Merge pull request #1414 from yunkon-kim/yunkon-kim-patch-240111

Add a function to check if a network configuration is vaild

src/core/common/netutil/netutil.go

@@ -40,7 +40,7 @@ func init() {
 
 // Models
 type NetworkConfig struct {
-	BaseNetwork Network `json:"baseNetwork"`
+	NetworkConfiguration Network `json:"networkConfiguration"`
 }
 
 // NetworkInterface defines the methods that both Network and NetworkDetails should implement.
@@ -302,3 +302,54 @@ func GetSizeOfHosts(cidrBlock string) (int, error) {
 
 	return CalculateHostCapacity(ipNet)
 }
+
+// ///////////////////////////////////////////////////////////////////
+// ValidateNetwork recursively validates the network and its subnets.
+func ValidateNetwork(network Network) error {
+	// Check if the CIDR block is valid
+	if _, _, err := net.ParseCIDR(network.CIDRBlock); err != nil {
+		return fmt.Errorf("invalid CIDR block '%s': %w", network.CIDRBlock, err)
+	}
+
+	// Check for overlapping subnets within the same network
+	if err := hasOverlappingSubnets(network.Subnets); err != nil {
+		return fmt.Errorf("in network '%s': %w", network.CIDRBlock, err)
+	}
+
+	// Recursively validate each subnet
+	for _, subnet := range network.Subnets {
+		if !isSubnetOf(network.CIDRBlock, subnet.CIDRBlock) {
+			return fmt.Errorf("subnet '%s' is not a valid subnet of '%s'", subnet.CIDRBlock, network.CIDRBlock)
+		}
+		if err := ValidateNetwork(subnet); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// isSubnetOf checks if childCIDR is a subnet of parentCIDR.
+func isSubnetOf(parentCIDR, childCIDR string) bool {
+	_, parentNet, _ := net.ParseCIDR(parentCIDR)
+	_, childNet, _ := net.ParseCIDR(childCIDR)
+	return parentNet.Contains(childNet.IP)
+}
+
+// hasOverlappingSubnets checks if there are overlapping subnets within the same network.
+func hasOverlappingSubnets(subnets []Network) error {
+	for i := 0; i < len(subnets); i++ {
+		for j := i + 1; j < len(subnets); j++ {
+			if cidrOverlap(subnets[i].CIDRBlock, subnets[j].CIDRBlock) {
+				return fmt.Errorf("overlapping subnets found: '%s' and '%s'", subnets[i].CIDRBlock, subnets[j].CIDRBlock)
+			}
+		}
+	}
+	return nil
+}
+
+// cidrOverlap checks if two CIDR blocks overlap.
+func cidrOverlap(cidr1, cidr2 string) bool {
+	_, net1, _ := net.ParseCIDR(cidr1)
+	_, net2, _ := net.ParseCIDR(cidr2)
+	return net1.Contains(net2.IP) || net2.Contains(net1.IP)
+}

src/examples/netutil/netutil.go

@@ -128,76 +128,55 @@ func runExample(cmd *cobra.Command, args []string) {
 	fmt.Printf(" GetSubnets(): %v\n", networkDetails.GetSubnets())
 
 	///////////////////////////////////////////////////////////////////////////////////////////////////
-	fmt.Println("\n(Under development) Network template example")
-	// Define the base network
-	baseNetwork := netutil.Network{
-		CIDRBlock: "10.0.0.0/16",
-		Subnets: []netutil.Network{
-			{
-				// Define a VPC Network
-				CIDRBlock: "10.0.1.0/24",
-				Subnets: []netutil.Network{
-					{
-						// Define a Subnetwork within the VPC
-						CIDRBlock: "10.0.1.0/28",
-					},
-					{
-						// Another Subnetwork within the VPC
-						CIDRBlock: "10.0.1.16/28",
-					},
-				},
-			},
-			{
-				// Another VPC Network
-				CIDRBlock: "10.0.2.0/24",
-				Subnets: []netutil.Network{
-					{
-						// Subnetwork within the second VPC
-						CIDRBlock: "10.0.2.0/28",
-					},
-				},
-			},
-		},
-	}
-
-	fmt.Println("Base Network CIDR:", baseNetwork.CIDRBlock)
-	for i, vpc := range baseNetwork.Subnets {
-		fmt.Printf("VPC Network %d CIDR: %s\n", i+1, vpc.CIDRBlock)
-		for j, subnet := range vpc.Subnets {
-			fmt.Printf("\tSubnetwork %d CIDR: %s\n", j+1, subnet.CIDRBlock)
-		}
-	}
+	fmt.Println("\nValidate a network configuration")
 
-	///////////////////////////////////////////////////////////////////////////////////////////////////
-	fmt.Println("\n(Under development) Design multi-cloud network")
-	jsonData := `{
-        "baseNetwork": {
-            "name": "BaseNetwork1",
+	expectedInput := `{
+        "networkConfiguration": {
+            "name": "BaseNetwork (note - a CIDR block of logical global mutli-cloud network)",
             "cidrBlock": "10.0.0.0/16",
             "subnets": [
                 {
-                    "name": "CloudNetwork1",
+                    "name": "CloudNetwork1 (note - a CIDR block to be assigned to cloud network such as VPC network)",
                     "cidrBlock": "10.0.1.0/24",
                     "subnets": [
                         {"name": "Subnet1", "cidrBlock": "10.0.1.0/26"},
                         {"name": "Subnet2", "cidrBlock": "10.0.1.64/26"},
                         {"name": "Subnet3", "cidrBlock": "10.0.1.128/26"},
                         {"name": "Subnet4", "cidrBlock": "10.0.1.192/26"}
                     ]
+                },
+				{
+                    "name": "CloudNetwork2 (note - a CIDR block to be assigned to cloud network such as VPC network)",
+                    "cidrBlock": "10.0.2.0/24",
+                    "subnets": [
+                        {"name": "Subnet1", "cidrBlock": "10.0.2.0/26"},
+                        {"name": "Subnet2", "cidrBlock": "10.0.2.64/26"},
+                        {"name": "Subnet3", "cidrBlock": "10.0.2.128/26"},
+                        {"name": "Subnet4", "cidrBlock": "10.0.2.192/26"}
+                    ]
                 }
             ]
         }
     }`
+	fmt.Printf("[Expected input]\n%s\n", expectedInput)
 
-	var config netutil.NetworkConfig
-	err = json.Unmarshal([]byte(jsonData), &config)
+	var netConf netutil.NetworkConfig
+	err = json.Unmarshal([]byte(expectedInput), &netConf)
 	if err != nil {
-		log.Fatalf("Error occurred during unmarshaling. Error: %s", err.Error())
+		fmt.Printf("Error occurred during unmarshaling. Error: %s\n", err.Error())
 	}
 
-	prettyConfig, err := json.MarshalIndent(config, "", "   ")
+	network := netConf.NetworkConfiguration
+	pretty, err := json.MarshalIndent(network, "", "   ")
 	if err != nil {
-		log.Fatalf("marshaling error: %s", err)
+		fmt.Printf("marshaling error: %s\n", err)
+	}
+	fmt.Printf("[Network configuration to validate]\n%s\n", string(pretty))
+
+	if err := netutil.ValidateNetwork(network); err != nil {
+		fmt.Println("Network configuration is valid.")
+	} else {
+		fmt.Println("Network configuration is invalid.")
 	}
-	fmt.Printf("[Configuration]\n%s", string(prettyConfig))
+
 }