Rewrite-target with capture group

Strip a path prefix via regex capture; path must use (/|$)(.*) for $2 to resolve

kubectl annotate ingress <name> -n <ns> nginx.ingress.kubernetes.io/rewrite-target='/$2' nginx.ingress.kubernetes.io/use-regex='true'

More ingress-nginx commands

List ingressclasses and default

kubectl get ingressclass -o custom-columns='NAME:.metadata.name,DEFAULT:.metadata.annotations.ingressclass\.kubernetes\.io/is-default-class'

Show controllers and which IngressClass is default; only one should be marked default
Dump effective nginx config

kubectl exec deploy/ingress-nginx-controller -n ingress-nginx -- nginx -T | less

Render the full live nginx.conf with all server blocks the controller actually generated
Controller status metrics

kubectl exec deploy/ingress-nginx-controller -n ingress-nginx -- curl -s localhost:10254/nginx_status

Live active connections, reading/writing/waiting counters from the stub_status endpoint
Grep upstream timeouts in logs

kubectl logs -n ingress-nginx deploy/ingress-nginx-controller --tail=2000 | grep -iE 'upstream timed out|504|499'

Hunt backend timeouts and client-aborted requests; note: 499 means client closed before upstream replied
Canary traffic split annotation

kubectl annotate ingress <name> -n <ns> nginx.ingress.kubernetes.io/canary=true nginx.ingress.kubernetes.io/canary-weight="20"

Route 20% of traffic to a canary ingress; needs a primary ingress on the same host/path