Can't get cache-handler to work

What happened?

I want to do some HTTP caching to make API faster. My final point is to use 103 Early Hints + HTTP cache on reverse proxy side with invalidation via Souin API.

According to the docs, i need to rebiuld FrankenPHP Docker image to include cache-handler module there, and one of available storage drivers. Then I need to do some configuration in Caddy and api_platform and then it should work.

What i've made:

Changed Dockerfile. Created additional stage, where Caddy built with xcaddy, and then copied into another stage:

ARG PHP_VERSION=8.3

FROM dunglas/frankenphp:latest-builder-php$PHP_VERSION AS builder
COPY --from=caddy:builder /usr/bin/xcaddy /usr/bin/xcaddy
RUN --mount=target=/var/lib/apt/lists,type=cache,sharing=locked \
    --mount=target=/var/cache/apt,type=cache,sharing=locked \
        apt-get update && apt-get install --no-install-recommends -y \
        git

ENV CGO_ENABLED=1 XCADDY_SETCAP=1 XCADDY_GO_BUILD_FLAGS="-ldflags \"-w -s -extldflags '-Wl,-z,stack-size=0x80000'\""
RUN xcaddy build \
    --output /usr/local/bin/frankenphp \
    --with github.com/dunglas/frankenphp=./ \
    --with github.com/dunglas/frankenphp/caddy=./caddy/ \
    --with github.com/dunglas/mercure/caddy \
    --with github.com/dunglas/vulcain/caddy \
    --with github.com/dunglas/caddy-cbrotli \
    --with github.com/darkweak/souin/plugins/caddy@65cb24114d76a7de3f4e8c7b8ef7df3efd028899 \
    --with github.com/darkweak/souin@65cb24114d76a7de3f4e8c7b8ef7df3efd028899 \
        --with github.com/darkweak/storages/otter/caddy

FROM dunglas/frankenphp:1-php$PHP_VERSION AS upstream
COPY --from=builder --link /usr/local/bin/frankenphp /usr/local/bin/frankenphp

# .... 
# Dockerfile continues

One difference from the docs is additional Otter storage module.

Caddyfile updated. Added global option cache with some config and cache option in my application config. My full featured, minimal config here:

{

    cache {
        otter
        api {
            souin
        }
        log_level debug
    }

    order vulcain after reverse_proxy
    order php_server before file_server
}

# API Platform application
api.{$DOMAIN}, http://localhost {

    cache
    vulcain

    header ?Permissions-Policy "browsing-topics=()"

    php_server
}

# Frontend web application on React behind proxy
{$DOMAIN} {
    reverse_proxy http://web:3000
}

The only one thing here, not highlighted in docs - is otter storage configured. I believe, that it's zero-config in-memory storage, which just should work.

API Platform config updated. Added configuration for cache purger:

api_platform:
http_cache:
invalidation:
  urls: [ 'http://localhost/souin-api/souin' ]
  purger: api_platform.http_cache.purger.souin

Added cache headers for one of my ApiResource's operation:

#[ORM\Entity(repositoryClass: IconRepository::class)]
#[ApiResource(
    operations: [
        new Get(
            cacheHeaders: [
                'public' => true,
                'max_age' => 30,
                'shared_max_age' => 60,
                'stale_while_revalidate' => 100,
                'vary' => ['Content-Type', 'Accept', 'Origin']
            ],
        ),
        new GetCollection(),
        new Post(),
        new Patch(
            denormalizationContext: ['groups' => ['Icon:update']]
        ),
    ]
)]
class Icon
{
// ...
}

After that, http caching started to work. Cache headers are present in responses from reverse proxy and seems to be ok. On the first hit by operation it shows cache miss, and declares cache lifetime, status 200 Ok

On the second hit it shows cache ttl, cache storage, etc. Statud 304 Not Modified.

Quite ok .... but ... there are some symptoms showing it not work properly:

I can't see s-maxage in response (I don't really know, maybe i shouldn't). My Vary headers in config differs from Vary headers in response.
In Caddy (FrankenPHP) logs i can see some strange stuff:

On the first hit by operation after Caddy startup i see error, that key cannot be found in Otter:

api-1            | 2024/10/04 12:24:12.128  ERROR   storages.cache.otter    Impossible to get the mapping key IDX_GET-https-api.****.***-/icons/1 in Otter
api-1            | 2024/10/04 12:24:13.920  ERROR   storages.cache.otter    Impossible to get the key SURROGATE_https://api.****.***/icons/1 in Otter
api-1            | 2024/10/04 12:24:13.920  ERROR   storages.cache.otter    Impossible to get the key SURROGATE_/icons/1 in Otter

On every 304 response logs not producing any output.

