mtu

#!/usr/bin/env bash

if oc auth can-i get network/cluster > /dev/null 2>&1; then
  network_type=$(oc get network/cluster -ojson | jq -r .status.networkType)
  if [[ $network_type != "OVNKubernetes" ]]; then
    msg "MTU checks not supported yet for clusters using $network_type"
  else
    # If the crd doesn't exist it will return 0 if you are cluster-admin as you have permissions to get *
    # So it is needed to 'get' the object as well to verify it does exist
    if oc auth can-i get nodenetworkstates.nmstate.io -A > /dev/null 2>&1 && oc get nodenetworkstates.nmstate.io -o jsonpath='{.items[*].metadata.name}' > /dev/null 2>&1; then
      # We need to split the next command using spaces, hence, using standard IFS
      OLDIFS=$IFS
      IFS=$' \t\n'
      for nns in $(oc get nodenetworkstates.nmstate.io -o jsonpath='{.items[*].metadata.name}'); do
        NNS=$(oc get nodenetworkstates.nmstate.io "${nns}" -o json 2> /dev/null)
        BREXMTU=$(echo "${NNS}" | jq '.status.currentState.interfaces[] | select(.name == "br-ex" and .type == "ovs-interface") | .mtu')
        BREXPHYSINT=$(echo "${NNS}" | jq -r '.status.currentState.interfaces[] | select(.name == "br-ex" and .type == "ovs-bridge") | .bridge.port[] | select(.name != "br-ex") | .name')
        PHYSINTMTU=$(echo "${NNS}" | jq ".status.currentState.interfaces[] | select(.name == \"${BREXPHYSINT}\") | .mtu")
        OVNK8SMP0MTU=$(echo "${NNS}" | jq '.status.currentState.interfaces[] | select(.name == "ovn-k8s-mp0") | .mtu')
        msg "${nns} => br-ex:${BREXMTU}, ${BREXPHYSINT}:${PHYSINTMTU}, ovn-k8s-mp0:${OVNK8SMP0MTU}"
      done
      IFS=${OLDIFS}
    else
      if oc auth can-i debug node -A > /dev/null 2>&1 && oc auth can-i get nodes > /dev/null 2>&1; then
        msg "Collecting MTUs... (${BLUE}using oc debug, it can take a while${NOCOLOR}))"
        # shellcheck disable=SC2016
        for node in $(oc get nodes -o go-template='{{range .items}}{{$node := .}}{{range .status.conditions}}{{if eq .type "Ready"}}{{if eq .status "True"}}node/{{$node.metadata.name}}{{"\n"}}{{end}}{{end}}{{end}}{{end}}'); do
          # Get all the information in a single debug to avoid rescheduling unneeded pods
          # then convert the output into an array for easily consumption
          # shellcheck disable=2016
          mapfile -t MTUS < <( oc debug --image="${OCDEBUGIMAGE}" "${node}" -- chroot /host sh -c 'export EXTBR="br-ex"; export OVNBR="ovn-k8s-mp0"; export BMINTERFACE=$(ovs-vsctl list-ports "${EXTBR}" | grep -v patch) ; echo "${BMINTERFACE}"; nmcli -g GENERAL.MTU dev show "${BMINTERFACE}"; nmcli -g GENERAL.MTU dev show "${EXTBR}"; nmcli -g GENERAL.MTU dev show "${OVNBR}"' 2> /dev/null )
          # If the array is empty, something has happened
          if [ ${#MTUS[@]} -eq 0 ]; then
            msg "${YELLOW}Couldn't get MTU settings in ${node}${NOCOLOR}"
          else
            # MTUS[0] = Baremetal interface name
            # MTUS[1] = Baremetal interface MTU
            # MTUS[2] = br-ex MTU
            # MTUS[3] = ovn-k8s-mp0 MTU
            msg "${node} => br-ex:${MTUS[2]}, ${MTUS[0]}:${MTUS[1]}, ovn-k8s-mp0: ${MTUS[3]}"
          fi
        done
      fi
    fi
  fi
else
      msg "Couldn't debug nodes, check permissions" 
fi