added initial exporter metric code (#637)

Sources/Exporters/OpenTelemetryProtocolCommon/common/ExporterMetrics.swift

@@ -0,0 +1,97 @@
+//
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+// 
+import Foundation
+import OpenTelemetryApi
+
+/// `ExporterMetrics` will provide a way to track how many data have been seen or successfully exported,
+/// as well as how many failed. The exporter will adopt an instance of this and inject the provider as a dependency.
+/// The host application can then track different types of exporters, such as `http, grpc, and log`
+public class ExporterMetrics {
+    public enum TransporterType: String {
+        case grpc = "grpc"
+        case protoBuf = "http"
+        case httpJson = "http-json"
+    }
+
+    public static let ATTRIBUTE_KEY_TYPE: String = "type"
+    public static let ATTRIBUTE_KEY_SUCCESS: String = "success"
+
+    private let meterProvider: StableMeterProvider
+    private let exporterName: String
+    private let transportName: String
+    private var seenAttrs: [String: AttributeValue] = [:]
+    private var successAttrs: [String: AttributeValue] = [:]
+    private var failedAttrs: [String: AttributeValue] = [:]
+
+    private var seen: LongCounter?
+    private var exported: LongCounter?
+
+    /// - Parameters:
+    ///    - type: That represent what type of exporter it is. `otlp`
+    ///    - meterProvider: Injected `StableMeterProvider` for metric
+    ///    - exporterName: Could be `span`, `log` etc
+    ///    - transportName: Kind of exporter defined by type `TransporterType`
+    public init(
+        type: String,
+        meterProvider: StableMeterProvider,
+        exporterName: String,
+        transportName: TransporterType
+    ) {
+        self.meterProvider = meterProvider
+        self.exporterName = exporterName
+        self.transportName = transportName.rawValue
+        self.seenAttrs = [
+            ExporterMetrics.ATTRIBUTE_KEY_TYPE: .string(type)
+        ]
+        self.successAttrs = [
+            ExporterMetrics.ATTRIBUTE_KEY_SUCCESS: .bool(true)
+        ]
+        self.failedAttrs = [
+            ExporterMetrics.ATTRIBUTE_KEY_SUCCESS: .bool(false)
+        ]
+
+        self.seen = meter.counterBuilder(name: "\(exporterName).exporter.seen").build()
+        self.exported = meter.counterBuilder(name: "\(exporterName).exporter.exported").build()
+
+    }
+
+    public func addSeen(value: Int) -> Void {
+        seen?.add(value: value, attribute: seenAttrs)
+    }
+
+    public func addSuccess(value: Int) -> Void {
+        exported?.add(value: value, attribute: successAttrs)
+    }
+
+    public func addFailed(value: Int) -> Void {
+        exported?.add(value: value, attribute: failedAttrs)
+    }
+
+    // MARK: - Private functions
+
+    /***
+     * Create an instance for recording exporter metrics under the meter
+     * "io.opentelemetry.exporters." + exporterName + "-transporterType".
+     **/
+    private var meter: StableMeter {
+        meterProvider.get(name: "io.opentelemetry.exporters.\(exporterName)-\(transportName)")
+    }
+
+    // MARK: - Static function
+
+    public static func makeExporterMetric(
+        type: String,
+        meterProvider: StableMeterProvider,
+        exporterName: String,
+        transportName: TransporterType
+    ) -> ExporterMetrics {
+        ExporterMetrics(
+            type: type,
+            meterProvider: meterProvider,
+            exporterName: exporterName,
+            transportName: transportName
+        )
+    }
+}

Sources/Exporters/OpenTelemetryProtocolCommon/common/OtlpConfiguration.swift

@@ -30,14 +30,16 @@ public struct OtlpConfiguration {
     public let headers : [(String,String)]?
     public let timeout : TimeInterval
     public let compression: CompressionType
-
+    public let exportAsJson: Bool
     public init(
         timeout : TimeInterval  = OtlpConfiguration.DefaultTimeoutInterval,
         compression: CompressionType = .gzip,
-        headers: [(String,String)]? = nil
+        headers: [(String,String)]? = nil,
+        exportAsJson: Bool = true
     ) {
         self.headers = headers
         self.timeout = timeout
         self.compression = compression
+        self.exportAsJson = exportAsJson
     }
 }

