ETag header missing from response

[Chris-Peterson444]

It looks like the ETag information isn't getting returned in the response headers. I've checked a few different endpoints (anime, characters, and manga) but it hasn't shown up in any of them.

Minimum working example:

import requests
resp = requests.get('http://api.jikan.moe/v4/anime/1')
for k in resp.headers.keys():
    print(k)

Which gives:

'Server'
'Date'
'Content-Type'
'Transfer-Encoding'
'Connection'
'Access-Control-Allow-Origin'
'Access-Control-Allow-Methods'
'Cache-Control'
'X-Request-Fingerprint'
'Expires'
'Last-Modified'
'Content-Encoding'
'Vary'
'X-Cache-Status'

I would be happy to put some time in on starting a fix, but I'm a little new to the project (and PHP), so I could use some pointers on where to start looking to solve this.

[pushrbx]

I did a bit of digging:

• ETag header doesn't appear if the response is compressed. (zlib compression is enabled by default in php I think) Relevant SO link: https://stackoverflow.com/questions/34238911/how-add-etag-header-on-json-response-in-laravel-lumen
• CacheResolver class sets the ETag header.
• The CacheResolver class is disabled / not used by default, when I tried to enable it, it breaks. It can't properly deserialize the eloquent models. (commented out in app.php:89)
• It seems like the code is using the $app->routeMiddleware function incorrectly. The docs says that the key should be the route you want that middleware to be activated for. (See: https://lumen.laravel.com/docs/9.x/middleware#registering-middleware)

Also #318 introduces changes which would make the CacheResolver class cache driver agnostic.

In the light of these I would say that caching is not there yet. Also it would be nice to know @irfan-dahir which caching mechanism is which. I can see CacheResolver and Microcaching. Microcaching only works when redis is the cache driver. Why did you drop CacheResolver?

[irfan-dahir]

CacheResolver is from v3 where there's no database and everything is being cached on Redis.

Also, ETag from the code was removed because Nginx was supposed to be handling ETag. 😓

This should be resolvable from the master server directly. I'll look into it.

[irfan-dahir]

Microcaching only works when redis is the cache driver.

This should be fixed with #318 .

[irfan-dahir]

Also, ETag from the code was removed because Nginx was supposed to be handling ETag. 😓 This should be resolvable from the master server directly. I'll look into it.

Nevermind, it is not - just for static caching. Although I could've sworn it was handling it before with Nginx caching. 🤔

A fix for this would be an ETag middleware that handles comparing the Etag's (If-None-Match) hash with the controller's response hash since we are not just cashing responses now, we are querying it as well.

[pushrbx]

A fix for this would be an ETag middleware that handles comparing the Etag's (If-None-Match) hash with the controller's response hash since we are not just cashing responses now, we are querying it as well.

Watch out for this then: https://stackoverflow.com/questions/34238911/how-add-etag-header-on-json-response-in-laravel-lumen Also RoadRunner comes with an RFC7234 compliant cache driver which includes etags: https://roadrunner.dev/docs/middleware-cache/2.x/en Which also can be used to reduce caching related code in Jikan API. It also supports distributed caches if anyone would fancy running Jikan API on Kubernetes/Openshift/AWS ECS 🤣