feat(monitoring): restrict syslog ingress to the sending networks

alloy-syslog accepted syslog from any world source. Senders seen in Hubble and Loki over the last 7 days: switches and APs on Management, SLZB coordinators and edge hosts on IoT, and the UDM, which sources from its k8s-ingress address 10.2.47.1. The LB is ETP=Local, so those client addresses reach the pod. Refs S28-19 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-07 11:14:54 +01:00
2 changed files with 11 additions and 42 deletions
@@ -1,13 +1,6 @@
-# Targeted carve-out: alloy-syslog needs world ingress on the syslog
-# ports specifically. The Service is ETP=Cluster, so external syslog
-# senders (Proxmox, LXC hosts, network gear) hit the LB IP, get DNAT'd
-# to an alloy pod, and get SNAT'd to the receiving node's cilium_host
-# address. Cilium then sees the source as `world-ipv4` identity (the
-# cilium_host IP isn't a known endpoint), NOT `host` — so the broad
-# monitoring CNP's `fromEntities: host` rule doesn't catch it.
-#
-# Scoped via endpointSelector so this only widens ingress on the
-# alloy-syslog pod, not the whole namespace.
+# Syslog senders reaching the alloy-syslog LB (ETP=Local, client address
+# reaches the pod): network gear on Management, the SLZB coordinators on
+# IoT, and the UDM itself, which sources from its k8s-ingress address.
 apiVersion: cilium.io/v2
 kind: CiliumNetworkPolicy
 metadata:
@@ -19,8 +12,10 @@ spec:
      app.kubernetes.io/instance: alloy-syslog
      app.kubernetes.io/name: alloy
  ingress:
-    - fromEntities:
-        - world
+    - fromCIDRSet:
+        - cidrGroupRef: net-management
+        - cidrGroupRef: net-iot
+        - cidrGroupRef: net-k8s-ingress
      toPorts:
        - ports:
            - port: "514"
@@ -112,7 +112,7 @@ spec:
            - { type: 136, family: IPv6 }
            - { type: 143, family: IPv6 }
 ---
-# FTP from the scanners (IoT and Privat) to the ftp-scanner pod.
+# Allow FTP access (from scanners on the LAN) to the ftp-scanner pod.
 apiVersion: cilium.io/v2
 kind: CiliumNetworkPolicy
 metadata:
@@ -123,24 +123,8 @@ spec:
    matchLabels:
      app.kubernetes.io/name: ftp-scanner
  ingress:
-    - fromCIDRSet:
-        - cidrGroupRef: net-iot
-        - cidrGroupRef: net-privat
-      toPorts:
-        - ports:
-            - port: "21"
-              protocol: TCP
-            - port: "21100"
-              protocol: TCP
-            - port: "21101"
-              protocol: TCP
-            - port: "21102"
-              protocol: TCP
-            - port: "21103"
-              protocol: TCP
-            - port: "21104"
-              protocol: TCP
    - fromEntities:
+        - world
        - host
        - remote-node
      toPorts:
@@ -158,7 +142,7 @@ spec:
            - port: "21104"
              protocol: TCP
 ---
-# Allow Syncthing peer-to-peer sync from Privat and VPN.
+# Allow Syncthing peer-to-peer sync from the LAN/world.
 # - 22000 TCP+QUIC: actual sync traffic between peers.
 # - 21027 UDP: local-discovery broadcast packets from peers on the LAN.
 # UI (8384) is intentionally NOT listed — authentik-gate-sync generates the
@@ -173,18 +157,8 @@ spec:
    matchLabels:
      app.kubernetes.io/name: syncthing
  ingress:
-    - fromCIDRSet:
-        - cidrGroupRef: net-privat
-        - cidrGroupRef: net-vpn
-      toPorts:
-        - ports:
-            - port: "22000"
-              protocol: TCP
-            - port: "22000"
-              protocol: UDP
-            - port: "21027"
-              protocol: UDP
    - fromEntities:
+        - world
        - host
        - remote-node
      toPorts: