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_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{