';
import { createServer } from 'http';
import neo4j from 'neo4j-driver';
import app from '../app';
import { onError, onListening } from './helpers/expressEventHandlers';
import { normalizePort } from './helpers/normalizePort';
import { onSignal } from './helpers/terminusHandlers';

/**
 * Get environment variables.
 */

dotenv.config();
const neo4jHostname = process.env.NEO4J_HOSTNAME!;
const neo4jBoltPort = process.env.NEO4J_BOLT_PORT!;
const neo4jUsername = process.env.NEO4J_USERNAME!;
const neo4jPassword = process.env.NEO4J_PASSWORD!;

/**
 * Create the neo4j database driver.
 */

const neo4jDriver = neo4j.driver(`bolt://${neo4jHostname}:${neo4jBoltPort}`, neo4j.auth.basic(neo4jUsername, neo4jPassword));

/**
 * Get the port from environment and store it in Express.
 */

const port = normalizePort(process.env.NEO4J_API_CONTAINER_PORT || '3000');
app.set('port', port);

/**
 * Create the HTTP server.
 */

const server = createServer(app);

/**
 * Set the Terminus options
 */

const terminusOptions: TerminusOptions = {
  onSignal,
  signals: ['SIGTERM', 'SIGINT']
};

createTerminus(server, terminusOptions);

/**
 * Listen on provided port, on all network interfaces.
 */

server.listen(port);
server.on('error', onError);
server.on('listening', onListening);

/**
 * Module exports.
 * @public
 */

export {
  port,
  server,
  neo4jDriver
};

And the .env file:

NEO4J_CONLIMIT='50'
NEO4J_HOSTNAME=neo4j-database
NEO4J_HTTP_PORT=7474
NEO4J_HTTPS_PORT=7473
NEO4J_BOLT_PORT=7687
NEO4J_AUTH=neo4j/test
NEO4J_USERNAME=neo4j
NEO4J_PASSWORD=test
NEO4J_DATABASE='neo4j'
NEO4J_API_HOST_PORT=3000
NEO4J_API_CONTAINER_PORT=3000
NEO4J_API_DEBUG_PORT=9229
#4

I think a thing to try here is to use v1. We're in the midst of some major updates to our client drivers & neo4j itself with version 4. Usually people do this:

const neo4j = require('neo4j-driver').v1

Or in your case:

import { v1 as neo4j } from 'neo4j-driver';

When using the older driver. What you're doing there looks legitimate for the new driver for 4.0 though, but that's not the version you're using.

#5

Hey Daniel, thank you for your help. I just updated the neo4j-driver to the latest version (4.0.1) and that did the trick...
The ^ semver marker in my package.json kept the package from upgrading to the latest major version.

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