istio unable to access kubernetes dashboard - kubernetes

Question

I am trying to access the Kubernetes Dashboard through an Istio Gateway + Virtual Service.
However, all I get is 404 page not found when I try to access the dashboard with browser. Accessing the Dashboard through k8s NodePort or k8s LoadBalancer service works just as expected. The pod, however, complains in the logs about http: TLS handshake error from 127.0.0.6:52483: remote error: tls: bad certificate.
Running httpbin through Istio (as given in their documentation) works as expected, so Istio seem to be working fine as well.
I am using the official Kubernetes Dashboard YAML-s. I am giving the service below (with type: LoadBalancer added, although it doesn't seem to make a difference for Istio, although it allows me to access the Dashboard through a separate IP).
Just for the record, my k8s cluster is comprised of VirtualBox machines running MetalLB.
kubectl get services --all-namespaces returns the following:
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
default kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 11d
httpbin httpbin ClusterIP 10.100.186.188 <none> 8000/TCP 47h
istio-system istio-egressgateway ClusterIP 10.109.231.163 <none> 80/TCP,443/TCP 5d3h
istio-system istio-ingressgateway LoadBalancer 10.111.188.94 192.168.56.46 15021:31440/TCP,80:31647/TCP,443:32715/TCP 5d3h
istio-system istiod ClusterIP 10.104.236.247 <none> 15010/TCP,15012/TCP,443/TCP,15014/TCP 5d3h
kube-system kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 11d
kubernetes-dashboard dashboard-metrics-scraper ClusterIP 10.101.131.136 <none> 8000/TCP 43h
kubernetes-dashboard kubernetes-dashboard-service LoadBalancer 10.103.130.244 192.168.56.47 443:30041/TCP 43h
kubernetes-dashboard kubernetes-dashboard-service-np NodePort 10.100.49.224 <none> 8443:30002/TCP 43h
If I try to access the LoadBalancer directly via the IP from above and through browser, I get the usual Kubernetes Dashboard login page. The browser url is https://192.168.56.47.
YAML-s:
istio-gateway.yaml:
apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
name: kubernetes-dashboard-gateway
namespace: kubernetes-dashboard
spec:
selector:
istio: ingressgateway # use Istio default gateway implementation
servers:
- port:
number: 443
name: https
protocol: HTTPS
tls:
mode: PASSTHROUGH
hosts:
- "*"
istio-virtual-service.yaml:
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: kubernetes-dashboard-virtual-service
namespace: kubernetes-dashboard
spec:
hosts:
- "*"
gateways:
- kubernetes-dashboard-gateway
tls:
- match:
- sniHosts: ["*"]
route:
- destination:
host: kubernetes-dashboard-service
port:
number: 443
dashboard-service.yaml:
kind: Service
apiVersion: v1
metadata:
labels:
k8s-app: kubernetes-dashboard
name: kubernetes-dashboard-service
namespace: kubernetes-dashboard
spec:
ports:
- port: 443
targetPort: 8443
# - port: 8000
# targetPort: 9090
selector:
k8s-app: kubernetes-dashboard
type: LoadBalancer

Answer 1

User suren has mentioned:
your gateway is listening 443. not 80
Yes, this could be a problem. You are trying to reach port 80, but you are exposing only port 443. Try to change your configuration or change your port during request.
See albo documentation about Deploy and Access the Kubernetes Dashboard.

Answer 2

Hm, I got it working with the configuration as above and with explicitly specifying a host in all places where I have previously placed a "*". I had to add that host in /etc/hosts to be able to access it in browser.
It seems that this last part was key, as well as specifying the sniHost in the Virtual Service. The other problems were mostly configuration issues with the TLS. Setting it to PASSTHROUGH seems to work, because it forces Istio to sort of forward the HTTPS request to the Kubernetes Dashboard, which is responsible for decrypting etc.