Add a User-Agent when using the Lambda Runtime API

Author: bmoffatt

Sources/AWSLambdaRuntimeCore/HTTPClient.swift

@@ -26,6 +26,7 @@ internal final class HTTPClient {
 
     private var state = State.disconnected
     private var executing = false
+    private let headers = HTTPHeaders([("User-Agent", "Swift-Lambda/Unknown")])
 
     init(eventLoop: EventLoop, configuration: Lambda.Configuration.RuntimeEngine) {
         self.eventLoop = eventLoop
@@ -37,13 +38,15 @@ internal final class HTTPClient {
         self.execute(Request(targetHost: self.targetHost,
                              url: url,
                              method: .GET,
+                             headers: headers,
                              timeout: timeout ?? self.configuration.requestTimeout))
     }
 
     func post(url: String, body: ByteBuffer?, timeout: TimeAmount? = nil) -> EventLoopFuture<Response> {
         self.execute(Request(targetHost: self.targetHost,
                              url: url,
                              method: .POST,
+                             headers: headers,
                              body: body,
                              timeout: timeout ?? self.configuration.requestTimeout))
     }