Enable change gateway

cmd/start.go

@@ -45,6 +45,7 @@ Run 'colima template' to set the default configurations or 'colima start --edit'
 		"  colima start --arch aarch64\n" +
 		"  colima start --dns 1.1.1.1 --dns 8.8.8.8\n" +
 		"  colima start --dns-host example.com=1.2.3.4\n" +
+		"  colima start --gateway-address 192.168.6.2\n" +
 		"  colima start --kubernetes --k3s-arg='\"--disable=coredns,servicelb,traefik,local-storage,metrics-server\"'",
 	Args: cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
@@ -210,6 +211,9 @@ func init() {
 		}
 	}
 
+	// Gateway Address
+	startCmd.Flags().StringVar(&startCmdArgs.Network.GatewayAddress, "gateway-address", "192.168.5.2", "gateway address")
+
 	// binfmt
 	startCmd.Flags().BoolVar(&startCmdArgs.Flags.Binfmt, "binfmt", true, binfmtDesc)
 
@@ -518,6 +522,9 @@ func prepareConfig(cmd *cobra.Command) {
 	if !cmd.Flag("dns-host").Changed {
 		startCmdArgs.Network.DNSHosts = current.Network.DNSHosts
 	}
+	if !cmd.Flag("gateway-address").Changed {
+		startCmdArgs.Network.GatewayAddress = current.Network.GatewayAddress
+	}
 	if !cmd.Flag("env").Changed {
 		startCmdArgs.Env = current.Env
 	}

config/config.go

@@ -88,6 +88,7 @@ type Network struct {
 	Mode            string            `yaml:"mode"` // shared, bridged
 	BridgeInterface string            `yaml:"interface"`
 	PreferredRoute  bool              `yaml:"preferredRoute"`
+	GatewayAddress  string            `yaml:"gatewayAddress"`
 }
 
 // Mount is volume mount

config/configmanager/configmanager.go

@@ -2,6 +2,7 @@ package configmanager
 
 import (
 	"fmt"
+	"net"
 	"os"
 	"strings"
 
@@ -80,6 +81,12 @@ func ValidateConfig(c config.Config) error {
 		return fmt.Errorf("invalid port forwarder: '%s'", c.PortForwarder)
 	}
 
+	if c.Network.GatewayAddress != "" {
+		if err := validateGatewayAddress(c.Network.GatewayAddress); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
@@ -108,3 +115,27 @@ func Teardown() error {
 	}
 	return nil
 }
+
+// Validates that gateway is a valid IPv4 address and that the last octet is “2”.
+// Lima uses the last octet as 2 for gateways.
+func validateGatewayAddress(gateway string) error {
+	ip := net.ParseIP(gateway)
+	if ip == nil {
+		return fmt.Errorf("gateway %q is not a valid IP address", gateway)
+	}
+	ip4 := ip.To4()
+	if ip4 == nil {
+		return fmt.Errorf("gateway %q is not IPv4", gateway)
+	}
+
+	parts := strings.Split(gateway, ".")
+	if len(parts) != 4 {
+		return fmt.Errorf("gateway %q does not have 4 octets", gateway)
+	}
+
+	if parts[3] != "2" {
+		return fmt.Errorf("the last octet of gateway %q is not 2", gateway)
+	}
+
+	return nil
+}

embedded/defaults/colima.yaml

@@ -107,6 +107,15 @@ network:
   # Default: false
   hostAddresses: false
 
+  # Custom gateway address for the virtual machine.
+  # The last octet needs to be 2.
+  #
+  # EXAMPLE
+  # gatewayAddress: 192.168.10.2
+  #
+  # Default: 192.168.5.2
+  gatewayAddress: 192.168.5.2
+
 # ===================================================================== #
 # ADVANCED CONFIGURATION
 # ===================================================================== #

environment/vm/lima/dns.go

@@ -9,15 +9,10 @@ import (
 )
 
 const (
-	localhostAddr = "127.0.0.1"
-	gatewayAddr   = "192.168.5.2"
+	localhostAddr         = "127.0.0.1"
+	defaultGatewayAddress = "192.168.5.2"
 )
 
