[ch91505] Dynamic header configuration (#128)

Allow dynamic configuration of http headers through LDConfig.headerDelegate

Cartfile

@@ -1 +1 @@
-github "launchdarkly/swift-eventsource" ~> 1.1.0
+github "launchdarkly/swift-eventsource" ~> 1.2.0

LaunchDarkly.podspec

@@ -35,6 +35,6 @@ Pod::Spec.new do |ld|
   ld.swift_version = '5.0'
 
   ld.subspec 'Core' do |es|
-    es.dependency 'LDSwiftEventSource', '1.1.0'
+    es.dependency 'LDSwiftEventSource', '1.2.0'
   end
 end

LaunchDarkly.xcodeproj/project.pbxproj

@@ -571,7 +571,7 @@
 				833631CA221B5DFA00BA53EE /* ErrorNotifierSpec.swift */,
 				8354AC75224316C700CDE602 /* Cache */,
 			);
-			path = "Service Objects";
+			path = "ServiceObjects";
 			sourceTree = "<group>";
 		};
 		83396BC71F7C3688000E256E /* Networking */ = {
@@ -885,7 +885,7 @@
 				C443A4092315AA4D00145710 /* NetworkReporter.swift */,
 				831AAE2B20A9E4F600B46DBA /* Throttler.swift */,
 			);
-			path = "Service Objects";
+			path = "ServiceObjects";
 			sourceTree = "<group>";
 		};
 		B467790E24D8AECA00897F00 /* Frameworks */ = {
@@ -1970,7 +1970,7 @@
 			repositoryURL = "https://github.com/LaunchDarkly/swift-eventsource.git";
 			requirement = {
 				kind = upToNextMinorVersion;
-				minimumVersion = 1.1.0;
+				minimumVersion = 1.2.0;
 			};
 		};
 		B4903D9624BD61B200F087C4 /* XCRemoteSwiftPackageReference "OHHTTPStubs" */ = {

LaunchDarkly.xcworkspace/xcshareddata/swiftpm/Package.resolved → LaunchDarkly.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -51,8 +51,8 @@
         "repositoryURL": "https://github.com/LaunchDarkly/swift-eventsource.git",
         "state": {
           "branch": null,
-          "revision": "4f817e1a6ce5f8bc90e06b4f19dcd999db099210",
-          "version": "1.1.0"
+          "revision": "9e224016ec5dfda7d66e0f825152f97cbe44ccb8",
+          "version": "1.2.0"
         }
       }
     ]

LaunchDarkly/LaunchDarkly/Models/DiagnosticEvent.swift

@@ -115,6 +115,7 @@ struct DiagnosticConfig: Codable {
     let maxCachedUsers: Int
     let mobileKeyCount: Int
     let diagnosticRecordingIntervalMillis: Int
+    let customHeaders: Bool
 
     init(config: LDConfig) {
         customBaseURI = config.baseUrl != LDConfig.Defaults.baseUrl
@@ -135,5 +136,6 @@ struct DiagnosticConfig: Codable {
         maxCachedUsers = config.maxCachedUsers >= 0 ? config.maxCachedUsers : -1
         mobileKeyCount = 1 + (config.getSecondaryMobileKeys().count)
         diagnosticRecordingIntervalMillis = Int(round(config.diagnosticRecordingInterval * 1_000))
+        customHeaders = !config.additionalHeaders.isEmpty || config.headerDelegate != nil
     }
 }

LaunchDarkly/LaunchDarkly/Models/LDConfig.swift

@@ -17,6 +17,19 @@ public enum LDStreamingMode {
 
 typealias MobileKey = String
 
+
+/**
+ A callback for dynamically setting http headers when connection & reconnecting to a stream
+ or on every poll request. This function should return a copy of the headers recieved with
+ any modifications or additions needed. Removing headers is discouraged as it may cause 
+ requests to fail.
+
+ - parameter url: The endpoint that is being connected to
+ - parameter headers: The default headers that would be used
+ - returns: The headers that will be used in the request
+ */
+public typealias RequestHeaderTransform = (_ url: URL, _ headers: [String: String]) -> [String: String]
+
 /**
  Use LDConfig to configure the LDClient. When initialized, a LDConfig contains the default values which can be changed as needed.
 