Sources/Exporters/OpenTelemetryProtocolHttp/OtlpHttpExporterBase.swift

@@ -14,21 +14,25 @@ import FoundationNetworking
 #endif
 
 public class OtlpHttpExporterBase {
-  let endpoint: URL
-  let httpClient: HTTPClient
-  let envVarHeaders : [(String,String)]?
-
-  let config : OtlpConfiguration
-  public init(endpoint: URL, config: OtlpConfiguration = OtlpConfiguration(), useSession: URLSession? = nil, envVarHeaders: [(String,String)]? = EnvVarHeaders.attributes) {
-    self.envVarHeaders = envVarHeaders
-
-    self.endpoint = endpoint
-    self.config = config
-    if let providedSession = useSession {
-      self.httpClient = HTTPClient(session: providedSession)
-    } else {
-      self.httpClient = HTTPClient()
-    }
+    let endpoint: URL
+    let httpClient: HTTPClient
+    let envVarHeaders : [(String,String)]?
+    let config : OtlpConfiguration
+
+  public init(
+    endpoint: URL,
+    config: OtlpConfiguration = OtlpConfiguration(),
+    useSession: URLSession? = nil,
+    envVarHeaders: [(String,String)]? = EnvVarHeaders.attributes
+  ) {
+      self.envVarHeaders = envVarHeaders
+      self.endpoint = endpoint
+      self.config = config
+      if let providedSession = useSession {
+          self.httpClient = HTTPClient(session: providedSession)
+      } else {
+          self.httpClient = HTTPClient()
+      }
   }
 
     public func createRequest(body: Message, endpoint: URL) -> URLRequest {

Sources/Exporters/OpenTelemetryProtocolHttp/logs/OtlpHttpLogExporter.swift

@@ -6,6 +6,7 @@
 import Foundation
 import OpenTelemetryProtocolExporterCommon
 import OpenTelemetrySdk
+import OpenTelemetryApi
 #if canImport(FoundationNetworking)
 import FoundationNetworking
 #endif
@@ -17,13 +18,47 @@ public func defaultOltpHttpLoggingEndpoint() -> URL {
 public class OtlpHttpLogExporter: OtlpHttpExporterBase, LogRecordExporter {
     var pendingLogRecords: [ReadableLogRecord] = []
     private let exporterLock = Lock()
-    override public init(endpoint: URL = defaultOltpHttpLoggingEndpoint(),
-                         config: OtlpConfiguration = OtlpConfiguration(),
-                         useSession: URLSession? = nil,
-                         envVarHeaders: [(String, String)]? = EnvVarHeaders.attributes) {
-        super.init(endpoint: endpoint, config: config, useSession: useSession, envVarHeaders: envVarHeaders)
+    private var exporterMetrics: ExporterMetrics?
+
+    override public init(
+        endpoint: URL = defaultOltpHttpLoggingEndpoint(),
+        config: OtlpConfiguration = OtlpConfiguration(),
+        useSession: URLSession? = nil,
+        envVarHeaders: [(String, String)]? = EnvVarHeaders.attributes
+    ) {
+        super.init(
+            endpoint: endpoint,
+            config: config,
+            useSession: useSession,
+            envVarHeaders: envVarHeaders
+        )
     }
 
+    /// A `convenience` constructor to provide support for exporter metric using`StableMeterProvider` type
+    /// - Parameters:
+    ///    - endpoint: Exporter endpoint injected as dependency
+    ///    - config: Exporter configuration including type of exporter
+    ///    - meterProvider: Injected `StableMeterProvider` for metric
+    ///    - useSession: Overridden `URLSession` if any
+    ///    - envVarHeaders: Extra header key-values
+    convenience public init(
+        endpoint: URL = defaultOltpHttpLoggingEndpoint(),
+        config: OtlpConfiguration = OtlpConfiguration(),
+        meterProvider: StableMeterProvider,
+        useSession: URLSession? = nil,
+        envVarHeaders: [(String, String)]? = EnvVarHeaders.attributes
+    ) {
+        self.init(endpoint: endpoint, config: config, useSession: useSession, envVarHeaders: envVarHeaders)
+        exporterMetrics = ExporterMetrics(
+            type: "otlp",
+            meterProvider: meterProvider,
+            exporterName: "log",
+            transportName: config.exportAsJson ?
+                ExporterMetrics.TransporterType.httpJson :
+                ExporterMetrics.TransporterType.grpc
+        )
+    }
+
     public func export(logRecords: [OpenTelemetrySdk.ReadableLogRecord], explicitTimeout: TimeInterval? = nil) -> OpenTelemetrySdk.ExportResult {
         var sendingLogRecords: [ReadableLogRecord] = []
         exporterLock.withLockVoid {
@@ -47,12 +82,15 @@ public class OtlpHttpLogExporter: OtlpHttpExporterBase, LogRecordExporter {
                 request.addValue(value, forHTTPHeaderField: key)
             }
         }
+        exporterMetrics?.addSeen(value: sendingLogRecords.count)
         request.timeoutInterval = min(explicitTimeout ?? TimeInterval.greatestFiniteMagnitude, config.timeout)
         httpClient.send(request: request) { [weak self] result in
             switch result {
             case .success:
+                self?.exporterMetrics?.addSuccess(value: sendingLogRecords.count)
                 break
             case let .failure(error):
+                self?.exporterMetrics?.addFailed(value: sendingLogRecords.count)
                 self?.exporterLock.withLockVoid {
                     self?.pendingLogRecords.append(contentsOf: sendingLogRecords)
                 }
@@ -90,11 +128,13 @@ public class OtlpHttpLogExporter: OtlpHttpExporterBase, LogRecordExporter {
                     request.addValue(value, forHTTPHeaderField: key)
                 }
             }
-            httpClient.send(request: request) { result in
+            httpClient.send(request: request) { [weak self] result in
                 switch result {
                 case .success:
+                    self?.exporterMetrics?.addSuccess(value: pendingLogRecords.count)
                     exporterResult = ExportResult.success
                 case let .failure(error):
+                    self?.exporterMetrics?.addFailed(value: pendingLogRecords.count)
                     print(error)
                     exporterResult = ExportResult.failure
                 }

Sources/Exporters/OpenTelemetryProtocolHttp/metric/OltpHTTPMetricExporter.swift

@@ -6,6 +6,7 @@
 import OpenTelemetrySdk
 import OpenTelemetryProtocolExporterCommon
 import Foundation
+import OpenTelemetryApi
 #if canImport(FoundationNetworking)
 import FoundationNetworking
 #endif
@@ -16,14 +17,50 @@ public func defaultOltpHTTPMetricsEndpoint() -> URL {
 
