To run the Apollo GraphQL server using Unit:

  1. Install Unit with the unit-dev/unit-devel package. Next, install Unit’s unit-http package:

    # npm install -g --unsafe-perm unit-http
  2. Create your app directory, install Apollo, and link unit-http:

    $ mkdir -p /path/to/app/
    $ cd /path/to/app/
    $ npm install @apollo/server graphql
    # npm link unit-http
  3. Create the middleware module; let’s store it as /path/to/app/apollo.js. First, initialize the directory:

    $ cd /path/to/app/
    $ npm init

    Next, add the following code:

    import { ApolloServer } from '@apollo/server';
    import { expressMiddleware } from '@apollo/server/express4';
    import { ApolloServerPluginDrainHttpServer } from '@apollo/server/plugin/drainHttpServer';
    import express from 'express';
    import http from 'http';
    import cors from 'cors';
    import bodyParser from 'body-parser';
    //import { typeDefs, resolvers } from './schema';
    const typeDefs = `#graphql
      type Query {
        hello: String
    // A map of functions which return data for the schema.
    const resolvers = {
      Query: {
        hello: () => 'world',
    // Required logic for integrating with Express
    const app = express();
    // Our httpServer handles incoming requests to our Express app.
    // Below, we tell Apollo Server to "drain" this httpServer,
    // enabling our servers to shut down gracefully.
    const httpServer = http.createServer(app);
    // Same ApolloServer initialization as before, plus the drain plugin
    // for our httpServer.
    const server = new ApolloServer({
      plugins: [ApolloServerPluginDrainHttpServer({ httpServer })],
    // Ensure we wait for our server to start
    await server.start();
    // Set up our Express middleware to handle CORS, body parsing,
    // and our expressMiddleware function.
      // expressMiddleware accepts the same arguments:
      // an Apollo Server instance and optional configuration options
      expressMiddleware(server, {
        context: async ({ req }) => ({ token: req.headers.token }),
    // Modified server startup; port number is overridden by Unit config
    await new Promise((resolve) => httpServer.listen({ port: 80 }, resolve));

    Make sure your package.json resembles this (mind “type”: “module”):

        "name": "unit-apollo",
        "version": "1.0.0",
        "description": "Running Apollo over Express on Unit",
        "main": "index.js",
        "type": "module",
        "scripts": {
            "test": "echo \"Error: no test specified\" && exit 1"
        "author": "Unit Team",
        "license": "ISC",
        "dependencies": {
            "@apollo/server": "^4.7.5",
            "apollo-server": "^3.12.0",
            "body-parser": "^1.20.2",
            "cors": "^2.8.5",
            "express": "^4.18.2",
            "graphql": "^16.7.1",
            "unit-http": "^1.30.0"
  4. Run the following command so Unit can access the application directory:

    # chown -R unit:unit /path/to/app/


    The unit:unit user-group pair is available only with official packages, Docker images, and some third-party repos. Otherwise, account names may differ; run the ps aux | grep unitd command to be sure.

    For further details, including permissions, see the security checklist.

  5. Next, prepare the Apollo configuration for Unit:

        "listeners": {
            "*:80": {
                "pass": "applications/apollo"
        "applications": {
            "apollo": {
                "type": "external",
                "working_directory": "/path/to/app/",
                "executable": "/usr/bin/env",
                "arguments": [
  6. Upload the updated configuration. Assuming the JSON above was added to config.json:

    # curl -X PUT --data-binary @config.json --unix-socket \
           /path/to/control.unit.sock http://localhost/config/


    The control socket path may vary; run unitd -h or see Startup and Shutdown for details.

    After a successful update, your app should be available on the listener’s IP address and port:

    Apollo on Unit