#!/usr/bin/env bash
# T31: envoy_http_downstream_rq_active is NOT exposed on /stats/prometheus by default;
#      it appears only after proxyStatsMatcher.inclusionRegexps is added via the
#      proxy.istio.io/config pod annotation (which requires pod recreation to take effect).
set -euo pipefail

NS="istio-vt-t31"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
MANIFEST="${SCRIPT_DIR}/manifest.yaml"

cleanup() {
  kubectl delete namespace "$NS" --wait=false --ignore-not-found
}
trap cleanup EXIT

kubectl create namespace "$NS"
kubectl label namespace "$NS" istio-injection=enabled

kubectl apply -f "$MANIFEST"
kubectl -n "$NS" wait --for=condition=Ready pod/client --timeout=90s
kubectl -n "$NS" rollout status deploy/echo --timeout=120s

echo ">>> BEFORE annotation: expect 0"
kubectl -n "$NS" exec client -c istio-proxy -- curl -s localhost:15000/stats/prometheus \
  | grep -c 'envoy_http_downstream_rq_active' || true

kubectl -n "$NS" annotate pod client \
  'proxy.istio.io/config={"proxyStatsMatcher":{"inclusionRegexps":[".*downstream_rq_active.*"]}}' \
  --overwrite

# Annotating a live bare Pod does NOT reconfigure the already-injected sidecar;
# the pod must be deleted/recreated so the injection webhook re-reads the annotation.
# manifest.yaml already has the annotation baked into the client Pod spec.
kubectl -n "$NS" delete pod client --wait=true
kubectl apply -f "$MANIFEST"
kubectl -n "$NS" wait --for=condition=Ready pod/client --timeout=90s

echo ">>> AFTER annotation + pod recreation: expect >0"
kubectl -n "$NS" exec client -c istio-proxy -- curl -s localhost:15000/stats/prometheus \
  | grep -c 'envoy_http_downstream_rq_active' || true