Add new console/http loggers (#6066)

- Add console target logging, enabled by default.
- Add http target logging, which supports an endpoint
  with basic authentication (username/password are passed
  in the endpoint url itself)
- HTTP target logging is asynchronous and some logs can be
  dropped if channel buffer (10000) is full

cmd/common-main.go

@@ -81,6 +81,20 @@ func initConfig() {
 	}
 }
 
+// Load logger targets based on user's configuration
+func loadLoggers() {
+	if globalServerConfig.Logger.Console.Enabled {
+		// Enable console logging
+		logger.AddTarget(logger.NewConsole())
+	}
+	for _, l := range globalServerConfig.Logger.HTTP {
+		if l.Enabled {
+			// Enable http logging
+			logger.AddTarget(logger.NewHTTP(l.Endpoint, NewCustomHTTPTransport()))
+		}
+	}
+}
+
 func handleCommonCmdArgs(ctx *cli.Context) {
 
 	var configDir string