From 0140ce11c7f3a2b5792c545a60aa34c90fdefb61 Mon Sep 17 00:00:00 2001
From: Shulhan <ms@kilabit.info>
Date: Fri, 25 Jan 2019 00:43:13 +0700
Subject: haminer: send heartbeat indicator if logs is empty

An administrator may need to monitor if the haminer service is running or
not through kapacitor.  With heartbeat, we can tell if haminer is not
running if no data is send along, say, one hour.
---
 halog.go   | 10 ++++++++++
 haminer.go |  6 ++++++
 2 files changed, 16 insertions(+)

diff --git a/halog.go b/halog.go
index 4bb7b60..555811f 100644
--- a/halog.go
+++ b/halog.go
@@ -11,6 +11,16 @@ import (
 	"time"
 )
 
+// heartbeat of haminer, in case we want to monitor deadman from haminer.
+var heartbeat = &Halog{ // nolint: gochecknoglobals
+	Timestamp:    time.Now(),
+	FrontendName: "-",
+	BackendName:  "-",
+	ServerName:   "-",
+	tagHTTPURL:   "-",
+	HTTPMethod:   "-",
+}
+
 //
 // Halog contains the mapping of haproxy HTTP log format to Go struct.
 //
diff --git a/haminer.go b/haminer.go
index 62a4aa7..d9aa0d7 100644
--- a/haminer.go
+++ b/haminer.go
@@ -137,6 +137,11 @@ func (h *Haminer) consume() {
 }
 
 func (h *Haminer) forwards(halogs []*Halog) {
+	// Send heartbeat indicator, if logs is empty.
+	if len(halogs) == 0 {
+		heartbeat.Timestamp = time.Now()
+		halogs = append(halogs, heartbeat)
+	}
 	for _, fwder := range h.ff {
 		fwder.Forwards(halogs)
 	}
@@ -161,6 +166,7 @@ func (h *Haminer) produce() {
 			halogs = append(halogs, halog)
 		case <-ticker.C:
 			h.forwards(halogs)
+			halogs = nil
 		}
 	}
 }
-- 
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