unexpected status code when backend timeout occurs

[teodorescuserban]

I am using souin cache as caddy module.

More details are here.

I am getting status code 200 with the body "Internal server error" when the backend does not respond before the timeout.backend.

I would expect at least a 504.

[darkweak]

@teodorescuserban can you try with the latest commit (as mentioned here: #585 (comment)) please? 🙏

[teodorescuserban]

I'd happily try it, but I need a correct commit sha I think.

65.45 2025/01/22 14:34:36 [INFO] exec (timeout=0s): /usr/local/go/bin/go get -v github.com/darkweak/souin@e5c1440eb3a0c1c6832488a6605e842c09ecc04a github.com/caddyserver/caddy/[email protected]
79.74 go: github.com/darkweak/souin@e5c1440eb3a0c1c6832488a6605e842c09ecc04a: invalid version: unknown revision e5c1440eb3a0c1c6832488a6605e842c09ecc04a

[teodorescuserban]

With the new commit shas provided in #585 I was able to build and test. It looks better.

I set the backend timeout for testing to 30s.

cache {
	timeout {
		backend 30s
		cache 5s
	}
}

I am getting the expected 504 status code. However, there is something amiss.

In caddy, I have configured

	handle_errors 5xx {
		respond `{"code":"{err.status_code}","message":"{err.status_text}"}`
	}

when I am forcing the reverse_proxy to expire before the cache backend timeout by setting

	reverse_proxy {
		...
		transport http {
			response_header_timeout 10s
		}
	}

I am also getting the expected {"code":"504","message":"Gateway Timeout"} with the expected headers:

...
content-type: application/json
...
cache-status: cache; fwd=uri-miss; key=/v3/viewLog?day=1; detail=SERVE-HTTP-ERROR

However, when the cache backend is hit first, I do get 504 status code, but I get a plaintext response Internal server error
with different headers:

...
content-type: text/plain; charset=utf-8
...
cache-status: hpc; fwd=bypass; detail=DEADLINE-EXCEEDED

Now, I don't mind the cache-status header differences, but I do need to provide a json response, not a plaintext response.

Any ideas, @darkweak?

cc @francislavoie - perhaps modules order? the cache module is called inside a route, but I cant add handle_response inside that route... :\

[francislavoie]

I don't know what you mean. handle_response is an option for reverse_proxy, it's not a directive of its own. You can use intercept to have a general-purpose handle_response (for non-reverse_proxy response writing).

[teodorescuserban]

I don't know what you mean. handle_response is an option for reverse_proxy, it's not a directive of its own. You can use intercept to have a general-purpose handle_response (for non-reverse_proxy response writing).

Thank you for replying, @francislavoie and sorry for the typo. I meant handle_errors, as [correctly] pasted above in the config excerpt.

[francislavoie]

Ah, yeah handle_errors is special, it's a separate route context, must go top-level and not inside other routes.