sendIntrospectionQuery gives ECONNREFUSED with localhost server

[NicholasLYang]

This is a bit of a puzzler (and quite possibly not the fault of this library at all). I'm running my Rust/Juniper GraphQL server on localhost (port 4000) and attempting to run sendIntrospectionQuery.

A quick aside, the docs aren't really friendly to people who are using npm. Any idea what the equivalent npm command is? I'd be happy to open a PR to add it to the documentation. I'm running node node_modules/graphql_ppx/sendIntrospectionQuery if it matters.

Anyways, the script fails with an ECONNREFUSED and my server doesn't even appear to notice the request. However, when I proxy the server using ngrok, this request goes through. Any idea why this happens?

Thanks,
Nicholas

[Gregoirevda]

From npm@5.2, you can use npx
npx send-introspection-query http://my-api.example.com/api
otherwise, you need to expand your scripts in package.json

 scripts : {
     send-introspection-query: send-introspection-query http://my-api.example.com/api
 }

Can you provide details of the ECONNREFUSED?
Do you have cors enabled on your GraphQL server?

[NicholasLYang]

Ah, okay. I get the following error, which doesn't appear to be that useful:

Could not send introspection query:  { Error: connect ECONNREFUSED 127.0.0.1:4000
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1113:14)
  errno: 'ECONNREFUSED',
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '127.0.0.1',
  port: 4000 }

I do have CORS enabled on my server. Quite honestly I'm leaning towards something weird on my end, because I read the sendIntrospectionQuery code and it looks pretty straightforward.

[Gregoirevda]

Can you call it from a client supporting GraphQL like Insomnia?
Strange it only works from ngrock, sure it running in the correct place? lsof -i tcp:4000

[NicholasLYang]

Yeah, the server is running in the right place. I even did a kill -9 and restarted it to make sure it wasn't a hidden process that I didn't kill properly. My GraphiQL client works properly too. And actually, my front end app also works too now that I set up the schema via ngrok.

[idkjs]

@NicholasLYang you ever figure this out?

I just switch and endpoint from https://eu1.prisma.sh/prisma-783922/graphql-crud/dev" which works to localhost:4000 and get:

Could not send introspection query:  { Error: connect ECONNREFUSED 127.0.0.1:80
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1088:14)
  errno: 'ECONNREFUSED',
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '127.0.0.1',
  port: 80 }

Any idea what is cause of this?

I tried with ngrok and got same result:

ngrok by @inconshreveable                                                            (Ctrl+C to quit)

Session Status                online
Account                       Enso (Plan: Free)
Version                       2.3.28
Region                        United States (us)
Web Interface                 http://127.0.0.1:4040
Forwarding                    http://fce66f54.ngrok.io -> http://localhost:4000
Forwarding                    https://fce66f54.ngrok.io -> http://localhost:4000

Connections                   ttl     opn     rt1     rt5     p50     p90
                              0       0       0.00    0.00    0.00    0.00

If run npx fetch-graphql-schema http://localhost:4000 it works. Can I use that in place of yarn send-introspection-query?

[idkjs]

Disregard my comments. Typo in url. Had http://localhost/4000 instead of http://localhost:4000

[Ejhfast]

@NicholasLYang this issue also drove me a bit crazy today. It seems that Rocket has some issues serving on localhost: https://stackoverflow.com/a/59668606

For me the following worked:
npx get-graphql-schema http://[::1]:4000/graphql -j

Whereas the query I would typically do does not work:
npx get-graphql-schema http://localhost:4000/graphql -j

This was really surprising and hard to debug. I imagine many people are combining a Rust/Rocket/Juniper backend and Reason/Apollo frontend, so perhaps it is worth calling out this issue somewhere in the documentation.

So that search engines can further index on the error state, the error I was initially getting was:
FetchError: request to http://localhost:4000/ failed, reason: connect ECONNREFUSED 127.0.0.1:4000

[renehauck]

For my future self and also all other help seekers: If you use the local route ip via ifconfig instead of localhost, it worked for me.