client: Add incus-user support

Signed-off-by: Stéphane Graber <[email protected]>

client/connection.go

@@ -171,20 +171,8 @@ func ConnectIncusUnixWithContext(ctx context.Context, path string, args *Connect
 
 	ctxConnected, ctxConnectedCancel := context.WithCancel(context.Background())
 
-	// Initialize the client struct
-	server := ProtocolIncus{
-		ctx:                ctx,
-		httpBaseURL:        *httpBaseURL,
-		httpUnixPath:       path,
-		httpProtocol:       "unix",
-		httpUserAgent:      args.UserAgent,
-		ctxConnected:       ctxConnected,
-		ctxConnectedCancel: ctxConnectedCancel,
-		eventConns:         make(map[string]*websocket.Conn),
-		eventListeners:     make(map[string][]*EventListener),
-	}
-
 	// Determine the socket path
+	var projectName string
 	if path == "" {
 		path = os.Getenv("INCUS_SOCKET")
 		if path == "" {
@@ -194,9 +182,32 @@ func ConnectIncusUnixWithContext(ctx context.Context, path string, args *Connect
 			}
 
 			path = filepath.Join(incusDir, "unix.socket")
+			userPath := filepath.Join(incusDir, "unix.socket.user")
+			if !util.PathIsWritable(path) && util.PathIsWritable(userPath) {
+				// Handle the use of incus-user.
+				path = userPath
+
+				// When using incus-user, the project list is typically restricted.
+				// So let's try to be smart about the project we're using.
+				projectName = fmt.Sprintf("user-%d", os.Geteuid())
+			}
 		}
 	}
 
+	// Initialize the client struct
+	server := ProtocolIncus{
+		ctx:                ctx,
+		httpBaseURL:        *httpBaseURL,
+		httpUnixPath:       path,
+		httpProtocol:       "unix",
+		httpUserAgent:      args.UserAgent,
+		ctxConnected:       ctxConnected,
+		ctxConnectedCancel: ctxConnectedCancel,
+		eventConns:         make(map[string]*websocket.Conn),
+		eventListeners:     make(map[string][]*EventListener),
+		project:            projectName,
+	}
+
 	// Setup the HTTP client
 	httpClient, err := unixHTTPClient(args, path)
 	if err != nil {