On every cache miss (200 Ok) i can see the following error from FrankenPHP:

api-1            | 2024/10/04 12:25:04.863  ERROR   the current responseWriter is not a flusher {"error": "feature not supported"}

According to Souin documentation, there is a way to check all cached keys via API. It metioned here

I'm expecting, that when i calling GET http://localhost/souin-api/souin or GET http://localhost/souin-api/souin/surrogate_keys, it will respond me the list of stored cache keys. Calling this request with curl from inside a container returns empty list with 200 Ok:

root@40efb759dfd5:/app# curl -v http://localhost/souin-api/souin
*   Trying 127.0.0.1:80...
* Connected to localhost (127.0.0.1) port 80 (#0)
> GET /souin-api/souin HTTP/1.1
> Host: localhost
> User-Agent: curl/7.88.1
> Accept: */*
>
< HTTP/1.1 200 OK
< Content-Type: application/json
< Permissions-Policy: browsing-topics=()
< Server: Caddy
< Date: Fri, 04 Oct 2024 11:55:10 GMT
< Content-Length: 2
<
* Connection #0 to host localhost left intact
[]

The most important part for me - Invalidation API seems not working. I modify an icon ApiResource with PATCH query, or create the new one. ApiPlatform really call the souin api PURGE http://localhost/souin-api/souin, but it has no effect, as i see. Cache isn't invalidated, and reverse proxy continues to respond with 304 Not Modified after invalidation request from purger.

I tried to call curl requests to PURGE by myself:

root@40efb759dfd5:/app# curl -v -X PURGE http://localhost/souin-api/souin/IDX_GET-https-api.****.***-/icons/1
*   Trying 127.0.0.1:80...
* Connected to localhost (127.0.0.1) port 80 (#0)
> PURGE /souin-api/souin/IDX_GET-https-api.****.***-/icons/1 HTTP/1.1
> Host: localhost
> User-Agent: curl/7.88.1
> Accept: */*
>
< HTTP/1.1 204 No Content
< Permissions-Policy: browsing-topics=()
< Server: Caddy
< Date: Fri, 04 Oct 2024 12:29:50 GMT
<
* Connection #0 to host localhost left intact

Same result with all my surrogate keys for that operation.

Also i tried to change cache storage to badger instead of otter:

{
    cache {
        badger {
            path /data/badger
        }
        api {
            souin
        }
        log_level debug
    }
}

It behaves similarly except it not spam in logs with message "Impossible to get the mapping key", like Otter. Badger storage creates configured folder inside docker container, there are some database file in there.

Souin API GET http://localhost/souin-api/souin gets some data from it:

root@4c566d2e930b:/app# curl -v -X GET http://localhost/souin-api/souin Note: Unnecessary use of -X or --request, GET is already inferred.

Trying 127.0.0.1:80...
Connected to localhost (127.0.0.1) port 80 (#0)

GET /souin-api/souin HTTP/1.1 Host: localhost User-Agent: curl/7.88.1 Accept: /

< HTTP/1.1 200 OK < Content-Type: application/json < Permissions-Policy: browsing-topics=() < Server: Caddy < Date: Fri, 04 Oct 2024 12:44:06 GMT < Content-Length: 279 <
Connection #0 to host localhost left intact ["GET-https-api.*.-/icons/1{-VARY-}Accept:text%2Fhtml%2Capplication%2Fxhtml%2Bxml%2Capplication%2Fxml%3Bq%3D0.9%2Cimage%2Favif%2Cimage%2Fwebp%2Cimage%2Fapng%2C%2A%2F%2A%3Bq%3D0.8%2Capplication%2Fsigned-exchange%3Bv%3Db3%3Bq%3D0.7;Content-Type:;Authorization:;Origin:"]

BTW. If i call PURGE after that and GET /souin-api/souin again, the key is still exists. Maybe i use PURGE request not very properly.

And again, i see FrenkenPHP errors on every cache miss response

api-1            | 2024/10/04 12:44:04.798  ERROR   the current responseWriter is not a flusher {"error": "feature not supported"}

So, I see one error, which i can't understood, and possibly it's a signal to non working cache-handler inside FrankenPHP environment. I try to figure out, where the problem is - inside FrankenPHP, or inside Souin. And the main question, what should i do to fix that behavior.

And probably another one problem with Otter, which is relevant, but not bother me.

Thank you!

Build Type

Docker (Debian Bookworm)

Worker Mode

Operating System

macOS

CPU Architecture

Apple Silicon

PHP configuration

Relevant log output

api-1            | 2024/10/04 12:44:04.798  ERROR   the current responseWriter is not a flusher {"error": "feature not supported"}

dunglas / frankenphp