ISTIO
Checking Envoy Config
I think you can analyze the configuration by dumping the proxy config for a given sidecar. You can use istioctl proxy-config for this. You can look at the source code to see how it does this.
Troubleshooting Proxy Routes
You can dump the routes of the istio ingressgateway deployment to see how its configured
istioctl proxy-config route ${POD}.${NAMESPACE}This will show you something like the following
NAME DOMAINS MATCH VIRTUAL SERVICE
http.80 * /site site-v1.gateway
* /healthz/ready*
* /stats/prometheus* So here you can see what virtual services have created routes inside the gateway.
Try to port-forward to ingressgateway and then access reverse proxy routes through it
I think the gateway name in the virtual service needs to be in the form {gateway-namespace}/{gateway name} https://istio.io/latest/docs/reference/config/networking/virtual-service/
Make sure side car is running
Make sure hosts field in the virtual service is correct
istioctl describe
See https://istio.io/latest/docs/ops/diagnostic-tools/istioctl-describe/
N.B. I haven’t figured out why istioctl doesn’t seem to output information about virtual services when doing istioctl x describe pod ${POD}