####################################################################################################
# this daemonset configures each minikube or KinD node to route to the multus public net
# it is not suitable for production
####################################################################################################
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: host-net-config
  labels:
    app: host-net-config
spec:
  selector:
    matchLabels:
      app: host-net-config
  updateStrategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 100 # allow updating all at once
  template:
    metadata:
      labels:
        app: host-net-config
    spec:
      hostNetwork: true
      tolerations:
        # also run on control plane nodes for KinD testing
        - key: "node-role.kubernetes.io/control-plane"
          operator: "Exists"
      terminationGracePeriodSeconds: 0 # allow updating/deleting immediately
      containers:
        - name: test
          image: jonlabelle/network-tools
          env:
            - name: IFACE_NAME
              value: eth0 # IFACE_NAME
          command:
            - sh
            - -x
            - -c
          args:
            - |
              IFACE='$(IFACE_NAME)'

              NODE_PUBLIC_NET_IP_FIRST3='192.168.29'
              NET_ATT_DEF_PUBLIC_NET_CIDR='192.168.20.0/24'

              # get the last part of the interface's IP addr
              ip -4 addr show $IFACE
              ip_cidr="$(ip -4 addr show $IFACE | grep inet | awk '{print $2}')" # e.g., 192.168.100.3/24
              ip="${ip_cidr%/*}" # e.g., 192.168.100.3
              last="${ip##*.}" # e.g., 3

              # add a shim to connect IFACE to the macvlan public network, with a static IP
              # avoid IP conflicts by re-using the last part of the existing IFACE IP
              ip link add public-shim link ${IFACE} type macvlan mode bridge
              ip addr add ${NODE_PUBLIC_NET_IP_FIRST3}.${last}/24 dev public-shim
              ip link set public-shim up
              ip route add ${NET_ATT_DEF_PUBLIC_NET_CIDR} dev public-shim

              ip addr show $IFACE
              ip addr show public-shim
              ip route show

              sleep infinity
          resources: {}
          securityContext:
            capabilities:
              add: ["NET_ADMIN"]