feat: add CLI connector for unix domain socket (#186)

* feat: Add cli connector for unix domain socket

* Update cmd/uncloud/main.go

---------

Co-authored-by: Pasha Sviderski <me@psviderski.name>

internal/cli/config/connection.go

@@ -22,10 +22,12 @@ type MachineConnection struct {
 	SSHKeyFile string         `yaml:"ssh_key_file,omitempty"`
 	// TCP is the address and port of the machine's API server.
 	// The pointer is used to omit the field when not set. Otherwise, yaml marshalling includes an empty object.
-	TCP       *netip.AddrPort `yaml:"tcp,omitempty"`
-	Host      string          `yaml:"host,omitempty"`
-	PublicKey secret.Secret   `yaml:"public_key,omitempty"`
-	MachineID string          `yaml:"machine_id,omitempty"`
+	TCP *netip.AddrPort `yaml:"tcp,omitempty"`
+	// Unix is the path to the machine's API unix socket.
+	Unix      string        `yaml:"unix,omitempty"`
+	Host      string        `yaml:"host,omitempty"`
+	PublicKey secret.Secret `yaml:"public_key,omitempty"`
+	MachineID string        `yaml:"machine_id,omitempty"`
 }
 
 func (c MachineConnection) String() string {
@@ -35,6 +37,8 @@ func (c MachineConnection) String() string {
 		return "ssh+cli://" + string(c.SSHCLI)
 	} else if c.TCP != nil && c.TCP.IsValid() {
 		return fmt.Sprintf("tcp://%s", c.TCP)
+	} else if c.Unix != "" {
+		return fmt.Sprintf("unix://%s", c.Unix)
 	}
 	return "unknown connection"
 }
@@ -50,12 +54,15 @@ func (c *MachineConnection) Validate() error {
 	if c.TCP != nil && c.TCP.IsValid() {
 		setCount++
 	}
+	if c.Unix != "" {
+		setCount++
+	}
 
 	if setCount == 0 {
-		return errors.New("no connection method specified (ssh, ssh_cli, or tcp required)")
+		return errors.New("no connection method specified (ssh, ssh_cli, tcp, or unix required)")
 	}
 	if setCount > 1 {
-		return errors.New("only one connection method allowed per connection (ssh, ssh_cli, or tcp)")
+		return errors.New("only one connection method allowed per connection (ssh, ssh_cli, tcp, or unix)")
 	}
 
 	return nil

internal/cli/config/connection_test.go

@@ -53,6 +53,13 @@ func TestMachineConnection_String(t *testing.T) {
 			},
 			want: "tcp://10.0.0.1:8080",
 		},
+		{
+			name: "unix connection",
+			conn: MachineConnection{
+				Unix: "/run/uncloud/uncloud.sock",
+			},
+			want: "unix:///run/uncloud/uncloud.sock",
+		},
 		{
 			name: "no connection",
 			conn: MachineConnection{},
@@ -112,6 +119,13 @@ func TestMachineConnection_Validate(t *testing.T) {
 			},
 			wantErr: false,
 		},
+		{
+			name: "unix only - valid",
+			conn: MachineConnection{
+				Unix: "/path/to/socket",
+			},
+			wantErr: false,
+		},
 		{
 			name:    "no connection method - error",
 			conn:    MachineConnection{},
@@ -127,6 +141,15 @@ func TestMachineConnection_Validate(t *testing.T) {
 			wantErr: true,
 			errMsg:  "only one connection method allowed",
 		},
+		{
+			name: "ssh and unix - error",
+			conn: MachineConnection{
+				SSH:  "user@host",
+				Unix: "/path/to/socket",
+			},
+			wantErr: true,
+			errMsg:  "only one connection method allowed",
+		},
 		{
 			name: "ssh and tcp - error",
 			conn: MachineConnection{

internal/cli/connect.go

@@ -73,6 +73,8 @@ func connectCluster(ctx context.Context, conn config.MachineConnection) (*client
 		useSSHCLI = true
 	} else if conn.TCP != nil && conn.TCP.IsValid() {
 		return client.New(ctx, connector.NewTCPConnector(*conn.TCP))
+	} else if conn.Unix != "" {
+		return client.New(ctx, connector.NewUnixConnector(conn.Unix))
 	} else {
 		return nil, errors.New("connection configuration is invalid")
 	}