Traefik middleware doesn't work

Traefik Traefik v2 (latest)
,
1

Hey everyone...

I've got some problems using Traefik 2.4 running on kubernetes (bare metal).
I want to have a service behind the path /flask but the backend service should get /.
Here's how I have done the config ( sorry for all the files but i tried a lot of things and feel like someone who really understands it will find the error prett quickly :slightly_smiling_face: )

Clusterrole + Middleware

---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: traefik-ingress-controller

rules:
  - apiGroups:
      - ""
    resources:
      - services
      - endpoints
      - secrets
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
      - networking.k8s.io
    resources:
      - ingresses
      - ingressclasses
    verbs:
      - get
      - list
      - watch
  - apiGroups:
      - extensions
    resources:
      - ingresses/status
    verbs:
      - update
      # i feel like these are the own ressources below
  - apiGroups:
      - traefik.containo.us
    resources:
      - middlewares
      - ingressroutes
      - traefikservices
      - ingressroutetcps
      - ingressrouteudps
      - tlsoptions
      - tlsstores
      - serverstransports
    verbs:
      - get
      - list
      - watch

---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: traefik-ingress-controller

roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: traefik-ingress-controller
subjects:
  - kind: ServiceAccount
    name: traefik-ingress-controller
    namespace: kube-system
---
# added later
apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
  name: middlewares.traefik.containo.us

spec:
  group: traefik.containo.us
  version: v1alpha1
  names:
    kind: Middleware
    plural: middlewares
    singular: middleware
  scope: Namespaced

Ingress + Middleware

apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: stripprefix
spec:
  replacePath:
    prefixes:
      - /blue

---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: minimal-ingress
  namespace: default
  annotations:
         #traefik.ingress.kubernetes.io/rewrite-target: /$2
         kubernetes.io/ingress.class: traefik
         traefik.ingress.kubernetes.io/router.middlewares: default-stripprefix #also tried @kubernetescrd
spec:
  rules:
  - http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: flask-docker-service
            port:
              number: 80
      - path: /blue
        pathType: Prefix
        backend:
          service:
            name: flask-docker-service
            port:
              number: 80

Daemonset + Service Account

apiVersion: v1
kind: ServiceAccount
metadata:
  name: traefik-ingress-controller
  namespace: kube-system

---
kind: DaemonSet
apiVersion: apps/v1
metadata:
  namespace: kube-system
  name: traefik
  labels:
    app: traefik

spec:
  selector:
    matchLabels:
      app: traefik
  template:
    metadata:
      labels:
        app: traefik
    spec:
      serviceAccountName: traefik-ingress-controller
      containers:
        - name: traefik
          image: traefik:v2.4
          args:
            - --api
            - --api.insecure
            - --accesslog
            - --log.level=DEBUG
            - --entrypoints.web.Address=:80
            - --entrypoints.websecure.Address=:443
            - --providers.kubernetesingress=true
          ports:
            - name: web
              containerPort: 80
              hostPort: 80
            - name: websecure
              containerPort: 443
              hostPort: 443

Service:

kind: Service
apiVersion: v1
metadata:
  name: traefik
  namespace: kube-system
  
spec:
  ports:
    - protocol: TCP
      name: web
      port: 80
    - protocol: TCP
      name: admin
      port: 8080
    - protocol: TCP
      name: websecure
      port: 443
  selector:
    app: traefik

Right now in the logs of the traffic pod it says:
level=error msg="middleware "default-stripprefix@kubernetes" does not exist" routerName=minimal-ingress-default@kubernetes entryPointName=websecure

Also tried different things e.g. default-stripprefix ... and also different cli parameters in Daemonset but can't figure it out.

Thanks in advance for your help :slightly_smiling_face: