Plugin Compatibility Issue: Redis integration in Krakend Go Plugin for Rate Limiting Fails to Load Due to xxhash Mismatch.

[Somu-1511-gif]

Environment
KrakenD Version: 2.7.2

Go Version: 1.22.7

glibc Version: 2.31 (Debian 11)

Deployment: KrakenD and Redis are deployed on separate VMs on the same internal network (not containerized).

What We're Trying to Do
We’re compiling a Go plugin using:

github.com/redis/go-redis/v9

A global rate-limiting logic that stores counts per second in Redis

Loaded via krakend.json under the plugin.handler section

The Problem
When restarting KrakenD after compiling the plugin as a .so file, we get the following log output:
KRAKEND DEBUG: [SERVICE: Plugin Loader] Starting loading process
KRAKEND DEBUG: [SERVICE: Executor Plugin] plugin #0 (plugins/ratelimiterplugin.so): plugin.Open("plugins/ratelimiterplugin"): plugin was built with a different version of package github.com/cespare/xxhash/v2
KRAKEND DEBUG: [SERVICE: Handler Plugin] plugin #0 (plugins/ratelimiterplugin.so): plugin.Open("plugins/ratelimiterplugin.so"): plugin was built with a different version of package github.com/cespare/xxhash/v2 (previous failure)
KRAKEND DEBUG: [SERVICE: Modifier Plugin] plugin #0 (plugins/ratelimiterplugin.so): plugin.Open("plugins/ratelimiterplugin.so"): plugin was built with a different version of package github.com/cespare/xxhash/v2 (previous failure)

I understand that Go plugins must be built with identical dependency versions but ensuring this is difficult when working outside KrakenD’s vendor tree. Even explicitly setting the xxhash/v2 version to match doesn’t resolve the issue due to internal linking behavior.

I’d appreciate:

Clear guidance on the recommended way to build plugins compatible with KrakenD CE, especially when external packages like Redis are involved.

Whether Redis integration in plugins is officially supported or discouraged.

Optionally, an official Redis rate-limiting plugin or template to extend cleanly.

[taik0]

Hi @Somu-1511-gif ,

Can you try using the check-plugin command? The -f flag will output the required go get commands to fix the dependency issue.

[Somu-1511-gif]

Hi @taik0 ,
krakend check-plugin -f path/to/your/plugin.so

output-:
libc
have:
want: GLIBC-2.31_(debian-11)
go mod edit --replace github.com/cespare/xxhash/v2=github.com/cespare/xxhash/v2@v2.3.0
2 incompatibilities found

[alombarte]

Regarding:

Whether Redis integration in plugins is officially supported or discouraged.

Redis is supported on KrakenD Enterprise: https://www.krakend.io/docs/enterprise/service-settings/redis-connection-pools/ so it is officially supported but this part is not open sourced.

[Somu-1511-gif]

Hi @alombarte, if I implement custom Redis integration in a KrakenD plugin (e.g., using go-redis), will that work reliably with the open-source version, or is that discouraged?

Is Redis only available for internal use by KrakenD Enterprise features (e.g., caching, connection pools)?

Can I safely use Redis in a plugin with the open-source KrakenD via Go?

[alombarte]

The open-source version does not limit the integrations you want to do on plugins in any way. So you can use Redis or any other technology you please to integrate with KrakenD, and it will work as reliably as you code it.

I just wrote an example of a reliable usage of Redis within KrakenD, which is the Enterprise edition, so you would be able to code a similar piece for yourself. Enterprise uses the open-source version as the base.

[Somu-1511-gif]

I ran krakend check-plugin on my ratelimiter.so plugin and got the following output:

libc
have:
want: MUSL-1.2.5_(alpine-3.21.3)
1 incompatibilities found

Does this incompatibility prevent my plugin from being loaded by KrakenD?

[taik0]

No, it only means that you must use an Alpine (the default builder) to build the plugin.