@@ -89,6 +102,9 @@ public struct LDConfig {
 
         /// The default additional headers that should be added to all HTTP requests from SDK components to LaunchDarkly services
         static let additionalHeaders: [String: String] = [:]
+
+        /// a closure to allow dynamic changes of headers on connect & reconnect
+        static let headerDelegate: RequestHeaderTransform? = nil
     }
 
     /// Constants relevant to setting up an `LDConfig`
@@ -238,6 +254,9 @@ public struct LDConfig {
     /// Additional headers that should be added to all HTTP requests from SDK components to LaunchDarkly services
     public var additionalHeaders: [String: String] = [:]
 
+    /// a closure to allow dynamic changes of headers on connect & reconnect
+    public var headerDelegate: RequestHeaderTransform?
+
     /// LaunchDarkly defined minima for selected configurable items
     public let minima: Minima
 

LaunchDarkly/LaunchDarkly/Networking/DarklyService.swift

@@ -80,6 +80,17 @@ final class DarklyService: DarklyServiceProvider {
 
     // MARK: Feature Flags
 
+    private func requestTask(with: URLRequest, 
+                             completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void
+                             ) -> URLSessionDataTask {
+        // copying the request is needed because swift passes by const reference without any real way of changing that
+        var req = with
+        if let headerDelegate = config.headerDelegate {
+            req.allHTTPHeaderFields = headerDelegate(with.url!, req.allHTTPHeaderFields ?? [:])
+        }
+        return self.session.dataTask(with: req, completionHandler: completionHandler)
+    }
+
     func getFeatureFlags(useReport: Bool, completion: ServiceCompletionHandler?) {
         guard !config.mobileKey.isEmpty,
             let flagRequest = flagRequest(useReport: useReport)
@@ -91,7 +102,7 @@ final class DarklyService: DarklyServiceProvider {
             }
             return
         }
-        let dataTask = self.session.dataTask(with: flagRequest) { [weak self] data, response, error in
+        let dataTask = requestTask(with: flagRequest) { [weak self] data, response, error in
             DispatchQueue.main.async {
                 self?.processEtag(from: (data, response, error))
                 completion?((data, response, error))
@@ -166,7 +177,9 @@ final class DarklyService: DarklyServiceProvider {
 
     // MARK: Streaming
 
-    func createEventSource(useReport: Bool, handler: EventHandler, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
+    func createEventSource(useReport: Bool, 
+                           handler: EventHandler, 
+                           errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
         if useReport {
             return serviceFactory.makeStreamingProvider(url: reportStreamRequestUrl,
                                                         httpHeaders: httpHeaders.eventSourceHeaders,
@@ -175,11 +188,13 @@ final class DarklyService: DarklyServiceProvider {
                                                             .dictionaryValue(includePrivateAttributes: true, config: config)
                                                             .jsonData,
                                                         handler: handler,
+                                                        delegate: config.headerDelegate,
                                                         errorHandler: errorHandler)
         }
         return serviceFactory.makeStreamingProvider(url: getStreamRequestUrl,
                                                     httpHeaders: httpHeaders.eventSourceHeaders,
                                                     handler: handler,
+                                                    delegate: config.headerDelegate,
                                                     errorHandler: errorHandler)
     }
 
@@ -206,7 +221,7 @@ final class DarklyService: DarklyServiceProvider {
             }
             return
         }
-        let dataTask = self.session.dataTask(with: eventRequest(eventDictionaries: eventDictionaries, payloadId: payloadId)) { (data, response, error) in
+        let dataTask = requestTask(with: eventRequest(eventDictionaries: eventDictionaries, payloadId: payloadId)) { (data, response, error) in
             completion?((data, response, error))
         }
         dataTask.resume()
@@ -232,7 +247,7 @@ final class DarklyService: DarklyServiceProvider {
             Log.debug(typeName(and: #function, appending: ": ") + "Aborting. No mobile key.")
             return
         }
-        let dataTask = self.session.dataTask(with: diagnosticRequest(diagnosticEvent: diagnosticEvent)) { data, response, error in
+        let dataTask = requestTask(with: diagnosticRequest(diagnosticEvent: diagnosticEvent)) { data, response, error in
             completion?((data, response, error))
         }
         dataTask.resume()
@@ -256,9 +271,7 @@ extension DarklyService: TypeIdentifying { }
 extension URLRequest {
     mutating func appendHeaders(_ newHeaders: [String: String]) {
         var headers = self.allHTTPHeaderFields ?? [:]
-        headers.merge(newHeaders) { _, newValue in
-            newValue
-        }
+        headers.merge(newHeaders) { $1 }
         self.allHTTPHeaderFields = headers
     }
 }

LaunchDarkly/LaunchDarkly/Networking/HTTPHeaders.swift

@@ -100,6 +100,6 @@ struct HTTPHeaders {
     }
 
     private func withAdditionalHeaders(_ headers: [String: String]) -> [String: String] {
-        headers.merging(additionalHeaders, uniquingKeysWith: { $1 })
+        headers.merging(additionalHeaders) { $1 }
     }
 }

LaunchDarkly/LaunchDarkly/Service Objects/ClientServiceFactory.swift → LaunchDarkly/LaunchDarkly/ServiceObjects/ClientServiceFactory.swift

