#!/usr/bin/env bash
# T30: terminationDrainDuration / istio-agent SIGTERM drain behavior verification
set -euo pipefail

NS=istio-vt-t30
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

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

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

echo "=== apply manifest ==="
kubectl apply -f "$SCRIPT_DIR/manifest.yaml"

echo "=== wait for deployments available ==="
kubectl -n "$NS" wait --for=condition=available deploy/drain-default-echo deploy/drain-good deploy/drain-bad --timeout=90s

echo "=== wait for client pod ready ==="
kubectl -n "$NS" wait --for=condition=Ready pod/client --timeout=90s

kubectl -n "$NS" get pods -o wide

echo "=== [1] default duration + who triggers it (drain-default-echo) ==="
POD0=$(kubectl -n "$NS" get pod -l app=drain-default-echo -o jsonpath='{.items[0].metadata.name}')
kubectl -n "$NS" delete pod "$POD0" --wait=false
# poll quickly since the pod object disappears once terminated (default drain ~5s)
for i in $(seq 1 12); do
  OUT=$(kubectl -n "$NS" logs "$POD0" -c istio-proxy 2>&1) || true
  if echo "$OUT" | grep -qiE 'graceful termination|drain'; then
    echo "$OUT" | grep -iE 'graceful termination|drain' | tail -10
    break
  fi
  sleep 1
done

echo "=== [2] annotation override propagation into bootstrap config_dump ==="
kubectl -n "$NS" exec deploy/drain-good -c istio-proxy -- curl -s "localhost:15000/config_dump?mask=bootstrap" | grep -i terminationDrainDuration
kubectl -n "$NS" exec deploy/drain-bad  -c istio-proxy -- curl -s "localhost:15000/config_dump?mask=bootstrap" | grep -i terminationDrainDuration

echo "=== [3] drain-good: grace(40s) > drain(20s) -> in-flight request should complete ==="
( kubectl -n "$NS" exec client -c curl -- curl -s -o /dev/null -w 'drain_good_result=%{http_code} elapsed=%{time_total}\n' \
    "http://drain-good.$NS.svc.homelab.local/delay/12" > /tmp/drain_good.log 2>&1 & )
sleep 1
GPOD=$(kubectl -n "$NS" get pod -l app=drain-good -o jsonpath='{.items[0].metadata.name}')
kubectl -n "$NS" delete pod "$GPOD" --wait=false
sleep 15
cat /tmp/drain_good.log   # expect 200, elapsed ~12s (completed)

echo "=== [4] drain-bad: grace(5s) < drain requirement(20s) -> in-flight request cut short ==="
( kubectl -n "$NS" exec client -c curl -- curl -s -o /dev/null -w 'drain_bad_result=%{http_code} elapsed=%{time_total}\n' --max-time 15 \
    "http://drain-bad.$NS.svc.homelab.local/delay/12" > /tmp/drain_bad.log 2>&1 & )
sleep 1
BPOD=$(kubectl -n "$NS" get pod -l app=drain-bad -o jsonpath='{.items[0].metadata.name}')
kubectl -n "$NS" delete pod "$BPOD" --wait=false
sleep 15
cat /tmp/drain_bad.log   # expect NOT a clean 200/~12s -- cut around grace period (~5s) instead

echo "=== done (namespace will be cleaned up by trap) ==="