refactor: streamline Node.js path configuration in task runner

- Removed redundant home directory retrieval and nvm checks in the configureNodePath method.
- Introduced a new utility function GetNodeModulesPath to centralize the logic for determining the global node_modules path.
- Updated environment variable setup to use the new utility function, improving clarity and maintainability of the code.

Author: Marvin Zhang

core/task/handler/runner.go

@@ -342,36 +342,15 @@ func (r *Runner) startHealthCheck() {
 
 // configureNodePath sets up the Node.js environment paths, handling both nvm and default installations
 func (r *Runner) configureNodePath() {
-	// Get user's home directory
-	home, err := os.UserHomeDir()
-	if err != nil {
-		r.Errorf("error getting user home directory: %v", err)
-		home = "/root" // fallback to root if it can't get home dir
-	}
-
 	// Configure nvm-based Node.js paths
 	envPath := os.Getenv("PATH")
-	nvmPath := filepath.Join(home, ".nvm/versions/node")
-
-	// Check if nvm is being used
-	if utils.Exists(nvmPath) {
-		// Get the current node version from NVM
-		currentVersion := os.Getenv("NVM_BIN")
-		if currentVersion != "" {
-			nodePath := filepath.Dir(currentVersion) + "/lib/node_modules"
-			if !strings.Contains(envPath, nodePath) {
-				_ = os.Setenv("PATH", nodePath+":"+envPath)
-			}
-			_ = os.Setenv("NODE_PATH", nodePath)
-		}
-	} else {
-		// Fallback to default global node_modules path
-		nodePath := "/usr/lib/node_modules"
-		if !strings.Contains(envPath, nodePath) {
-			_ = os.Setenv("PATH", nodePath+":"+envPath)
-		}
-		_ = os.Setenv("NODE_PATH", nodePath)
+
+	// Configure global node_modules path
+	nodePath := utils.GetNodeModulesPath()
+	if !strings.Contains(envPath, nodePath) {
+		_ = os.Setenv("PATH", nodePath+":"+envPath)
 	}
+	_ = os.Setenv("NODE_PATH", nodePath)
 }
 
 // configureEnv sets up the environment variables for the task process, including:

core/utils/config.go

@@ -31,6 +31,7 @@ const (
 	MetadataConfigDirName      = ".crawlab"
 	MetadataConfigName         = "config.json"
 	PyenvRoot                  = "/root/.pyenv"
+	DefaultNodeModulesPath     = "/usr/lib/node_modules"
 )
 
 func IsDev() bool {
@@ -247,3 +248,10 @@ func GetInstallRoot() string {
 	}
 	return DefaultInstallRoot
 }
+
+func GetNodeModulesPath() string {
+	if res := viper.GetString("install.node.path"); res != "" {
+		return res
+	}
+	return DefaultNodeModulesPath
+}