-var dnsHosts = map[string]string{
-	"host.docker.internal": gatewayAddr,
-	"host.lima.internal":   gatewayAddr,
-}
-
 func hasDnsmasq(l *limaVM) bool {
 	// check if dnsmasq is installed
 	return l.RunQuiet("sh", "-c", `apt list | grep 'dnsmasq\/' | grep '\[installed'`) == nil
@@ -30,6 +25,18 @@ func (l *limaVM) setupDNS(conf config.Config) error {
 		return nil
 	}
 
+	// use custom gateway address
+	var gatewayAddr = defaultGatewayAddress
+	customGatewayAddress := conf.Network.GatewayAddress
+	if customGatewayAddress != "" {
+		gatewayAddr = customGatewayAddress
+	}
+
+	var dnsHosts = map[string]string{
+		"host.docker.internal": gatewayAddr,
+		"host.lima.internal":   gatewayAddr,
+	}
+
 	internalIP := limautil.InternalIPAddress(config.CurrentProfile().ID)
 
 	// extra dns entries

environment/vm/lima/lima.go

@@ -111,7 +111,8 @@ func (l *limaVM) Start(ctx context.Context, conf config.Config) error {
 		return yamlutil.WriteYAML(l.limaConf, confFile)
 	})
 
-	a.Add(l.writeNetworkFile)
+	a.Add(func() error { return l.writeNetworkFile(conf) })
+
 	a.Add(func() error {
 		return l.host.Run(limactl, "start", "--tty=false", confFile)
 	})
@@ -166,7 +167,7 @@ func (l *limaVM) resume(ctx context.Context, conf config.Config) error {
 		return err
 	})
 
-	a.Add(l.writeNetworkFile)
+	a.Add(func() error { return l.writeNetworkFile(conf) })
 
 	a.Stage("starting")
 	a.Add(func() error {

environment/vm/lima/limautil/network.go

@@ -51,3 +51,15 @@ func getIPAddress(profileID, interfaceName string) string {
 	_ = cmd.Run()
 	return strings.TrimSpace(buf.String())
 }
+
+type LimaNetworkConfig struct {
+	Mode    string `yaml:"mode"`
+	Gateway string `yaml:"gateway"`
+	Netmask string `yaml:"netmask"`
+}
+
+type LimaNetwork struct {
+	Networks struct {
+		UserV2 LimaNetworkConfig `yaml:"user-v2"`
+	} `yaml:"networks"`
+}

environment/vm/lima/network.go

@@ -11,15 +11,33 @@ import (
 	"github.com/abiosoft/colima/environment/vm/lima/limautil"
 	"github.com/abiosoft/colima/util"
 	"github.com/sirupsen/logrus"
+	"gopkg.in/yaml.v3"
 )
 
-func (l *limaVM) writeNetworkFile() error {
+func (l *limaVM) writeNetworkFile(conf config.Config) error {
 	networkFile := limautil.NetworkFile()
 	embeddedFile, err := embedded.Read("network/networks.yaml")
 	if err != nil {
 		return fmt.Errorf("error reading embedded network config file: %w", err)
 	}
 
+	// use custom gateway address
+	gatewayAddress := conf.Network.GatewayAddress
+	if gatewayAddress != "" {
+		var cfg limautil.LimaNetwork
+		if err := yaml.Unmarshal(embeddedFile, &cfg); err != nil {
+			return fmt.Errorf("error unmarshalling the `networks.yaml` file: %w", err)
+		}
+
+		cfg.Networks.UserV2.Gateway = gatewayAddress
+
+		out, err := yaml.Marshal(&cfg)
+		if err != nil {
+			return fmt.Errorf("error marshalling the `networks.yaml` file: %w", err)
+		}
+		embeddedFile = out
+	}
+
 	// if there are no running instances, clear network directory
 	if instances, err := limautil.RunningInstances(); err == nil && len(instances) == 0 {
 		if err := os.RemoveAll(limautil.NetworkAssetsDirectory()); err != nil {