From 7c0dd85a7cea242d5e2863b5529c6975090b5522 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Wed, 4 Dec 2019 19:15:49 +0200
Subject: [PATCH] lib/httpserver: add `/ping` handler for compatibility with
 Influx agents

Certain Influx agents check for `/ping` endpoint before starting
to send Influx line protocol data. See https://docs.influxdata.com/influxdb/v1.7/tools/api/#ping-http-endpoint
---
 lib/httpserver/httpserver.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/httpserver/httpserver.go b/lib/httpserver/httpserver.go
index 0c2bec4a3..13fc64aa8 100644
--- a/lib/httpserver/httpserver.go
+++ b/lib/httpserver/httpserver.go
@@ -133,6 +133,15 @@ func handlerWrapper(w http.ResponseWriter, r *http.Request, rh RequestHandler) {
 		w.Header().Set("Content-Type", "text/plain")
 		w.Write([]byte("OK"))
 		return
+	case "/ping":
+		// This is needed for compatibility with Influx agents.
+		// See https://docs.influxdata.com/influxdb/v1.7/tools/api/#ping-http-endpoint
+		status := http.StatusNoContent
+		if verbose := r.FormValue("verbose"); verbose == "true" {
+			status = http.StatusOK
+		}
+		w.WriteHeader(status)
+		return
 	case "/metrics":
 		startTime := time.Now()
 		metricsRequests.Inc()