juwan-backend/deploy/k8s/envoy/envoy.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: envoy-config
  namespace: juwan
data:
  envoy.yaml: |
    static_resources:
      listeners:
      - name: ingress_http
        address:
          socket_address:
            address: 0.0.0.0
            port_value: 8080
        filter_chains:
        - filters:
          - name: envoy.filters.network.http_connection_manager
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
              stat_prefix: ingress_http
              codec_type: AUTO
              generate_request_id: true
              use_remote_address: true
              route_config:
                name: local_route
                virtual_hosts:
                - name: juwan_services
                  domains: ["*"]
                  routes:
                  - match:
                      path: /healthz
                    direct_response:
                      status: 200
                      body:
                        inline_string: ok
                  - match:
                      prefix: /api/email
                    route:
                      cluster: email_api_cluster
                      timeout: 30s
                  - match:
                      prefix: /api/users
                    route:
                      cluster: user_api_cluster
                      timeout: 30s
                  - match:
                      prefix: /
                    direct_response:
                      status: 404
                      body:
                        inline_string: "gateway route not found"
              http_filters:
              - name: envoy.filters.http.lua
                typed_config:
                  "@type": type.googleapis.com/envoy.extensions.filters.http.lua.v3.Lua
                  inline_code: |
                    local TOKEN_COOKIE = "csrf_token"
                    local GUARD_COOKIE = "csrf_guard"
                    local TOKEN_HEADER = "x-csrf-token"
                    local GUARD_HEADER = "x-csrf-guard"

                    local seeded = false

                    local function seed_random()
                      if seeded then
                        return
                      end
                      seeded = true
                      math.randomseed(os.time())
                    end

                    local function split_cookie(header)
                      local out = {}
                      if not header then
                        return out
                      end
                      for pair in string.gmatch(header, "([^;]+)") do
                        local key, value = string.match(pair, "^%s*([^=]+)=?(.*)$")
                        if key ~= nil and value ~= nil then
                          out[string.lower(key)] = value
                        end
                      end
                      return out
                    end

                    local function is_safe_method(method)
                      return method == "GET" or method == "HEAD" or method == "OPTIONS"
                    end

                    local function build_token(request_id)
                      seed_random()
                      local rnd = tostring(math.random(100000, 999999))
                      local rid = request_id or "rid"
                      return tostring(os.time()) .. "-" .. rid .. "-" .. rnd
                    end

                    function envoy_on_request(request_handle)
                      local headers = request_handle:headers()
                      local method = headers:get(":method")

                      local cookie_header = headers:get("cookie")
                      local cookies = split_cookie(cookie_header)
                      local csrf_token_cookie = cookies[TOKEN_COOKIE]
                      local csrf_guard_cookie = cookies[GUARD_COOKIE]

                      request_handle:streamInfo():dynamicMetadata():set("csrf", "need_set_token_cookie", csrf_token_cookie == nil or csrf_token_cookie == "")
                      request_handle:streamInfo():dynamicMetadata():set("csrf", "need_set_guard_cookie", csrf_guard_cookie == nil or csrf_guard_cookie == "")

                      if csrf_token_cookie == nil or csrf_token_cookie == "" then
                        csrf_token_cookie = build_token(headers:get("x-request-id"))
                        request_handle:streamInfo():dynamicMetadata():set("csrf", "token_value", csrf_token_cookie)
                      else
                        request_handle:streamInfo():dynamicMetadata():set("csrf", "token_value", csrf_token_cookie)
                      end

                      if csrf_guard_cookie == nil or csrf_guard_cookie == "" then
                        csrf_guard_cookie = build_token(headers:get("x-request-id"))
                        request_handle:streamInfo():dynamicMetadata():set("csrf", "guard_value", csrf_guard_cookie)
                      else
                        request_handle:streamInfo():dynamicMetadata():set("csrf", "guard_value", csrf_guard_cookie)
                      end

                      if is_safe_method(method) then
                        return
                      end

                      local csrf_token_header = headers:get(TOKEN_HEADER)
                      local csrf_guard_header = headers:get(GUARD_HEADER)