@@ -23,8 +23,8 @@ protocol ClientServiceCreating {
     func makeFlagChangeNotifier() -> FlagChangeNotifying
     func makeEventReporter(config: LDConfig, service: DarklyServiceProvider) -> EventReporting
     func makeEventReporter(config: LDConfig, service: DarklyServiceProvider, onSyncComplete: EventSyncCompleteClosure?) -> EventReporting
-    func makeStreamingProvider(url: URL, httpHeaders: [String: String], handler: EventHandler, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider
-    func makeStreamingProvider(url: URL, httpHeaders: [String: String], connectMethod: String?, connectBody: Data?, handler: EventHandler, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider
+    func makeStreamingProvider(url: URL, httpHeaders: [String: String], handler: EventHandler, delegate: RequestHeaderTransform?, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider
+    func makeStreamingProvider(url: URL, httpHeaders: [String: String], connectMethod: String?, connectBody: Data?, handler: EventHandler, delegate: RequestHeaderTransform?, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider
     func makeEnvironmentReporter() -> EnvironmentReporting
     func makeThrottler(maxDelay: TimeInterval, environmentReporter: EnvironmentReporting) -> Throttling
     func makeErrorNotifier() -> ErrorNotifying
@@ -83,17 +83,29 @@ final class ClientServiceFactory: ClientServiceCreating {
         EventReporter(config: config, service: service, onSyncComplete: onSyncComplete)
     }
 
-    func makeStreamingProvider(url: URL, httpHeaders: [String: String], handler: EventHandler, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
+    func makeStreamingProvider(url: URL, 
+                               httpHeaders: [String: String],
+                               handler: EventHandler,
+                               delegate: RequestHeaderTransform?,
+                               errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
         var config: EventSource.Config = EventSource.Config(handler: handler, url: url)
         config.headers = httpHeaders
+        config.headerTransform = { delegate?(url, $0) ?? $0 }
         if let errorHandler = errorHandler {
             config.connectionErrorHandler = errorHandler
         }
         return EventSource(config: config)
     }
 
-    func makeStreamingProvider(url: URL, httpHeaders: [String: String], connectMethod: String?, connectBody: Data?, handler: EventHandler, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
+    func makeStreamingProvider(url: URL, 
+                               httpHeaders: [String: String], 
+                               connectMethod: String?, 
+                               connectBody: Data?, 
+                               handler: EventHandler, 
+                               delegate: RequestHeaderTransform?,
+                               errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
         var config: EventSource.Config = EventSource.Config(handler: handler, url: url)
+        config.headerTransform = { delegate?(url, $0) ?? $0 }
         config.headers = httpHeaders
         if let errorHandler = errorHandler {
             config.connectionErrorHandler = errorHandler

LaunchDarkly/LaunchDarkly/Service Objects/FlagSynchronizer.swift → LaunchDarkly/LaunchDarkly/ServiceObjects/FlagSynchronizer.swift

@@ -87,7 +87,11 @@ class FlagSynchronizer: LDFlagSynchronizing, EventHandler {
     private var syncQueue = DispatchQueue(label: Constants.queueName, qos: .utility)
     private var eventSourceStarted: Date?
 
-    init(streamingMode: LDStreamingMode, pollingInterval: TimeInterval, useReport: Bool, service: DarklyServiceProvider, onSyncComplete: FlagSyncCompleteClosure?) {
+    init(streamingMode: LDStreamingMode, 
+         pollingInterval: TimeInterval, 
+         useReport: Bool, 
+         service: DarklyServiceProvider,
+         onSyncComplete: FlagSyncCompleteClosure?) {
         Log.debug(FlagSynchronizer.typeName(and: #function) + "streamingMode: \(streamingMode), " + "pollingInterval: \(pollingInterval), " + "useReport: \(useReport)")
         self.streamingMode = streamingMode
         self.pollingInterval = pollingInterval

LaunchDarkly/LaunchDarklyTests/Mocks/ClientServiceMockFactory.swift

@@ -90,16 +90,22 @@ final class ClientServiceMockFactory: ClientServiceCreating {
     }
 
     var makeStreamingProviderCallCount = 0
-    var makeStreamingProviderReceivedArguments: (url: URL, httpHeaders: [String: String], connectMethod: String?, connectBody: Data?, handler: EventHandler, errorHandler: ConnectionErrorHandler?)?
-    func makeStreamingProvider(url: URL, httpHeaders: [String: String], handler: EventHandler, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
+    var makeStreamingProviderReceivedArguments: (url: URL, 
+                                                 httpHeaders: [String: String], 
+                                                 connectMethod: String?, 
+                                                 connectBody: Data?, 
+                                                 handler: EventHandler, 
+                                                 delegate: RequestHeaderTransform?, 
+                                                 errorHandler: ConnectionErrorHandler?)?
+    func makeStreamingProvider(url: URL, httpHeaders: [String: String], handler: EventHandler, delegate: RequestHeaderTransform?, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
         makeStreamingProviderCallCount += 1
-        makeStreamingProviderReceivedArguments = (url, httpHeaders, nil, nil, handler, errorHandler)
+        makeStreamingProviderReceivedArguments = (url, httpHeaders, nil, nil, handler, delegate, errorHandler)
         return DarklyStreamingProviderMock()
     }
 
