t.Fatalf("%s.  Unable to get IP addresses of this host.", err)
	}

	for _, addr := range addrs {
		var ip net.IP
		switch v := addr.(type) {
		case *net.IPNet:
			ip = v.IP
		case *net.IPAddr:
			ip = v.IP
		}

		if ip.To4() != nil {
			localIP4.Add(ip.String())
		}
	}

	// Filter ipList by IPs those do not start with '127.'.

#
# Arguments:
#   $1 - VM name
#   $2 - VM zone
#   $3 - external static IP; if empty will use an ephemeral IP address.
function attach-external-ip() {
  local NAME=${1}
  local ZONE=${2}
  local IP_ADDR=${3:-}
  local ACCESS_CONFIG_NAME
  ACCESS_CONFIG_NAME=$(gcloud compute instances describe "${NAME}" \
    --project "${PROJECT}" --zone "${ZONE}" \
    --format="value(networkInterfaces[0].accessConfigs[0].name)")

	ldr.SetAttrLocal(s, true)
	ctxt.xdefine("runtime.egcdata", sym.SRODATA, ldr.SymAddr(s)+ldr.SymSize(s))
	ldr.SetSymSect(ldr.LookupOrCreateSym("runtime.egcdata", 0), ldr.SymSect(s))

	s = ldr.LookupOrCreateSym("runtime.gcbss", 0)
	ldr.SetAttrLocal(s, true)
	ctxt.xdefine("runtime.egcbss", sym.SRODATA, ldr.SymAddr(s)+ldr.SymSize(s))
	ldr.SetSymSect(ldr.LookupOrCreateSym("runtime.egcbss", 0), ldr.SymSect(s))