portainer on K3s with traefik ingress

CreatePortainerOnK3s.sh

kubectl create -f - <<EOF
---
kind: Namespace
apiVersion: v1
metadata:
  name: portainer
  labels:
    name: portainer
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: portainer
  namespace: portainer
  labels:
    app: portainer
spec:
  replicas: 1
  selector:
    matchLabels:
      app: portainer
  template:
    metadata:
      labels:
        app: portainer
    spec:
      serviceAccountName: portainer-sa-clusteradmin
      containers:
        - name: portainer
          image: portainer/portainer-ce:latest
          imagePullPolicy: Always
          ports:
            - containerPort: 9000
---
kind: Service
apiVersion: v1
metadata:
  name: portainer-service
  namespace: portainer
spec:
  ports:
    - name: portainer-service-port
      port: 9000
      protocol: TCP
      targetPort: 9000
  selector:
    app: portainer
---
# Middleware
# Strip prefix /portainer
apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: portainer-admin
  namespace: portainer
spec:
  stripPrefix:
    forceSlash: false
    prefixes:
      - /portainer
---
kind: Ingress
apiVersion: networking.k8s.io/v1
metadata:
  name: portainer-ingress
  namespace: portainer
  annotations:
    kubernetes.io/ingress.class: traefik
    traefik.ingress.kubernetes.io/router.middlewares: portainer-portainer-admin@kubernetescrd
spec:
  ingressClassName: traefik #can be left blank if a default exists
  rules:
    - host: 
      http:
        paths:
        - path: /portainer
          pathType: Prefix
          backend:
             service:
               name: portainer-service
               port:
                 number: 9000
---
# Source: portainer/templates/rbac.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: portainer
  labels:
    app.kubernetes.io/name: portainer
    app.kubernetes.io/instance: portainer
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
  - kind: ServiceAccount
    namespace: portainer
    name: portainer-sa-clusteradmin
---
# Source: portainer/templates/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: portainer-sa-clusteradmin
  namespace: portainer
  labels:
    app.kubernetes.io/name: portainer
    app.kubernetes.io/instance: portainer
EOF