Add logging to file

Sources/App/Log.swift

@@ -16,5 +16,27 @@ private let df: DateFormatter = {
 
 func log(_ message: String, file: String = #file, line: Int = #line) {
     let date = df.string(from: Date())
-    print("[\(date)][\(file.components(separatedBy: "/").last ?? file):\(line)] \(message)")
+    let m = "[\(date)][\(file.components(separatedBy: "/").last ?? file):\(line)] \(message)"
+    print(m)
+    Log.write("\n" + m)
+}
+
+enum Log {
+    
+    static func set(logFile: String) throws {
+        let url = URL(fileURLWithPath: logFile)
+        if !FileManager.default.fileExists(atPath: logFile) {
+            try "Log started".write(to: url, atomically: false, encoding: .utf8)
+        }
+        file = FileHandle(forWritingAtPath: logFile)
+    }
+    
+    static func write(_ message: String) {
+        guard let f = file else {
+            return
+        }
+        f.write(message.data(using: .utf8)!)
+    }
+    
+    private static var file: FileHandle?
 }

Sources/App/routes.swift

@@ -6,6 +6,8 @@ import SQLite
 
 private let baseFolder = URL(fileURLWithPath: "/caps")
 
+private let logFile = baseFolder.appendingPathComponent("logs/server.log").path
+
 private let publicFolder = baseFolder.appendingPathComponent("Public")
 
 private let imageFolder = publicFolder.appendingPathComponent("images")
@@ -65,6 +67,8 @@ private func count(of cap: Int) throws -> Int {
 /// [Learn More →](https://docs.vapor.codes/3.0/getting-started/structure/#routesswift)
 public func routes(_ router: Router) throws {
     
+    try Log.set(logFile: logFile)
+    
     // Get the name of a cap
     router.getCatching("name", Int.parameter) { request -> Data in
         let cap = try request.parameters.next(Int.self)