Homelabv4/infrastructure/crowdsec/manifests/firewall-bouncer.yaml

# CrowdSec Firewall Bouncer - nftables enforcement on each node
# Blocks malicious IPs before they reach Cilium eBPF processing
# Requires: hostNetwork + privileged (nftables management)
# Image: community Docker build of cs-firewall-bouncer (no official image exists)
#
# api_url points at a headless Service (below), not the normal ClusterIP
# crowdsec-service. Cilium's socketLB is configured hostNamespaceOnly (see
# infrastructure/cilium/values.yaml, needed for Istio ambient compatibility),
# which means socket-level Service translation/policy enforcement applies to
# host-namespace traffic - and this bouncer runs hostNetwork: true, so it IS
# host-namespace traffic. Connecting to a ClusterIP VIP from there gets an
# immediate EPERM on connect() (confirmed live 2026-08-17, been broken since
# this DaemonSet was first deployed 2026-03-03 - not a regression from any
# recent change). A headless Service resolves straight to pod IPs via DNS -
# no VIP, nothing for socket-LB to intercept - and connects cleanly.
---
apiVersion: v1
kind: Service
metadata:
  name: crowdsec-lapi-headless
  namespace: crowdsec
spec:
  clusterIP: None
  selector:
    k8s-app: crowdsec
    type: lapi
    version: v1
  ports:
    - name: lapi
      port: 8080
      protocol: TCP
      targetPort: 8080
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: crowdsec-firewall-bouncer-config
  namespace: crowdsec
data:
  crowdsec-firewall-bouncer.yaml: |
    mode: nftables
    update_frequency: 10s
    log_mode: stdout
    log_level: info
    api_url: http://crowdsec-lapi-headless.crowdsec.svc:8080/
    api_key: ${API_KEY}
    insecure_skip_verify: false
    disable_ipv6: false
    deny_action: DROP
    deny_log: true
    deny_log_prefix: "crowdsec: "
    supported_decisions_types:
      - ban
    blacklists_ipv4: crowdsec-blacklists
    blacklists_ipv6: crowdsec6-blacklists
    nftables:
      ipv4:
        enabled: true
        set-only: false
        table: crowdsec
        chain: crowdsec-chain
        priority: -10
      ipv6:
        enabled: true
        set-only: false
        table: crowdsec6
        chain: crowdsec6-chain
        priority: -10
    nftables_hooks:
      - input
      - forward
    prometheus:
      enabled: true
      listen_addr: 0.0.0.0
      listen_port: 60601
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: crowdsec-firewall-bouncer
  namespace: crowdsec
  labels:
    app: crowdsec-firewall-bouncer
spec:
  selector:
    matchLabels:
      app: crowdsec-firewall-bouncer
  template:
    metadata:
      labels:
        app: crowdsec-firewall-bouncer
    spec:
      hostNetwork: true
      dnsPolicy: ClusterFirstWithHostNet
      tolerations:
        - operator: Exists
      initContainers:
        # Render env vars in config template
        - name: render-config
          image: docker.io/library/busybox:1.36
          securityContext:
            runAsUser: 10000
            runAsGroup: 10000
            runAsNonRoot: true
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            capabilities:
              drop: ["ALL"]
            seccompProfile:
              type: RuntimeDefault
          command: ["/bin/sh", "-c"]
          args:
            - |
              sed "s|\${API_KEY}|${API_KEY}|g" /config-template/crowdsec-firewall-bouncer.yaml > /config/crowdsec-firewall-bouncer.yaml
          env:
            - name: API_KEY
              valueFrom:
                secretKeyRef:
                  name: crowdsec-bouncer-key
                  key: api-key
          volumeMounts:
            - name: config-template
              mountPath: /config-template
            - name: config-rendered
              mountPath: /config
      containers:
        - name: bouncer
          image: ghcr.io/shgew/cs-firewall-bouncer-docker:v0.0.34-patch1
          command:
            - /usr/local/bin/crowdsec-firewall-bouncer
            - -c
            - /config/crowdsec-firewall-bouncer.yaml
          resources:
            requests:
              cpu: 10m
              memory: 32Mi
            limits:
              memory: 64Mi
          securityContext:
            privileged: true
            capabilities:
              add:
                - NET_ADMIN
                - NET_RAW
          volumeMounts:
            - name: config-rendered
              mountPath: /config
              readOnly: true
            - name: nftables-lock
              mountPath: /run
      volumes:
        - name: config-template
          configMap:
            name: crowdsec-firewall-bouncer-config
        - name: config-rendered
          emptyDir: {}
        - name: nftables-lock
          hostPath:
            path: /run
            type: Directory
---
apiVersion: v1
kind: Service
metadata:
  name: crowdsec-firewall-bouncer-metrics
  namespace: crowdsec
  labels:
    app: crowdsec-firewall-bouncer
spec:
  selector:
    app: crowdsec-firewall-bouncer
  ports:
    - name: metrics
      port: 60601
      targetPort: 60601
      protocol: TCP
---
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
  name: crowdsec-firewall-bouncer
  namespace: crowdsec
  labels:
    app: crowdsec-firewall-bouncer
    release: kube-prometheus-stack
spec:
  selector:
    matchLabels:
      app: crowdsec-firewall-bouncer
  endpoints:
    - port: metrics
      interval: 30s