cmd/microcloud: Show a warning if the OVN underlay, OVN uplink, Micro…

…Ceph cluster network, MicroCloud public network share traffic on the same network interface

Signed-off-by: Gabriel Mougard <[email protected]>

SQUASH with cmd/microcloud: Show a warning if the OVN underlay network and the MicroCeph cluster network share traffic on the same network interface

Signed-off-by: Gabriel Mougard <[email protected]>

cmd/microcloud/main_init.go

@@ -525,19 +525,83 @@ func (c *initConfig) validateSystems(s *service.Handler) (err error) {
 			continue
 		}
 
-		_, subnet, err := net.ParseCIDR(sys.MicroCephInternalNetworkSubnet)
+		ovnUnderlayIP := net.ParseIP(sys.OVNGeneveAddr)
+		if ovnUnderlayIP == nil {
+			return fmt.Errorf("OVN underlay IP %q is invalid", sys.OVNGeneveAddr)
+		}
+
+		// Get the UPLINK network's gateway IP. This is used to check for interface collisions and print eventual warnings
+		// to the user.
+		var ovnUplinkIP net.IP
+		var err error
+		for _, network := range c.systems[s.Name].Networks {
+			if network.Type == "physical" && network.Name == service.DefaultUplinkNetwork {
+				if network.Config["ipv4.gateway"] != "" {
+					ovnUplinkIP, _, err = net.ParseCIDR(network.Config["ipv4.gateway"])
+					if err != nil {
+						return fmt.Errorf("Failed to parse gateway IPv4 for UPLINK network %q: %w", service.DefaultUplinkNetwork, err)
+					}
+				}
+
+				if ovnUplinkIP == nil && network.Config["ipv6.gateway"] != "" {
+					ovnUplinkIP, _, err = net.ParseCIDR(network.Config["ipv6.gateway"])
+					if err != nil {
+						return fmt.Errorf("Failed to parse gateway IPv6 for UPLINK network %q: %w", service.DefaultUplinkNetwork, err)
+					}
+				}
+
+				if ovnUplinkIP == nil {
+					return fmt.Errorf("Failed to find gateway IP for UPLINK network %q", service.DefaultUplinkNetwork)
+				}
+
+				break
+			}
+		}
+
+		internalCephIP, subnet, err := net.ParseCIDR(sys.MicroCephInternalNetworkSubnet)
 		if err != nil {
-			return fmt.Errorf("Failed to parse available network interface CIDR address: %q: %w", subnet, err)
+			return fmt.Errorf("Failed to parse available network interface CIDR address for internal Ceph network: %q: %w", subnet, err)
 		}
 
-		underlayIP := net.ParseIP(sys.OVNGeneveAddr)
-		if underlayIP == nil {
-			return fmt.Errorf("OVN underlay IP %q is invalid", sys.OVNGeneveAddr)
+		// Check for interface collisions
+		allInterfaces := map[string]*ipWithIface{
+			"Ceph cluster network": {ifaceName: sys.MicroCephInternalNetworkIface, ip: internalCephIP},
+			"OVN underlay":         {ifaceName: sys.OVNGeneveIface, ip: ovnUnderlayIP},
+			"OVN uplink":           {ifaceName: sys.OVNUplinkIface, ip: ovnUplinkIP},
+		}
+
+		// The public Ceph network is not always present (partially disaggregated setup) but we still
+		// wish to check for interface collisions between OVN and the Ceph cluster network.
+		// If it is present though, add it to the list of interfaces to check for collisions.
+		if sys.MicroCephPublicNetworkSubnet != "" {
+			publicCephIP, subnet, err := net.ParseCIDR(sys.MicroCephPublicNetworkSubnet)
+			if err != nil {
+				return fmt.Errorf("Failed to parse available network interface CIDR address for public Ceph network: %q: %w", subnet, err)
+			}
+
+			allInterfaces["Ceph public network"] = &ipWithIface{ifaceName: sys.MicroCephPublicNetworkIface, ip: publicCephIP}
 		}
 
-		if subnet.Contains(underlayIP) {
-			fmt.Printf("Warning: OVN underlay IP (%s) is shared with the Ceph cluster network (%s)\n", underlayIP.String(), subnet.String())
+		interfaceCollision := false
+		for netNameLeft, ipWithIfaceLeft := range allInterfaces {
+			for netNameRight, ipWithIfaceRight := range allInterfaces {
+				// Skip self-comparison and already processed pairs
+				// (e.g. if we already compared "A vs B", we don't need to compare "B vs A").
+				if netNameLeft >= netNameRight {
+					continue
+				}
+
+				if ipWithIfaceLeft.ifaceName == ipWithIfaceRight.ifaceName {
+					if !interfaceCollision {
+						interfaceCollision = true
+					}
+
+					fmt.Printf("Warning: %s (IP: %s) is shared on the same network interface %q with the %s (IP: %s)\n", netNameLeft, ipWithIfaceLeft.ip.String(), ipWithIfaceLeft.ifaceName, netNameRight, ipWithIfaceRight.ip.String())
+				}
+			}
+		}
 
+		if interfaceCollision {
 			break
 		}
 	}