[Traefik plugin] Read default sablierUrl from environment variable

[lgatellier]

Context

Sablier version : 1.9.0
Provider : Kubernetes
Proxy : Traefik

For now, Sablier URL must be set in all Middleware CRs.

Feature proposal

Make Sablier Traefik plugin read a SABLIER_URL environment variable as the default URL for the Sablier endpoint, to avoid repeating the URL in all middlewares.

By the way, thanks, and congratulations for this really simple and powerful project ! 👏

[acouvreur]

Can we read environment variable from middlewares with the Traefik plugin system?

[lgatellier]

Hi @acouvreur,

Sorry for the delay.
I have no idea if Traefik plugin system allows to read environment variables, but I think it may be possible, since it's just some Go code running in the same environment.

[thomas-mc-work]

What about putting it into the config?

https://sablierapp.dev/#/configuration?id=configuration-file

The other sibling parameters can already be defined there. The new one could just be named default-sablier-url.

[acouvreur]

That's the configuration for the Sablier API, the traefik plugin itself cannot use this configuration file.

What we need is the ability to setup a default value for multiple plugins, or change the current plugin to be reusable by different routes.

For the first option, a feature request must be opened to the traefik repository.

For the second option, the plugin must be restructured to support that, but I don't think this is possible without calling the Traefik API when receiving a request to know what router is being matched.

We could also open an issue to traefik so that the matched router is available in the middleware.

[thomas-mc-work]

…, or change the current plugin to be reusable by different routes.

That sounds better for me from an architectural perspective. I think there shoukd be only one or maximal two plugin definitions (dynamic and blocking).

For the first option, a feature request must be opened to the traefik repository.

I think this would be overkill and also possibly a lengthy process.