 @available(*, deprecated, renamed: "StableOtlpHTTPMetricExporter")
 public class OtlpHttpMetricExporter: OtlpHttpExporterBase, MetricExporter {
-  var pendingMetrics: [Metric] = []
-  private let exporterLock = Lock()
-
+    var pendingMetrics: [Metric] = []
+    private let exporterLock = Lock()
+    private var exporterMetrics: ExporterMetrics?
+
   override
-  public init(endpoint: URL = defaultOltpHTTPMetricsEndpoint(), config : OtlpConfiguration = OtlpConfiguration(), useSession: URLSession? = nil, envVarHeaders: [(String,String)]? = EnvVarHeaders.attributes) {
-    super.init(endpoint: endpoint, config: config, useSession: useSession, envVarHeaders: envVarHeaders)
+  public init(
+    endpoint: URL = defaultOltpHTTPMetricsEndpoint(),
+    config : OtlpConfiguration = OtlpConfiguration(),
+    useSession: URLSession? = nil,
+    envVarHeaders: [(String,String)]? = EnvVarHeaders.attributes
+  ) {
+      super.init(
+        endpoint: endpoint,
+        config: config,
+        useSession: useSession,
+        envVarHeaders: envVarHeaders
+      )
   }
-
+
+    /// A `convenience` constructor to provide support for exporter metric using`StableMeterProvider` type
+    /// - Parameters:
+    ///    - endpoint: Exporter endpoint injected as dependency
+    ///    - config: Exporter configuration including type of exporter
+    ///    - meterProvider: Injected `StableMeterProvider` for metric
+    ///    - useSession: Overridden `URLSession` if any
+    ///    - envVarHeaders: Extra header key-values
+    convenience public init(
+        endpoint: URL = defaultOltpHTTPMetricsEndpoint(),
+        config : OtlpConfiguration = OtlpConfiguration(),
+        meterProvider: StableMeterProvider,
+        useSession: URLSession? = nil,
+        envVarHeaders: [(String,String)]? = EnvVarHeaders.attributes
+    ) {
+        self.init(endpoint: endpoint, config: config, useSession: useSession, envVarHeaders: envVarHeaders)
+        exporterMetrics = ExporterMetrics(
+            type: "otlp",
+            meterProvider: meterProvider,
+            exporterName: "metric",
+            transportName: config.exportAsJson ?
+                ExporterMetrics.TransporterType.httpJson :
+                ExporterMetrics.TransporterType.grpc
+        )
+    }
+
   public func export(metrics: [Metric], shouldCancel: (() -> Bool)?) -> MetricExporterResultCode {
     var sendingMetrics: [Metric] = []
     exporterLock.withLockVoid {
@@ -46,11 +83,14 @@ public class OtlpHttpMetricExporter: OtlpHttpExporterBase, MetricExporter {
             request.addValue(value, forHTTPHeaderField: key)
         }
     }
+      exporterMetrics?.addSeen(value: sendingMetrics.count)
     httpClient.send(request: request) { [weak self] result in
       switch result {
       case .success(_):
+          self?.exporterMetrics?.addSuccess(value: sendingMetrics.count)
         break
       case .failure(let error):
+          self?.exporterMetrics?.addFailed(value: sendingMetrics.count)
         self?.exporterLock.withLockVoid {
           self?.pendingMetrics.append(contentsOf: sendingMetrics)
         }
@@ -64,25 +104,27 @@ public class OtlpHttpMetricExporter: OtlpHttpExporterBase, MetricExporter {
   public func flush() -> MetricExporterResultCode {
     var exporterResult: MetricExporterResultCode = .success
 
-    if !pendingMetrics.isEmpty {
-      let body = Opentelemetry_Proto_Collector_Metrics_V1_ExportMetricsServiceRequest.with {
-        $0.resourceMetrics = MetricsAdapter.toProtoResourceMetrics(metricDataList: pendingMetrics)
+      if !pendingMetrics.isEmpty {
+          let body = Opentelemetry_Proto_Collector_Metrics_V1_ExportMetricsServiceRequest.with {
+              $0.resourceMetrics = MetricsAdapter.toProtoResourceMetrics(metricDataList: pendingMetrics)
+          }
+
+          let semaphore = DispatchSemaphore(value: 0)
+          let request = createRequest(body: body, endpoint: endpoint)
+          httpClient.send(request: request) { [weak self, count = pendingMetrics.count] result in
+              switch result {
+              case .success(_):
+                  self?.exporterMetrics?.addSuccess(value: count)
+                  break
+              case .failure(let error):
+                  self?.exporterMetrics?.addFailed(value: count)
+                  print(error)
+                  exporterResult = MetricExporterResultCode.failureNotRetryable
+              }
+              semaphore.signal()
+          }
+          semaphore.wait()
       }
-
-      let semaphore = DispatchSemaphore(value: 0)
-      let request = createRequest(body: body, endpoint: endpoint)
-      httpClient.send(request: request) { result in
-        switch result {
-        case .success(_):
-          break
-        case .failure(let error):
-          print(error)
-          exporterResult = MetricExporterResultCode.failureNotRetryable
-        }
-        semaphore.signal()
-      }
-      semaphore.wait()
-    }
-    return exporterResult
+      return exporterResult
   }
 }