                      if csrf_token_header == nil or csrf_guard_header == nil then
                        request_handle:respond(
                          {[":status"] = "403", ["content-type"] = "application/json"},
                          '{"code":403,"message":"missing csrf headers"}'
                        )
                        return
                      end

                      if csrf_token_cookie == nil or csrf_guard_cookie == nil then
                        request_handle:respond(
                          {[":status"] = "403", ["content-type"] = "application/json"},
                          '{"code":403,"message":"missing csrf cookies"}'
                        )
                        return
                      end

                      if csrf_token_header ~= csrf_token_cookie or csrf_guard_header ~= csrf_guard_cookie then
                        request_handle:respond(
                          {[":status"] = "403", ["content-type"] = "application/json"},
                          '{"code":403,"message":"csrf token mismatch"}'
                        )
                        return
                      end
                    end

                    function envoy_on_response(response_handle)
                      local metadata = response_handle:streamInfo():dynamicMetadata():get("csrf")
                      if metadata == nil then
                        return
                      end

                      local token_value = metadata["token_value"]
                      local guard_value = metadata["guard_value"]

                      if metadata["need_set_token_cookie"] == true and token_value ~= nil and token_value ~= "" then
                        response_handle:headers():add(
                          "set-cookie",
                          TOKEN_COOKIE .. "=" .. token_value .. "; Path=/; SameSite=Strict"
                        )
                      end

                      if metadata["need_set_guard_cookie"] == true and guard_value ~= nil and guard_value ~= "" then
                        response_handle:headers():add(
                          "set-cookie",
                          GUARD_COOKIE .. "=" .. guard_value .. "; Path=/; SameSite=Strict"
                        )
                      end
                    end
              - name: envoy.filters.http.router
                typed_config:
                  "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

      clusters:
      - name: user_api_cluster
        connect_timeout: 2s
        type: STRICT_DNS
        lb_policy: ROUND_ROBIN
        load_assignment:
          cluster_name: user_api_cluster
          endpoints:
          - lb_endpoints:
            - endpoint:
                address:
                  socket_address:
                    address: user-api-svc.juwan.svc.cluster.local
                    port_value: 8888
      - name: email_api_cluster
        connect_timeout: 2s
        type: STRICT_DNS
        lb_policy: ROUND_ROBIN
        load_assignment:
          cluster_name: email_api_cluster
          endpoints:
          - lb_endpoints:
            - endpoint:
                address:
                  socket_address:
                    address: email-api-svc.juwan.svc.cluster.local
                    port_value: 8888

    admin:
      access_log_path: /tmp/admin_access.log
      address:
        socket_address:
          address: 0.0.0.0
          port_value: 9901

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: envoy-gateway
  namespace: juwan
  labels:
    app: envoy-gateway
spec:
  replicas: 2
  revisionHistoryLimit: 5
  selector:
    matchLabels:
      app: envoy-gateway
  template:
    metadata:
      labels:
        app: envoy-gateway
    spec:
      containers:
        - name: envoy
          image: envoyproxy/envoy:v1.31-latest
          imagePullPolicy: IfNotPresent
          command: ["/usr/local/bin/envoy"]
          args:
            - "-c"
            - "/etc/envoy/envoy.yaml"
            - "--log-level"
            - "info"
          ports:
            - containerPort: 8080
              name: http
            - containerPort: 9901
              name: admin
          livenessProbe:
            httpGet:
              path: /healthz
              port: 8080
            initialDelaySeconds: 10
            periodSeconds: 15
          readinessProbe:
            httpGet:
              path: /healthz
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 10
          resources:
            requests:
              cpu: 100m
              memory: 128Mi
            limits:
              cpu: 500m
              memory: 512Mi
          volumeMounts:
            - name: envoy-config
              mountPath: /etc/envoy
      volumes:
        - name: envoy-config
          configMap:
            name: envoy-config

---
apiVersion: v1
kind: Service
metadata:
  name: envoy-gateway
  namespace: juwan
spec:
  selector:
    app: envoy-gateway
  ports:
    - name: http
      port: 80
      targetPort: 8080
    - name: admin
      port: 9901
      targetPort: 9901
  type: ClusterIP