Allow log path specification

Sources/App/Management/Configuration.swift

@@ -33,6 +33,22 @@ struct Configuration {
 
     /// The authentication tokens to access the metrics
     let monitoringTokens: Set<String>
+    
+    /// The path to the folder where the metric logs are stored
+    ///
+    /// If no path is provided, then a folder `logs` in the resources directory is created
+    /// If the path is relative, then it is assumed relative to the resources directory
+    let logPath: String?
+    
+    func logURL(possiblyRelativeTo resourcesDirectory: URL) -> URL {
+        guard let logPath else {
+            return resourcesDirectory.appendingPathComponent("logs")
+        }
+        guard !logPath.hasPrefix("/") else {
+            return .init(fileURLWithPath: logPath)
+        }
+        return resourcesDirectory.appendingPathComponent(logPath)
+    }
 }
 
 extension Configuration {