apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: default-deny-ingress-egress
  namespace: cosmic-clash
spec:
  podSelector: {}
  policyTypes: [Ingress, Egress]
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: control-plane-allowed-flows
  namespace: cosmic-clash
spec:
  podSelector:
    matchLabels:
      app.kubernetes.io/name: control-plane
  policyTypes: [Ingress, Egress]
  ingress:
    - from:
        - namespaceSelector: {}
          podSelector:
            matchLabels:
              app.kubernetes.io/name: edge-gateway
      ports:
        - protocol: TCP
          port: 8080
    # Allocated game servers are control-plane clients too: roster fetch,
    # registration, connection receipts, shutdown acknowledgement and result
    # submission all target this port. Their egress was already permitted, but
    # without a matching ingress rule every one of those calls was dropped, so
    # no allocated match could complete even inside the cluster.
    - from:
        - podSelector:
            matchLabels:
              app.kubernetes.io/name: game-server
      ports:
        - protocol: TCP
          port: 8080
  egress:
    - to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: data
          podSelector:
            matchLabels:
              app.kubernetes.io/name: postgres
      ports:
        - protocol: TCP
          port: 5432
    - to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: data
          podSelector:
            matchLabels:
              app.kubernetes.io/name: redis
      ports:
        - protocol: TCP
          port: 6379
    - ports:
        - protocol: UDP
          port: 53
        - protocol: TCP
          port: 53
      to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: kube-system
          podSelector:
            matchLabels:
              k8s-app: kube-dns
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: game-server-allowed-egress
  namespace: cosmic-clash
spec:
  podSelector:
    matchLabels:
      app.kubernetes.io/name: game-server
  policyTypes: [Egress]
  egress:
    - to:
        - podSelector:
            matchLabels:
              app.kubernetes.io/name: control-plane
      ports:
        - protocol: TCP
          port: 8080
    - ports:
        - protocol: UDP
          port: 53
        - protocol: TCP
          port: 53
      to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: kube-system
          podSelector:
            matchLabels:
              k8s-app: kube-dns
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allocator-allowed-flows
  namespace: cosmic-clash
spec:
  podSelector:
    matchLabels:
      app.kubernetes.io/name: allocator
  policyTypes: [Ingress, Egress]
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: monitoring
          podSelector:
            matchLabels:
              app.kubernetes.io/name: prometheus
      ports:
        - protocol: TCP
          port: 9091
  egress:
    - to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: data
          podSelector:
            matchLabels:
              app.kubernetes.io/name: postgres
      ports:
        - protocol: TCP
          port: 5432
    # The kubernetes.default Service endpoint is implementation-specific and
    # may be a control-plane/node IP that cannot be selected by pod labels.
    # Keep API egress portable while limiting it to TLS only.
    - ports:
        - protocol: TCP
          port: 443
    - ports:
        - protocol: UDP
          port: 53
        - protocol: TCP
          port: 53
      to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: kube-system
          podSelector:
            matchLabels:
              k8s-app: kube-dns
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: maintenance-allowed-egress
  namespace: cosmic-clash
spec:
  podSelector:
    matchLabels:
      app.kubernetes.io/name: maintenance
  policyTypes: [Egress]
  egress:
    - to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: data
          podSelector:
            matchLabels:
              app.kubernetes.io/name: postgres
      ports:
        - protocol: TCP
          port: 5432
    - ports:
        - protocol: UDP
          port: 53
        - protocol: TCP
          port: 53
      to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: kube-system
          podSelector:
            matchLabels:
              k8s-app: kube-dns
---
# Public players connect straight to the allocated GameServer's UDP port; the
# control plane only ever hands out its address. The namespace-wide default
# deny blocked that ingress entirely, so an allocated server was unreachable
# from the internet and no matchmade game could be joined.
#
# The source cannot be narrowed by selector: these peers are player machines
# outside the cluster. It is narrowed instead to exactly one protocol and port
# on exactly the game-server pods, and the game server admits a peer only with
# a valid signed join authorisation for its own match.
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: game-server-allowed-ingress
  namespace: cosmic-clash
spec:
  podSelector:
    matchLabels:
      app.kubernetes.io/name: game-server
  policyTypes:
    - Ingress
  ingress:
    - ports:
        - protocol: UDP
          port: 7777
---
# The matcher reads queued candidates and writes proposals. It exposes nothing
# and talks to nobody but its two datastores.
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: matcher-allowed-egress
  namespace: cosmic-clash
spec:
  podSelector:
    matchLabels:
      app.kubernetes.io/name: matcher
  policyTypes:
    - Egress
  egress:
    - to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: data
          podSelector:
            matchLabels:
              app.kubernetes.io/name: postgres
      ports:
        - protocol: TCP
          port: 5432
    - to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: data
          podSelector:
            matchLabels:
              app.kubernetes.io/name: redis
      ports:
        - protocol: TCP
          port: 6379
    - to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: kube-system
          podSelector:
            matchLabels:
              k8s-app: kube-dns
      ports:
        - protocol: UDP
          port: 53
        - protocol: TCP
          port: 53