Add prometheus to alltxt2http

cmd/alltxt2http/main.go

@@ -20,6 +20,7 @@ import (
 //  "github.com/tzneal/ham-go/dxcc"
 //  "github.com/denzs/wsjtx-dashboards/shared/httpstuff"
   "github.com/hpcloud/tail"
+  "github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 var alltxt      string
@@ -55,6 +56,13 @@ func init() {
     FullTimestamp: true,
   }
   log.SetFormatter(formatter)
+
+  log.Info("prometheus exporter enabled..")
+  go func () {
+    server := http.NewServeMux()
+    server.Handle("/metrics", promhttp.Handler())
+    http.ListenAndServe(":9123", server)
+  } ()
 }
 
 func getTimestampFromDb() (int64, bool) {