Move tracer to Configuration to support tracer config changes after swizzle (#783)

Move tracer to UrlSessionInstrumentationConfiguration

Author: nhart12

Sources/Instrumentation/URLSession/URLSessionInstrumentation.swift

@@ -43,8 +43,6 @@ public class URLSessionInstrumentation {
   ]
   .compactMap { NSClassFromString($0) }
 
-  public private(set) var tracer: Tracer
-
   public var startedRequestSpans: [Span] {
     var spans = [Span]()
     URLSessionLogger.runningSpansQueue.sync {
@@ -55,7 +53,6 @@ public class URLSessionInstrumentation {
 
   public init(configuration: URLSessionInstrumentationConfiguration) {
     self.configuration = configuration
-    tracer = OpenTelemetry.instance.tracerProvider.get(instrumentationName: "NSURLSession", instrumentationVersion: "0.0.1")
     injectInNSURLClasses()
   }
 

Sources/Instrumentation/URLSession/URLSessionInstrumentationConfiguration.swift

@@ -25,7 +25,8 @@ public struct URLSessionInstrumentationConfiguration {
               receivedResponse: ((URLResponse, DataOrFile?, Span) -> Void)? = nil,
               receivedError: ((Error, DataOrFile?, HTTPStatus, Span) -> Void)? = nil,
               delegateClassesToInstrument: [AnyClass]? = nil,
-              baggageProvider: ((inout URLRequest, Span?) -> (Baggage)?)? = nil) {
+              baggageProvider: ((inout URLRequest, Span?) -> (Baggage)?)? = nil,
+              tracer: Tracer? = nil) {
     self.shouldRecordPayload = shouldRecordPayload
     self.shouldInstrument = shouldInstrument
     self.shouldInjectTracingHeaders = shouldInjectTracingHeaders
@@ -37,8 +38,12 @@ public struct URLSessionInstrumentationConfiguration {
     self.receivedError = receivedError
     self.delegateClassesToInstrument = delegateClassesToInstrument
     self.baggageProvider = baggageProvider
+    self.tracer = tracer ??
+      OpenTelemetry.instance.tracerProvider.get(instrumentationName: "NSURLSession", instrumentationVersion: "0.0.1")
   }
 
+  public var tracer: Tracer
+ 
   // Instrumentation Callbacks
 
   /// Implement this callback to filter which requests you want to instrument, all by default

Sources/Instrumentation/URLSession/URLSessionLogger.swift

@@ -70,7 +70,7 @@ class URLSessionLogger {
     if let customSpanName = instrumentation.configuration.nameSpan?(request) {
       spanName = customSpanName
     }
-    let spanBuilder = instrumentation.tracer.spanBuilder(spanName: spanName)
+    let spanBuilder = instrumentation.configuration.tracer.spanBuilder(spanName: spanName)
     spanBuilder.setSpanKind(spanKind: .client)
     attributes.forEach {
       spanBuilder.setAttribute(key: $0.key, value: $0.value)