-    func makeStreamingProvider(url: URL, httpHeaders: [String: String], connectMethod: String?, connectBody: Data?, handler: EventHandler, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
+    func makeStreamingProvider(url: URL, httpHeaders: [String: String], connectMethod: String?, connectBody: Data?, handler: EventHandler, delegate: RequestHeaderTransform?, errorHandler: ConnectionErrorHandler?) -> DarklyStreamingProvider {
         makeStreamingProviderCallCount += 1
-        makeStreamingProviderReceivedArguments = (url, httpHeaders, connectMethod, connectBody, handler, errorHandler)
+        makeStreamingProviderReceivedArguments = (url, httpHeaders, connectMethod, connectBody, handler, delegate, errorHandler)
         return DarklyStreamingProviderMock()
     }
 

LaunchDarkly/LaunchDarklyTests/Models/DiagnosticEventSpec.swift

@@ -238,6 +238,7 @@ final class DiagnosticEventSpec: QuickSpec {
                     expect(diagnosticConfig.maxCachedUsers) == 5
                     expect(diagnosticConfig.mobileKeyCount) == 1
                     expect(diagnosticConfig.diagnosticRecordingIntervalMillis) == 900_000
+                    expect(diagnosticConfig.customHeaders) == false
                 }
             }
             context("init with custom config") {
@@ -261,6 +262,7 @@ final class DiagnosticEventSpec: QuickSpec {
                     expect(diagnosticConfig.maxCachedUsers) == -1
                     expect(diagnosticConfig.mobileKeyCount) == 3
                     expect(diagnosticConfig.diagnosticRecordingIntervalMillis) == 600_000
+                    expect(diagnosticConfig.customHeaders) == false
                 }
             }
             var diagnosticConfig: DiagnosticConfig!
@@ -273,7 +275,7 @@ final class DiagnosticEventSpec: QuickSpec {
                         context("using \(desc) encoding") {
                             it("encodes correct values to keys") {
                                 let decoded = self.loadAndRestoreRaw(scheme, diagnosticConfig)
-                                expect(decoded.count) == 17
+                                expect(decoded.count) == 18
                                 expect((decoded["customBaseURI"] as! Bool)) == diagnosticConfig.customBaseURI
                                 expect((decoded["customEventsURI"] as! Bool)) == diagnosticConfig.customEventsURI
                                 expect((decoded["customStreamURI"] as! Bool)) == diagnosticConfig.customStreamURI

Package.resolved

@@ -51,8 +51,8 @@
         "repositoryURL": "https://github.com/LaunchDarkly/swift-eventsource.git",
         "state": {
           "branch": null,
-          "revision": "4f817e1a6ce5f8bc90e06b4f19dcd999db099210",
-          "version": "1.1.0"
+          "revision": "9e224016ec5dfda7d66e0f825152f97cbe44ccb8",
+          "version": "1.2.0"
         }
       }
     ]

Package.swift

@@ -19,7 +19,7 @@ let package = Package(
         .package(url: "https://github.com/AliSoftware/OHHTTPStubs.git", .upToNextMinor(from: "9.0.0")),
         .package(url: "https://github.com/Quick/Quick.git", .upToNextMinor(from: "3.0.0")),
         .package(url: "https://github.com/Quick/Nimble.git", .upToNextMinor(from: "9.0.0")),
-        .package(url: "https://github.com/LaunchDarkly/swift-eventsource.git", .upToNextMinor(from: "1.1.0"))
+        .package(url: "https://github.com/LaunchDarkly/swift-eventsource.git", .upToNextMinor(from: "1.2.0"))
     ],
     targets: [
         .target(
@@ -32,6 +32,6 @@ let package = Package(
             dependencies: ["LaunchDarkly", "OHHTTPStubsSwift", "Quick", "Nimble"],
             path: "LaunchDarkly",
             exclude: ["LaunchDarklyTests/Info.plist", "LaunchDarklyTests/.swiftlint.yml"],
-            sources: ["GeneratedCode", "LaunchDarklyTests"])
+            sources: ["GeneratedCode", "LaunchDarklyTests"]),
     ],
     swiftLanguageVersions: [.v5])