Merge pull request #2 from Brainfinance/factory

Switch to a config and factory based initialization to avoid needless…

Author: jordanebelanger

Package.swift

@@ -5,6 +5,9 @@ import PackageDescription
 
 let package = Package(
     name: "StackdriverLogging",
+    platforms: [
+        .macOS(.v10_14)
+    ],
     products: [
         .library(name: "StackdriverLogging", targets: ["StackdriverLogging"]),
     ],
@@ -13,7 +16,7 @@ let package = Package(
         .package(url: "https://github.com/apple/swift-log.git", from: "1.0.0"),
 
         // Used for non-blocking fileIO
-        .package(url: "https://github.com/apple/swift-nio.git", from: "2.2.0"),
+        .package(url: "https://github.com/apple/swift-nio.git", from: "2.2.0")
     ],
     targets: [
         .target(name: "StackdriverLogging", dependencies: ["NIO", "Logging"]),

README.md

@@ -11,32 +11,26 @@ This Stackdriver `LogHandler` has a dependency on [SwiftNIO](https://github.com/
 ### Swift Package Manager
 
 ```swift
-.package(url: "https://github.com/Brainfinance/StackdriverLogging.git", from:"1.0.1")
+.package(url: "https://github.com/Brainfinance/StackdriverLogging.git", from:"2.0.0")
 ```
 In your target's dependencies add `"StackdriverLogging"` e.g. like this:
 ```swift
 .target(name: "App", dependencies: ["StackdriverLogging"]),
 ```
 
 ## Bootstrapping 
-Here is an example of how a  `StackdriverLogHandler` could be bootstrapped, notice that the `StackdriverLogHandler` initializer will throw if it receives an invalid filepath.  
+A factory `StackdriverLogHandlerFactory` is used to instantiate `StackdriverLogHandler` instances. Before bootstrapping your `LoggingSystem`, you must first call the  `StackdriverLogHandlerFactory.prepare(:)` function with a `StackdriverLoggingConfiguration` to prepare the factory.
+
+Here's an example of how this works:
 
 ```Swift
-LoggingSystem.bootstrap { label -> LogHandler in
-    // ...
-    if label == "Stackdriver" {
-        do {
-            var logHandler = try StackdriverLogHandler(logFilePath: "/var/log/my_app.log")
-            logHandler.logLevel = .error
-            return logHandler
-        } catch {
-            // The logFilePath does not exist or is inacessible, defaulting to a console logger
-            print("Failed to create a StackdriverLogHandler with error: '\(error.localizedDescription)'")
-            return ConsoleLogger()
-        }
-    }
-    // ...
-}    
+try! StackdriverLogHandlerFactory.prepare(with: .init(logFilePath: "/var/log/my-app.log", 
+                                                      defaultLogLevel: .debug,
+                                                      logTimestamps: true))
+LoggingSystem.bootstrap { label in
+    return StackdriverLogHandlerFactory.make()
+}
+
 ```
 ## Logging JSON values using `Logger.MetadataValue`
 To log metadata values as JSON, simply log all JSON values other than `String` as a `Logger.MetadataValue.stringConvertible` and, instead of the usual conversion of your value to a `String` in the log entry, it will keep the original JSON type of your values whenever possible.
@@ -87,7 +81,7 @@ Will log the non pretty-printed representation of:
 ```
 
 ## Stackdriver logging agent + fluentd config 
-You can use this LogHandler in combination with the Stackdriver logging agent https://cloud.google.com/logging/docs/agent/installation and a matching json format
+You must use this LogHandler in combination with the Stackdriver logging agent https://cloud.google.com/logging/docs/agent/installation and a matching json format
 google-fluentd config (/etc/google-fluentd/config.d/example.conf) to automatically send your JSON logs to Stackdriver. 
 
 Here's an example google-fluentd conf file that monitors a json based logfile and send new log entries to Stackdriver:
@@ -107,3 +101,6 @@ Here's an example google-fluentd conf file that monitors a json based logfile an
     tag exampletag
 </source>
 ```
+
+## Future
+A Stackdriver gRPC API based implementation is being considered.