Allow log path specification

Sources/App/Config.swift

@@ -13,6 +13,22 @@ struct Config {
 
     /// The authentication tokens to use for monitoring of the service
     let authenticationTokens: 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 Config: Codable {

Sources/App/configure.swift

@@ -24,7 +24,11 @@ enum ServerError: Error {
 // configures your application
 public func configure(_ app: Application) throws {
     let storageFolder = URL(fileURLWithPath: app.directory.resourcesDirectory)
-    let logFolder = storageFolder.appendingPathComponent("logs")
+    
+    let configUrl = storageFolder.appendingPathComponent("config.json")
+    let config = try Config(loadFrom: configUrl)
+    
+    let logFolder = config.logURL(possiblyRelativeTo: storageFolder)
     
     let monitor = MetricObserver(logFileFolder: logFolder, logMetricId: "sesame.log")
     MetricObserver.standard = monitor
@@ -34,9 +38,6 @@ public func configure(_ app: Application) throws {
         _ = try await status.update(.initializing)
     }
 
-    let configUrl = storageFolder.appendingPathComponent("config.json")
-    let config = try Config(loadFrom: configUrl)
-
     app.http.server.configuration.port = config.port
 
     let keyFile = storageFolder.appendingPathComponent(config.keyFileName)