How to debug plugin errors

Traefik Pilot
#1

hi

we made a plugin (duplicateheader) and it works, but sometimes I get an error:

plugins-storage/sources/gop-721926268/src/github.com/containeroo/duplicateheader/duplicateheader.go:34:6: panic

any idea how I can get a better error message?

best,
giotto

#2

Hello,

could you provide a small reproducible example?

It's probability an issue with Yaegi.

#3

Hi Idez

I create this middleware:

middlewares:
  cf-real-ip:
    plugin:
      duplicateheader:
        source: Cf-Connecting-Ip
        destination:
          - X-Real-Ip
          - X-Forwarded-For

I add the middleware to the websecure entrypoint:

- --entrypoints.websecure.http.middlewares=cf-real-ip@file

The Plugin works, it can copy the Header Cf-Connecting-Ip to the Headers X-Real-Ip and X-Forwarded-For. I checked this in some access-logs.

The error happens randomly and not so oftem.

fyi:

We try to update the headers with req.Header.Set, the error came anyway. The we try to update the headers with req.Header.Del and req.Header.Add, but the error also appears.