Trouble setting up a GraphQL proxy

[jonaird]

Hi,

I'm having trouble setting up a proxy server for the GraphQL endpoint. I'm using Nodejs and Express and when I try I get "Unknown path" as a response. It doesn't seem to be coming from the express server as far as I can tell. Could this be coming from the EdgeDB instance?

[jaclarke]

EdgeDB does return a 404 response with the message 'Unknown path' for http requests with a path it doesn't know.

You may not have the graphql extension enabled for your db. If you run describe schema as sdl; in the CLI, the response should contain this line: using extension graphql version '1.0'. If not, you need to add using extension graphql; to your schema file and run the migration workflow (if you prefer using ddl, then running create extension graphql; in the CLI also works).

Then you can try http://localhost:<instance-port>/db/<database-name>/graphql/explore in the browser to test it out. (database-name by default is 'edgedb', and instance-port can be found by running edgedb instance list).

[jaclarke]

Do you have a simple repo that reproduces the issue you can share?

[jonaird]

It's only a few lines so I'll just paste it here:

const express = require('express');
const { createProxyMiddleware } = require('http-proxy-middleware');
const app = express();

const portNumber = 'edgedb port number';
const endpoint  = 'http://127.0.0.1:'+portNumber+'/db/edgedb/graphql';
app.use('/graphql',createProxyMiddleware({target:endpoint,changeOrigin:true}));
app.listen(3000);

[jonaird]

I changed the proxy endpoint to '/' rather Thant '/graphql' and it seems to have fixed the issue.

[jonaird]

To be clear, it's still an issue if you want to serve from any other endpoint but serving from '/' works for now. Here's the repo if needed:
https://github.com/jonaird/edgedb-proxy-bug

[jaclarke]

As far as I understand from the http-proxy-middleware docs, this is the expected behaviour. By default the prependPath option is true, so setting the proxy path to /graphql means the request is proxied to /db/edgedb/graphql/graphql which is an invalid endpoint. To have a proxy path other than /, I think you would need to use the pathRewrite option:

const endpoint = "http://127.0.0.1:" + portNumber + "/db/edgedb/graphql";
app.use(
  "/some/custom/endpoint",
  createProxyMiddleware({
    target: endpoint,
    pathRewrite: { "^/some/custom/endpoint": "" },
  })
);