# kind-config.yaml
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
  - role: control-plane
  - role: worker
  - role: worker

kind create cluster --name routing-lab --config kind-config.yaml

kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.14.8/config/manifests/metallb-native.yaml
kubectl wait -n metallb-system --for=condition=ready pod --selector=app=metallb --timeout=90s

# kind 도커 네트워크 서브넷을 먼저 확인한다
docker network inspect -f '{{.IPAM.Config}}' kind

# metallb-pool.yaml
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  name: kind-pool
  namespace: metallb-system
spec:
  addresses:
    - 172.18.255.200-172.18.255.250   # docker network inspect 결과에 맞춰 조정
---
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  name: kind-l2
  namespace: metallb-system
spec:
  ipAddressPools:
    - kind-pool

kubectl apply -f metallb-pool.yaml

helm install eg oci://docker.io/envoyproxy/gateway-helm --version v1.8.3 \
  -n envoy-gateway-system --create-namespace

kubectl wait -n envoy-gateway-system deployment/envoy-gateway \
  --for=condition=Available --timeout=5m

# gatewayclass.yaml
apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
  name: eg
spec:
  controllerName: gateway.envoyproxy.io/gatewayclass-controller

# gateway.yaml
apiVersion: gateway.networking.k8s.io/v1
kind: Gateway
metadata:
  name: eg
  namespace: default
spec:
  gatewayClassName: eg
  listeners:
    - name: http
      protocol: HTTP
      port: 80
      allowedRoutes:
        namespaces:
          from: All        # 다른 네임스페이스의 HTTPRoute 도 붙을 수 있게

kubectl apply -f gatewayclass.yaml -f gateway.yaml
kubectl get gateway -n default eg

# echo.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: routing-lab
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: echo-a
  namespace: routing-lab
  labels:
    app.kubernetes.io/name: echo-a
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: echo-a
  template:
    metadata:
      labels:
        app.kubernetes.io/name: echo-a
    spec:
      containers:
        - name: echo
          image: ealen/echo-server:latest
          ports:
            - containerPort: 80
          resources:
            requests:
              cpu: 10m
              memory: 48Mi
            limits:
              memory: 128Mi
---
apiVersion: v1
kind: Service
metadata:
  name: echo-a
  namespace: routing-lab
spec:
  selector:
    app.kubernetes.io/name: echo-a
  ports:
    - port: 80
      targetPort: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: echo-b
  namespace: routing-lab
  labels:
    app.kubernetes.io/name: echo-b
spec:
  replicas: 1
  selector:
    matchLabels:
      app.kubernetes.io/name: echo-b
  template:
    metadata:
      labels:
        app.kubernetes.io/name: echo-b
    spec:
      containers:
        - name: echo
          image: ealen/echo-server:latest
          ports:
            - containerPort: 80
          resources:
            requests:
              cpu: 10m
              memory: 48Mi
            limits:
              memory: 128Mi
---
apiVersion: v1
kind: Service
metadata:
  name: echo-b
  namespace: routing-lab
spec:
  selector:
    app.kubernetes.io/name: echo-b
  ports:
    - port: 80
      targetPort: 80

kubectl apply -f echo.yaml
kubectl wait -n routing-lab --for=condition=Available deploy/echo-a deploy/echo-b --timeout=90s

H='Host: routing.test'; U=127.0.0.1:8080

probe() {
  local method=${1} path=${2}
  local r code pod
  r=$(curl -s -X "$method" -w '\n%{http_code}' -H "$H" "$U$path")
  code=$(tail -1 <<<"$r")
  pod=$(sed '$d' <<<"$r" | jq -r '.environment.HOSTNAME' 2>/dev/null)
  printf '%-8s %-40s %s %s\n' "$method" "$path" "$code" "${pod:--}"
}

# 경로만 보고 싶을 때 (rewrite 검증용)
rewritten() {
  curl -s -H "$H" "$U$1" | jq -r '.http.originalUrl'
}

kubectl get svc -n envoy-gateway-system
kubectl port-forward -n envoy-gateway-system svc/envoy-default-eg-<해시> 8080:80

# route-regex.yaml
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: regex-only
  namespace: routing-lab
spec:
  parentRefs:
    - name: eg
      namespace: default        # Gateway 와 ns 가 다르면 명시 필수
  hostnames:
    - "routing.test"
  rules:
    - matches:
        - path:
            type: RegularExpression
            value: '^/v3/customer/bookings/\d+/coupons'
      backendRefs:
        - name: echo-b
          port: 80

kubectl apply -f route-regex.yaml

# 적용 확인 : RE2 가 거부하는 문법이면 여기서 Accepted=False 로 뜬다
kubectl get httproute -n routing-lab regex-only \
  -o jsonpath='{.status.parents[*].conditions[*]}' | jq .

for p in \
  '/v3/customer/bookings/123/coupons' \
  '/v3/customer/bookings/123/coupons/456' \
  '/v3/customer/bookings/123/coupons?x=1' \
  '/api/v3/customer/bookings/123/coupons' \
  '/v3/customer/bookings/abc/coupons' ; do
  probe GET "$p"
done

# route-priority.yaml
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: prio-regex-prefix
  namespace: routing-lab
spec:
  parentRefs:
    - name: eg
      namespace: default
  hostnames:
    - "routing.test"
  rules:
    # (1) 넓은 prefix → echo-a
    - matches:
        - path:
            type: PathPrefix
            value: /v3/customer
      backendRefs:
        - name: echo-a
          port: 80
    # (2) 좁은 정규식 → echo-b
    - matches:
        - path:
            type: RegularExpression
            value: '^/v3/customer/bookings/\d+/coupons.*'
      backendRefs:
        - name: echo-b
          port: 80

kubectl delete -f route-regex.yaml
kubectl apply -f route-priority.yaml

probe GET /v3/customer/bookings/123/coupons
probe GET /v3/customer/bookings/123/coupons/456
probe GET /v3/customer/profile

