docker CORS error

[hyh1618]

Hi Thomaxxl,

Please help. I have code working fine, but when go into a docker instance, as the hostname is not normal: it has internal hostname not available to outside, and outside hostname not reachable by running process. I can bring up the swagger page, but any action will throw "CORS, Network Failure, URL scheme must be http or https for CORS request". I think the problem is that SAFRS is getting generated swagger files as local file, not through http. Any idea on a quick fix?

I did add line of "cors = CORS(app, resource ...), not help.

[thomaxxl]

Did you specify the swagger_host argument? Like in this example:

safrs/examples/demo_pythonanywhere_com.py

Line 276 in cf75e82

host=swagger_host,

[hyh1618]

Yes, I did refer to this sample. I have used internal hostname, 127.0.0.1, etc. If you mean to use external hostname, I tried but it will fail to bind on it, as process inside docker can't see that hostname, even I can connect to this instance by that hostname.

[hyh1618]

what resources it will open as File? can we make them through http? I do have another web server in same instance.

[thomaxxl]

The SAFRSAPI swagger_host argument should be different from the host argument passed to app.run() in your case. Can you verify this please?

[hyh1618]

I did, used "0.0.0.0" and None inside SAFRSAPI(), and run with other hostname port, still same error:

CORS
Network Failure
URL scheme must be "http" or "https" for CORS request

[thomaxxl]

Some debug tips:

1. The CORS error may be misleading: if the IP is not reachable (for example when DNS doesn't resolve), the browser console also shows this error. Please verify the actual request from the network tab in the browser dev tools.

2. SAFRSAPI swagger_host should reference the external ip or DNS name, the app.run() host argument refers to the local bind IP address (typically 0.0.0.0)

3. You can check if the API endpoints are available, for example if you have a /api/users endpoint, then you should check if you get a response for http://x.x.x.x/api/users where x.x.x.x is the external IP of the container

4. You can check the swagger.yaml: paste it in https://editor.swagger.io/ , replace the IP or hostname by the external IP of the container, then check if it works (note this may lead to actual CORS errors, i.e. the Access-Control-Allow-Origin is not set or restricted)

[hyh1618]

I did use external and internal per #2. Now its not CORS error, its "internal server error". Flask abort, safrs/jsonapi_formatting.py throw GenericError(f"{exc}")

[thomaxxl]

This means there is an error in your implementation. The stacktrace in the container logs contains more information.

[hyh1618]

there is no meaningful error msg, and same code works fine in my local. The error included end point url is using the external hostname. Is it because that external is not resolvable inside docker instance?

[thomaxxl]

The error you see comes from the location where the actual sqlalchemy query is executed. Maybe there is a problem with your db connection but I can't tell without more information.
What db backend do you use?

[hyh1618]

It's sqlite. I can start the app and see the home page, just when I run any end point it throw this error. The sqlite db did created, and my other program in same docker tested sqlite OK. The problem should be with safrs/sqlalchemy/flask

[L4db]

Maybe increase the debug level in `app.config`, or by setting the `FLASK_DEBUG` env var. Thomas Pollet

…

________________________________ From: hyh1618 ***@***.***> Sent: Wednesday, November 16, 2022 7:50:35 PM To: thomaxxl/safrs ***@***.***> Cc: Subscribed ***@***.***> Subject: Re: [thomaxxl/safrs] docker CORS error (Discussion #134) It's sqlite. I can start the app and see the home page, just when I run any end point it throw this error. The sqlite db did created, and my other program in same docker tested sqlite OK. The problem should be with safrs/sqlalchemy/flask — Reply to this email directly, view it on GitHub<#134 (reply in thread)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AKVH5W6LSUNIQSPC5VJBBYTWIUUHXANCNFSM6AAAAAASCLFGEI>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[hyh1618]

I did that. not much besides: safrs.errors.GenericError, ERROR:safrs.safrs_init. ..., KeyError: <weakref at ..., to Flask ar ..

[hyh1618]

BTW, why your sample code use swagger_host="0.0.0.0"?

[thomaxxl]

Oh, you get that error. #127

Can you downgrade Flask-SQLAlchemy to v2.5.1?

[hyh1618]

Thanks, it fixed that error!

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On Wed, Nov 16, 2022 at 11:55 PM Thomas Pollet ***@***.***> wrote: Oh, you get that error. #127 <#127> Can you downgrade Flask-SQLAlchemy to v2.5.1? — Reply to this email directly, view it on GitHub <#134 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANENUR3SVUENLTCI2L5DUGDWIW3FVANCNFSM6AAAAAASCLFGEI> . You are receiving this because you authored the thread.Message ID: ***@***.***>