Redirect requests to / using redirectRegex middleware?

Traefik Traefik v2
, ,
1

I'm using k3s to host a few local services, which are exposed using
IngressRoutes like this:

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: grafana
spec:
  entryPoints:
    - web
  routes:
    - match: Host(`monitoring.internal`) && PathPrefix(`/grafana`)
      kind: Rule
      services:
        - name: grafana
          port: 3000

This works just fine. The difficulty I have is that requests for
http://monitoring.internal/ result in a 404 error. I'd like to
redirect those requests to /grafana/. I tried creating a middleware
like this:

apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: redirect-to-grafana
spec:
  redirectRegex:
    regex: ^https?://monitoring.internal/?$
    replacement: http://monitoring.internal/grafana/

And an ingressroute like this:

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
  name: default
spec:
  entryPoints:
    - web
  routes:
    - match: Host(`monitoring.internal`) && PathPrefix(`/`)
      kind: Rule
      middlewares:
        - redirect-to-grafana

But this seems to result in an error; looking at the traefik logs I
see:

E0806 01:53:55.303813       1 reflector.go:138]
pkg/mod/k8s.io/client-go@v0.20.2/tools/cache/reflector.go:167: Failed
to watch *v1alpha1.IngressRoute: failed to list
*v1alpha1.IngressRoute: v1alpha1.IngressRouteList.Items:
[]v1alpha1.IngressRoute: v1alpha1.IngressRoute.Spec:
v1alpha1.IngressRouteSpec.Routes: []v1alpha1.Route:
v1alpha1.Route.Middlewares: []v1alpha1.MiddlewareRef: readObjectStart:
expect { or n, but found ", error found in #10 byte of
...|ewares":["redirect-t|..., bigger context ...|l`) \u0026\u0026
PathPrefix(`/`)","middlewares":["redirect-to-grafana"]}]}}],"kind":"IngressRouteLis|...

What's the correct way of doing this?

Thanks!