# route-priority-c.yaml
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: prio-long-prefix
  namespace: routing-lab
spec:
  parentRefs:
    - name: eg
      namespace: default
  hostnames:
    - "routing.test"
  rules:
    # 긴 prefix (25자) → echo-a
    - matches:
        - path:
            type: PathPrefix
            value: /v3/customer/bookings/123
      backendRefs:
        - name: echo-a
          port: 80
    # 정규식 → echo-b
    - matches:
        - path:
            type: RegularExpression
            value: '^/v3/customer/bookings/\d+/coupons.*'
      backendRefs:
        - name: echo-b
          port: 80

# route-priority-d.yaml
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: prio-regex-regex
  namespace: routing-lab
spec:
  parentRefs:
    - name: eg
      namespace: default
  hostnames:
    - "routing.test"
  rules:
    # (1) 넓은 정규식 → echo-a
    - matches:
        - path:
            type: RegularExpression
            value: '^/v3/customer/bookings/.*'
      backendRefs:
        - name: echo-a
          port: 80
    # (2) 좁은 정규식 → echo-b
    - matches:
        - path:
            type: RegularExpression
            value: '^/v3/customer/bookings/\d+/coupons.*'
      backendRefs:
        - name: echo-b
          port: 80

# route-rewrite.yaml
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: HTTPRouteFilter
metadata:
  name: rw-no-tail
  namespace: routing-lab
spec:
  urlRewrite:
    path:
      type: ReplaceRegexMatch
      replaceRegexMatch:
        pattern: '^/nt/bookings/(\d+)/coupons'
        substitution: '/coupons/\1'
---
apiVersion: gateway.envoyproxy.io/v1alpha1
kind: HTTPRouteFilter
metadata:
  name: rw-with-tail
  namespace: routing-lab
spec:
  urlRewrite:
    path:
      type: ReplaceRegexMatch
      replaceRegexMatch:
        pattern: '^/wt/bookings/(\d+)/coupons(.*)'
        substitution: '/coupons/\1\2'
---
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: rewrite-capture
  namespace: routing-lab
spec:
  parentRefs:
    - name: eg
      namespace: default
  hostnames:
    - "routing.test"
  rules:
    # 꼬리 미캡처
    - matches:
        - path:
            type: RegularExpression
            value: '^/nt/bookings/\d+/coupons.*'
      filters:
        - type: ExtensionRef
          extensionRef:
            group: gateway.envoyproxy.io
            kind: HTTPRouteFilter
            name: rw-no-tail
      backendRefs:
        - name: echo-b
          port: 80
    # 꼬리 캡처
    - matches:
        - path:
            type: RegularExpression
            value: '^/wt/bookings/\d+/coupons.*'
      filters:
        - type: ExtensionRef
          extensionRef:
            group: gateway.envoyproxy.io
            kind: HTTPRouteFilter
            name: rw-with-tail
      backendRefs:
        - name: echo-b
          port: 80

kubectl apply -f route-rewrite.yaml

for p in \
  '/nt/bookings/123/coupons' \
  '/nt/bookings/123/coupons/456' \
  '/wt/bookings/123/coupons/456' ; do
  printf '%-34s -> %s\n' "$p" "$(rewritten "$p")"
done

# route-method.yaml
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: method-match
  namespace: routing-lab
spec:
  parentRefs:
    - name: eg
      namespace: default
  hostnames:
    - "routing.test"
  rules:
    # E-1: 정규식 + GET → echo-a
    - matches:
        - path:
            type: RegularExpression
            value: '^/v3/backoffice/wages.*'
          method: GET
      backendRefs:
        - name: echo-a
          port: 80
    # E-2: 같은 정규식 + POST → echo-b
    - matches:
        - path:
            type: RegularExpression
            value: '^/v3/backoffice/wages.*'
          method: POST
      backendRefs:
        - name: echo-b
          port: 80
    # F-1: 메서드 조건 없음 → echo-a
    - matches:
        - path:
            type: PathPrefix
            value: /w2
      backendRefs:
        - name: echo-a
          port: 80
    # F-2: 같은 경로 + POST → echo-b
    - matches:
        - path:
            type: PathPrefix
            value: /w2
          method: POST
      backendRefs:
        - name: echo-b
          port: 80

kubectl apply -f route-method.yaml

for m in GET POST PATCH DELETE OPTIONS; do probe $m /v3/backoffice/wages/123; done
for m in GET POST; do probe $m /w2/anything; done

rules:
  # 승격 권한이 필요한 쓰기 (POST)
  - matches:
      - path: { type: PathPrefix, value: /v3/backoffice/wages }
        method: POST
    backendRefs:
      - name: echo-b
        port: 80
  # 나머지 전부 : OPTIONS 를 여기서 받는다
  - matches:
      - path: { type: PathPrefix, value: /v3/backoffice/wages }
    backendRefs:
      - name: echo-a
        port: 80

# ✅
kubectl port-forward -n envoy-gateway-system svc/envoy-default-eg-<해시> 8080:80

# ❌ connection refused
kubectl port-forward -n envoy-gateway-system pod/envoy-default-eg-<해시>-xxx 8080:80

# ✅ 파드 이름
jq -r '.environment.HOSTNAME'

# ❌ 요청 Host 헤더
jq -r '.host.hostname'

kubectl get pods -n routing-lab \
  -o jsonpath='{range .items[*]}{.metadata.name}{" "}{.spec.containers[0].image}{"\n"}{end}'

kubectl delete ns routing-lab