rbd: parse IP address

The address we get from ceph
contains the ip in the format
of 10.244.0.1:0/2686266785 we
need to extract the client IP
from this address, we already
have a helper to extract it,
This makes the helper more generic
can be reused by multiple packages
in the fence controller.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

internal/csi-addons/networkfence/fencing.go

@@ -217,31 +217,7 @@ func isIPInCIDR(ctx context.Context, ip, cidr string) bool {
 func (ac *activeClient) fetchIP() (string, error) {
 	// example: "inst": "client.4305 172.21.9.34:0/422650892",
 	// then returning value will be 172.21.9.34
-	clientInfo := ac.Inst
-
-	// Attempt to extract the IP address using a regular expression
-	// the regular expression aims to match either a complete IPv6
-	// address or a complete IPv4 address follows by any prefix (v1 or v2)
-	// if exists
-	// (?:v[0-9]+:): this allows for an optional prefix starting with "v"
-	// followed by one or more digits and a colon.
-	// The ? outside the group makes the entire prefix section optional.
-	// (?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}: this allows to check for
-	// standard IPv6 address.
-	// |: Alternation operator to allow matching either the IPv6 pattern
-	// with a prefix or the IPv4 pattern.
-	// '(?:\d+\.){3}\d+: This part matches a standard IPv4 address.
-	re := regexp.MustCompile(`(?:v[0-9]+:)?([0-9a-fA-F]{1,4}(:[0-9a-fA-F]{1,4}){7}|(?:\d+\.){3}\d+)`)
-	ipMatches := re.FindStringSubmatch(clientInfo)
-
-	if len(ipMatches) > 0 {
-		ip := net.ParseIP(ipMatches[1])
-		if ip != nil {
-			return ip.String(), nil
-		}
-	}
-
-	return "", fmt.Errorf("failed to extract IP address, incorrect format: %s", clientInfo)
+	return ParseClientIP(ac.Inst)
 }
 
 func (ac *activeClient) fetchID() (int, error) {
@@ -526,3 +502,29 @@ func (nf *NetworkFence) parseBlocklistForCIDR(ctx context.Context, blocklist, ci
 
 	return matchingHosts
 }
+
+func ParseClientIP(addr string) (string, error) {
+	// Attempt to extract the IP address using a regular expression
+	// the regular expression aims to match either a complete IPv6
+	// address or a complete IPv4 address follows by any prefix (v1 or v2)
+	// if exists
+	// (?:v[0-9]+:): this allows for an optional prefix starting with "v"
+	// followed by one or more digits and a colon.
+	// The ? outside the group makes the entire prefix section optional.
+	// (?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}: this allows to check for
+	// standard IPv6 address.
+	// |: Alternation operator to allow matching either the IPv6 pattern
+	// with a prefix or the IPv4 pattern.
+	// '(?:\d+\.){3}\d+: This part matches a standard IPv4 address.
+	re := regexp.MustCompile(`(?:v[0-9]+:)?([0-9a-fA-F]{1,4}(:[0-9a-fA-F]{1,4}){7}|(?:\d+\.){3}\d+)`)
+	ipMatches := re.FindStringSubmatch(addr)
+
+	if len(ipMatches) > 0 {
+		ip := net.ParseIP(ipMatches[1])
+		if ip != nil {
+			return ip.String(), nil
+		}
+	}
+
+	return "", fmt.Errorf("failed to extract IP address, incorrect format: %s", addr)
+}

internal/csi-addons/networkfence/fencing_test.go

@@ -257,3 +257,45 @@ listed 1 entries`,
 		})
 	}
 }
+
+func TestParseClientIP(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name    string
+		addr    string
+		want    string
+		wantErr bool
+	}{
+		{
+			name:    "IPv4 address",
+			addr:    "10.244.0.1:0/2686266785",
+			want:    "10.244.0.1",
+			wantErr: false,
+		},
+		{
+			name:    "IPv6 address",
+			addr:    "2001:0db8:85a3:0000:0000:8a2e:0370:7334:0/2686266785",
+			want:    "2001:db8:85a3::8a2e:370:7334",
+			wantErr: false,
+		},
+		{
+			name:    "Invalid address",
+			addr:    "invalid",
+			want:    "",
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			got, err := ParseClientIP(tt.addr)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ParseClientIP() error = %v, wantErr %v", err, tt.wantErr)
+			}
+
+			if got != tt.want {
+				t.Errorf("ParseClientIP() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

internal/csi-addons/rbd/network_fence.go

@@ -155,13 +155,23 @@ func (fcs *FenceControllerServer) GetFenceClients(
 		return nil, status.Errorf(codes.Internal, "failed to get client address: %s", err)
 	}
 
+	// The example address we get is 10.244.0.1:0/2686266785 from
+	// which we need to extract the IP address.
+	addr, err := nf.ParseClientIP(address)
+	if err != nil {
+		return nil, status.Errorf(codes.Internal, "failed to parse client address: %s", err)
+	}
+
+	// adding /32 to the IP address to make it a CIDR block.
+	addr += "/32"
+
 	resp := &fence.GetFenceClientsResponse{
 		Clients: []*fence.ClientDetails{
 			{
 				Id: fsID,
 				Addresses: []*fence.CIDR{
 					{
-						Cidr: address,
+						Cidr: addr,
 					},
 				},
 			},