From 0f850400f2f954c2f39b7fed79f8782610459268 Mon Sep 17 00:00:00 2001
From: Song Wenhao <wenhao.sng@gmail.com>
Date: Thu, 6 Jul 2017 05:28:44 +0800
Subject: [PATCH] Display error message if prometheus output fails to listen
 (#2984)

---
 plugins/outputs/prometheus_client/prometheus_client.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/plugins/outputs/prometheus_client/prometheus_client.go b/plugins/outputs/prometheus_client/prometheus_client.go
index f16824c9e..f858c6350 100644
--- a/plugins/outputs/prometheus_client/prometheus_client.go
+++ b/plugins/outputs/prometheus_client/prometheus_client.go
@@ -78,7 +78,12 @@ func (p *PrometheusClient) Start() error {
 		Handler: mux,
 	}
 
-	go p.server.ListenAndServe()
+	go func() {
+		if err := p.server.ListenAndServe(); err != nil {
+			log.Printf("E! Error creating prometheus metric endpoint, err: %s\n",
+				err.Error())
+		}
+	}()
 	return nil
 }