feat: add standard output logger for debug (#16)

Add Standard output logger for debug options

Author: mario-launchdarkly

ExampleApp/ExampleApp/AppDelegate.swift

@@ -9,7 +9,7 @@ let config = { () -> LDConfig in
         autoEnvAttributes: .enabled
     )
     config.plugins = [
-        Observability(options: .init(sessionBackgroundTimeout: 3))
+        Observability(options: .init(sessionBackgroundTimeout: 3, isDebug: true))
     ]
     return config
 }()

ExampleApp/ExampleApp/Instrumentation/Manual/InstrumentationView.swift

@@ -6,6 +6,8 @@ struct InstrumentationView: View {
     var body: some View {
         VStack {
             TraceView()
+            LogsView()
+            Spacer()
         }
         .padding()
     }

ExampleApp/ExampleApp/Instrumentation/Manual/LogsView.swift

@@ -0,0 +1,55 @@
+import SwiftUI
+import LaunchDarklyObservability
+import OpenTelemetryApi
+
+
+struct LogsView: View {
+    @State private var message: String = ""
+    @State private var pressed = false
+    
+    var body: some View {
+        VStack(alignment: .leading, spacing: 4) {
+            Text("Logs")
+                .bold()
+            HStack {
+                TextField(text: $message) {
+                    Text("Message:")
+                }
+                .autocorrectionDisabled(true)
+                .textCase(.lowercase)
+                .textInputAutocapitalization(.never)
+                .textFieldStyle(.roundedBorder)
+                Spacer()
+                Button {
+                    pressed.toggle()
+                } label: {
+                    if pressed {
+                        ProgressView {
+                            Text("...")
+                        }
+                    } else {
+                        Text("Log button pressed")
+                    }
+                }
+                .buttonStyle(.borderedProminent)
+                .accessibilityIdentifier("logsView-send-button")
+                .disabled(message.isEmpty)
+                .task(id: pressed) {
+                    guard pressed else {
+                        return
+                    }
+                    LDObserve.shared.recordLog(
+                        message: message,
+                        severity: .info,
+                        attributes: [
+                            "user_id": .string("1234"),
+                            "action": .string("logsView-send-button-pressed")
+                        ]
+                    )
+                    pressed.toggle()
+                    message = ""
+                }
+            }
+        }
+    }
+}

ExampleApp/ExampleApp/Instrumentation/Manual/TraceView.swift

@@ -16,6 +16,7 @@ struct TraceView: View {
                 TextField(text: $name) {
                     Text("Span name:")
                 }
+                .autocorrectionDisabled(true)
                 .textCase(.lowercase)
                 .textInputAutocapitalization(.never)
                 .textFieldStyle(.roundedBorder)

Sources/Observability/InstrumentationManager.swift

@@ -1,5 +1,7 @@
 import Foundation
 
+import os
+
 import UIKit.UIWindow
 
 import OpenTelemetrySdk
@@ -19,7 +21,7 @@ private let metricsPath = "/v1/metrics"
 final class InstrumentationManager {
     private let sdkKey: String
     private let options: Options
-    let otelLogger: Logger?
+    let otelLogger: OpenTelemetryApi.Logger?
     let otelTracer: Tracer?
     let otelMeter: (any Meter)?
     public let otelBatchLogRecordProcessor: BatchLogRecordProcessor?
@@ -59,12 +61,25 @@ final class InstrumentationManager {
                 }
             }
             .map { url in
-                SamplingLogExporterDecorator(
-                    exporter: OtlpHttpLogExporter(
-                        endpoint: url,
-                        envVarHeaders: options.customHeaders
-                    ),
-                    sampler: sampler
+                MultiLogRecordExporter(
+                    logRecordExporters: options.isDebug ? [
+                        SamplingLogExporterDecorator(
+                            exporter: OtlpHttpLogExporter(
+                                endpoint: url,
+                                envVarHeaders: options.customHeaders
+                            ),
+                            sampler: sampler
+                        ),
+                        LDStdoutExporter(loggerName: options.loggerName)
+                    ] : [
+                        SamplingLogExporterDecorator(
+                            exporter: OtlpHttpLogExporter(
+                                endpoint: url,
+                                envVarHeaders: options.customHeaders
+                            ),
+                            sampler: sampler
+                        )
+                    ]
                 )
             }
             .map { exporter in

Sources/Observability/LDStdoutExporter.swift

@@ -0,0 +1,43 @@
+import Foundation
+
+import os
+
+import OpenTelemetrySdk
+import OpenTelemetryApi
+
+import Common
+
+
+final class LDStdoutExporter: LogRecordExporter {
+    private let loggerName: String
+    
+    init(loggerName: String) {
+        self.loggerName = loggerName
+    }
+    
+    public func forceFlush(
+        explicitTimeout: TimeInterval?
+    ) -> ExportResult {
+        .success
+    }
+    
+    public func shutdown(
+        explicitTimeout: TimeInterval?
+    ) {
+        
+    }
+    
+    public func export(
+        logRecords: [ReadableLogRecord],
+        explicitTimeout: TimeInterval?
+    ) -> ExportResult {
+
+        for log in logRecords {
+            guard let message = JSON.stringify(log) else { continue }
+            
+            os_log("%{public}@", log: .default, type: .info, message)
+        }
+        
+        return .success
+    }
+}