feat: add --wg-endpoint flag to 'uc machine add/init' to specify wireguard endpoint for the machine instead of auto-detecting

internal/cli/flags.go

@@ -1,10 +1,14 @@
 package cli
 
 import (
+	"fmt"
 	"log"
+	"net/netip"
 	"os"
 	"strings"
 
+	"github.com/psviderski/uncloud/internal/machine/api/pb"
+	"github.com/psviderski/uncloud/internal/machine/network"
 	"github.com/spf13/cobra"
 )
 
@@ -34,3 +38,22 @@ func BindEnvToFlag(cmd *cobra.Command, flagName, envVar string) {
 		}
 	}
 }
+
+// ParseWireGuardEndpoints parses a list of endpoint strings into a list of IPPort protobuf messages. Each value can
+// be an IP address, IP:PORT, IPv6, or [IPv6]:PORT. If the port is omitted, the default WireGuard port is used.
+func ParseWireGuardEndpoints(values []string) ([]*pb.IPPort, error) {
+	endpoints := make([]*pb.IPPort, 0, len(values))
+	for _, v := range values {
+		ap, err := netip.ParseAddrPort(v)
+		if err != nil {
+			// Try parsing as a bare IP address and use the default WireGuard port.
+			addr, addrErr := netip.ParseAddr(v)
+			if addrErr != nil {
+				return nil, fmt.Errorf("invalid endpoint '%s': must be IP, IPv6, IP:PORT, or [IPv6]:PORT", v)
+			}
+			ap = netip.AddrPortFrom(addr, network.WireGuardPort)
+		}
+		endpoints = append(endpoints, pb.NewIPPort(ap))
+	}
+	return endpoints, nil
+}