Apollo Server v4 Integration into Firebase Cloud Functions

[TangrisJones]

Hey all 👋 , just wanted to mention this solution I seem to have found on deploying an apollo server v4 on a firebase cloud function.

Seems to work for me so far but it dosent seem to be documented anywhere....? I've found related work here, but this solution seems to be an alternative to that.

The TLDR; we deploy an express server on a firebase onRequest function.

Heres the code:

import * as functions from "firebase-functions";
import cors from "cors";
import express from "express";
import { expressMiddleware } from "@apollo/server/express4";
import { ApolloServer } from "@apollo/server";
import { schema } from "./schemas";
import http from "http";
import { ApolloServerPluginDrainHttpServer as apolloServerPluginDrainHttpServer } from "@apollo/server/plugin/drainHttpServer";

export interface Context {
  someField: string | null;
}

// Required logic for integrating with Express
export const app = express();
const httpServer = http.createServer(app);

export const server = new ApolloServer<Context>({
  schema,
  csrfPrevention: true,
  introspection: process.env.NODE_ENV === "development",
  plugins: [apolloServerPluginDrainHttpServer({ httpServer })],
});

server
  .start()
  .then(() =>
    // Set up our Express middleware to handle CORS, body parsing,
    // and our expressMiddleware function.
    app.use(
      "/",
      cors<cors.CorsRequest>(),
      express.json(),
      // expressMiddleware accepts the same arguments:
      // an Apollo Server instance and optional configuration options
      expressMiddleware(server, {
        context: async ({ req }) => ({ someField: "123" }),
      })
    )
  )
  .catch((err) => {
    throw err;
  });

export const api = functions.https.onRequest(app);

Seems to work well for me in initial testing! Let me know if anyone has thoughts / opinions on it... I'm a little nervous about this solution because of the lack of documentation... Hope it helps someone though 😄

[trevor-scheer]

One caveat here is you're not awaiting server.start(), so it's possible that Apollo Server isn't ready to serve requests before it starts actually getting them. And in this configuration, you won't even have a / route established yet if the start() promise hasn't resolved.

[MichelFloyd]

Here's a working repo