I'm trying to add middleware that adds a header and comes before ForwardAuth middleware. Using a simplified example in Docker Compose, here is what I have so far:
services:
traefik:
image: traefik:latest
ports:
- "80:80"
- "8080:8080"
command:
- --api.insecure=true
- --providers.docker
- --entrypoints.web.address=:80
- --experimental.localplugins.my-plugin.modulename=github.com/khpeek/my-plugin
volumes:
- /var/run/docker.sock:/var/run/docker.sock
- ./my-plugin:/plugins-local/src/github.com/khpeek/my-plugin
whoami:
image: traefik/whoami:latest
labels:
- traefik.enable=true
- traefik.http.routers.whoami.rule=Host(`whoami.localhost`)
- traefik.http.routers.whoami.entrypoints=web
- traefik.http.middlewares.whoami-auth.forwardauth.address=http://host.docker.internal:4181
- traefik.http.routers.whoami.middlewares=my-plugin,whoami-auth
where my directory structure is
.
├── docker-compose.yml
└── my-plugin
├── .traefik.yml
├── go.mod
└── myplugin.go
and myplugin.go reads
package myplugin
import (
"context"
"log"
"net/http"
)
type Config struct{}
func CreateConfig() *Config {
return &Config{}
}
type MyPlugin struct {
next http.Handler
name string
}
func New(_ context.Context, next http.Handler, _ *Config, name string) (http.Handler, error) {
return &MyPlugin{
next: next,
name: name,
}, nil
}
func (m *MyPlugin) ServeHTTP(w http.ResponseWriter, r *http.Request) {
log.Println("MyPlugin serving an HTTP request")
r.Header.Add("foo", "bar")
m.next.ServeHTTP(w, r)
}
with a go.mod file,
module github.com/khpeek/my-plugin
go 1.23.0
and .traefik.yml,
# The name of your plugin as displayed in the Plugins Catalog web UI.
displayName: My Plugin
type: provider
# The import path of your plugin.
import: github.com/khpeek/my-plugin
# A brief description of what your plugin is doing.
summary: Adds a header
# Medias associated to the plugin (optional)
iconPath: foo/icon.png
bannerPath: foo/banner.png
# Configuration data for your plugin.
# This is mandatory,
# and Plugins Catalog will try to execute the plugin with the data you provide as part of its startup validity tests.
testData:
Headers:
Foo: Bar
The problem is that when I run it using docker compose up, I get
[+] Running 2/0
✔ Container traefik-docker-compose-example-traefik-1 Created 0.0s
✔ Container traefik-docker-compose-example-whoami-1 Created 0.0s
Attaching to traefik-1, whoami-1
whoami-1 | 2024/09/05 15:31:53 Starting up on port 80
traefik-1 | 2024-09-05T15:31:53Z ERR error="middleware \"my-plugin@docker\" does not exist" entryPointName=web routerName=whoami@docker
It seems from similar topics that I have to add to the labels of whoami something like
- traefik.http.middlewares.my-plugin. ...
but since my-plugin doesn't have any configuration options (unlike ForwardAuth), I'm not sure what to add there. Any idea how to get this to work?
