Cross Origin Requests about crystal

[estaub]

For anyone else who struggles to understand... the CORS headers are now disabled by default, and enabled on the command line by --cors.

[benjie]

https://github.com/postgraphql/postgraphql/blob/master/docs/cli.md

postgraphql --cors -c postgres://...

[jptissot]

I am trying to use graphql playground with postgraphile. Both are running on different origins (I am running postgraphile docker container on port 5000 and graphql-playground + my custom graphql api (using graphql-yoga) on port 4000.

The error I am having is that the playground sends OPTIONS requests to postgraphile, which seems to fail as the CORS rule is set to only allow HEAD, GET and POST.

Let me know if you need me to create a seperate issue.

[pvdvreede]

I think it would be a useful feature to have cross origin support built in so that you dont also need to have a proxy for it. Rather than being enabled by default perhaps it would be better to have an option/cli flag to enable it so that people aren't exposing that without knowing it?

[d-winter]

Any plan when this will be merged and released?

[calebmer]

@d-winter I was waiting for a LGTM, I’ll merge 😉

[calebmer]

Released in 1.8.0 👍

[d-winter]

@calebmer awesome timing 👍
Thanks a lot!

[ruslantalpa]

Just looked into this for my needs so sharing the results ...

While this feature seems like a good idea at first (no proxy needed), you will add a network overhead on each request.
The first overhead is that you will need those headers on each request (not so bad).
The second overhead is that you will have preflight request for EVERY request.
Caching preflight requests does not really work http://stackoverflow.com/questions/12013216/how-to-apply-cors-preflight-cache-to-an-entire-domain

Do a bit more work and add the proxy (a real one like nginx, not a nodejs script) and you will make your app faster.

[calebmer]

@ruslantalpa does this change with HTTP2 and/or hosting on the same domain?

Unless preflight requests seriously slow down request performance, I’m comfortable with leaving CORS on by default to simplify the beginner experience. But that’s a good optimization to be aware of, thanks so much 👍

[ruslantalpa]

I don't know about the http2
Same domain means no need for CORS ... so no preflight (OPTIONS) requests, which means the headers are not needed at all and they just add (unused) bytes to traffic.
About slowdown .. yes they do, it's all nice when it's on localhost and the OPTIONS takes 5-10ms, but move this to production over https and suddenly a requests that would take 100ms in normal conditions, turns into 2 sequential requests, each taking 100ms so in total 200ms. Mix in Relay with it's preference for splitting requests into multiple requests to node endpoint and suddenly you have a flood.

[DevPrasan1]

Hi @estaub can you please tell me the command, for how to enable cors

[pencilcheck]

Since I use expressjs as my custom server, so I just add npm install cors --save as a middleware to expressjs and done.

Yup it is for more control such as whitelist domains.

[benjie]

You can just use "enableCors" from the library settings (it's what "--cors" maps to) but using the cors middleware will give you more control 👍

[celvin]

I'm trying to use it in Docker, and behind traefik in order to setup a domain name and manage ssl, but it can only be accessed though its IP, I'm using --cors and -n 0.0.0.0 and I can't access it though a reverse proxy :(

[benjie]

Could you post more details? What command are you running, what’s the error you’re getting, how is your reverse proxy configured, etc etc?

[celvin]

Thanks a lot for your time, I have uploaded the testing environment to github, if you can check it out, I would be really grateful.

https://github.com/celvin/postgraphile-docker

I'm using traefik as a reverse proxy in order to use domain names to access different containers mapping their ports

Basically you just need to run docker-compose up --build and then you can navigate to the traefik dashboard to see the deployment details:

http://localdev.zlivio.com

and the postgraphile service (it's already routed to /graphiql) is using:

http://pgpgraph-local.zlivio.com/

and to enter to the graphile container:

docker exec -it postgraphile-nexxtel bash

[benjie]

I can't spin your env up right now, but what's the exact error you're getting?

[celvin]

There is no error in the log, and when I navigate directly to the container's IP, it works

but when I try to get it through a domain name managed by traefik (reverse proxy) it fails under timeout message.

If I post another node app in the same container it works well, so I think must be something related with allowing Cross Origin Requests or not

[benjie]

So a timeout implies it's not a CORS issue (those errors are explicit and typically immediate); sounds like it's a connectivity issue in your setup.

[celvin]

Mmm everything is possible, the thing is the same settings even the same container running another app works well through traefik but postgraphile doesn't...

[benjie]

I'm not familiar enough with Docker to be able to advise you there, sorry. Are you correctly exposing the port?

[celvin]

Thanks a lot for your support,

Yep I'm doing it well, I have had a similar issue with timeout trouble as well but with an angular 6 app, and I managed it adding --disable-host-check and listening 0.0.0.0 that's why I thought maybe the --cors option wasn't working well in postgraphil

For now I'll use it through IP but without ssl

Thanks for your time, this is a great project.

[benjie]

Are you using -n 0.0.0.0? We have this by default in our Dockerfile which you can install from graphile/postgraphile on Docker Hub.

[celvin]

Yep I have checked all the doc and that Docker file as well.

I have tried this:

1. With connection plugin:
   postgraphile -n 0.0.0.0 --cors -c postgres://$POSTGRES_USER:$POSTGRES_PASSWORD@$PGHOST:$DB_PORT/$POSTGRES_DB -a -j -M --append-plugins /plugins/connection-filter/index.js

2. without
   postgraphile -n 0.0.0.0 --cors -c postgres://$POSTGRES_USER:$POSTGRES_PASSWORD@$PGHOST:$DB_PORT/$POSTGRES_DB

It works if I navigate using the containers IP directly but not through the reverse proxy

[benjie]

Sorry, can't really help you - if it's a timeout then it's most likely a connectivity issue - the packets are literally not getting through (or getting back) - hence the timeout. Unless you think the server is hanging for some reason, but I've not known PostGraphile to hang except if you feed it a ridiculously complex GraphQL query 😈

[celvin]

haha just to get the UI so nop, hehe

thanks a lot I'll try to get all debug that I can I will read carefully everything, thanks again.

[celvin]

I've found the trouble, the domain name wasn't working properly, my mistake, thanks it is working just perfect, I will keep alive that docker-compose wrapper for postgraphile, in case somebody wants to use it

[benjie]

👍 Thanks for reporting back

[avkonst]

Has the issue been created for the last comment: #84 (comment)

I have got the same problem.

[benjie]

I don’t think so; please open one 👍

[benjie]

So the bug is actually that we're sending Access-Control-Request-Method rather than Access-Control-Allow-Methods; not sure how this has never been spotted before! Raising a PR now.

[benjie]

#838

[benjie]

So the issue actually seems to be that they're setting an X-Apollo-Tracing header. I'm going to add that to the PR too, seems harmless.