From d33a447047f2f98eab5c500017da159fd545b9b6 Mon Sep 17 00:00:00 2001
From: Ben Kochie <superq@gmail.com>
Date: Mon, 19 Feb 2018 15:44:59 +0100
Subject: [PATCH] Remove deprecated prometheus.InstrumentHandlerFunc (#831)

Update Prometheus client golang use to use `promhttp.Handler()` instead
of `prometheus.InstrumentHandlerFunc()`.
---
 Makefile                          |  4 +---
 collector/fixtures/e2e-output.txt | 29 ++++++++---------------------
 node_exporter.go                  | 16 +++++++++-------
 3 files changed, 18 insertions(+), 31 deletions(-)

diff --git a/Makefile b/Makefile
index 1bbb136c..32b53637 100644
--- a/Makefile
+++ b/Makefile
@@ -28,9 +28,7 @@ DOCKER_IMAGE_TAG        ?= $(subst /,-,$(shell git rev-parse --abbrev-ref HEAD))
 MACH                    ?= $(shell uname -m)
 DOCKERFILE              ?= Dockerfile
 
-# TODO: Remove deprecated and problematic InstrumentHandlerFunc usage.
-STATICCHECK_IGNORE = \
-  github.com/prometheus/node_exporter/node_exporter.go:SA1019
+STATICCHECK_IGNORE =
 
 ifeq ($(GOHOSTARCH),amd64)
 	# Only supported on amd64
diff --git a/collector/fixtures/e2e-output.txt b/collector/fixtures/e2e-output.txt
index e5a1e130..a7c1e2ac 100644
--- a/collector/fixtures/e2e-output.txt
+++ b/collector/fixtures/e2e-output.txt
@@ -54,27 +54,6 @@
 # TYPE go_memstats_sys_bytes gauge
 # HELP go_threads Number of OS threads created.
 # TYPE go_threads gauge
-# HELP http_request_duration_microseconds The HTTP request latencies in microseconds.
-# TYPE http_request_duration_microseconds summary
-http_request_duration_microseconds{handler="prometheus",quantile="0.5"} NaN
-http_request_duration_microseconds{handler="prometheus",quantile="0.9"} NaN
-http_request_duration_microseconds{handler="prometheus",quantile="0.99"} NaN
-http_request_duration_microseconds_sum{handler="prometheus"} 0
-http_request_duration_microseconds_count{handler="prometheus"} 0
-# HELP http_request_size_bytes The HTTP request sizes in bytes.
-# TYPE http_request_size_bytes summary
-http_request_size_bytes{handler="prometheus",quantile="0.5"} NaN
-http_request_size_bytes{handler="prometheus",quantile="0.9"} NaN
-http_request_size_bytes{handler="prometheus",quantile="0.99"} NaN
-http_request_size_bytes_sum{handler="prometheus"} 0
-http_request_size_bytes_count{handler="prometheus"} 0
-# HELP http_response_size_bytes The HTTP response sizes in bytes.
-# TYPE http_response_size_bytes summary
-http_response_size_bytes{handler="prometheus",quantile="0.5"} NaN
-http_response_size_bytes{handler="prometheus",quantile="0.9"} NaN
-http_response_size_bytes{handler="prometheus",quantile="0.99"} NaN
-http_response_size_bytes_sum{handler="prometheus"} 0
-http_response_size_bytes_count{handler="prometheus"} 0
 # HELP node_arp_entries ARP entries by device
 # TYPE node_arp_entries gauge
 node_arp_entries{device="eth0"} 3
@@ -3722,6 +3701,14 @@ node_zfs_zpool_wupdate{zpool="poolz1"} 1.10734831833266e+14
 # TYPE process_start_time_seconds gauge
 # HELP process_virtual_memory_bytes Virtual memory size in bytes.
 # TYPE process_virtual_memory_bytes gauge
+# HELP promhttp_metric_handler_requests_in_flight Current number of scrapes being served.
+# TYPE promhttp_metric_handler_requests_in_flight gauge
+promhttp_metric_handler_requests_in_flight 1
+# HELP promhttp_metric_handler_requests_total Total number of scrapes by HTTP status code.
+# TYPE promhttp_metric_handler_requests_total counter
+promhttp_metric_handler_requests_total{code="200"} 0
+promhttp_metric_handler_requests_total{code="500"} 0
+promhttp_metric_handler_requests_total{code="503"} 0
 # HELP testmetric1_1 Metric read from collector/fixtures/textfile/two_metric_files/metrics1.prom
 # TYPE testmetric1_1 untyped
 testmetric1_1{foo="bar"} 10
diff --git a/node_exporter.go b/node_exporter.go
index 7c1958ee..b2884c34 100644
--- a/node_exporter.go
+++ b/node_exporter.go
@@ -56,11 +56,14 @@ func handler(w http.ResponseWriter, r *http.Request) {
 		registry,
 	}
 	// Delegate http serving to Prometheus client library, which will call collector.Collect.
-	h := promhttp.HandlerFor(gatherers,
-		promhttp.HandlerOpts{
-			ErrorLog:      log.NewErrorLogger(),
-			ErrorHandling: promhttp.ContinueOnError,
-		})
+	h := promhttp.InstrumentMetricHandler(
+		registry,
+		promhttp.HandlerFor(gatherers,
+			promhttp.HandlerOpts{
+				ErrorLog:      log.NewErrorLogger(),
+				ErrorHandling: promhttp.ContinueOnError,
+			}),
+	)
 	h.ServeHTTP(w, r)
 }
 
@@ -88,8 +91,7 @@ func main() {
 		log.Infof(" - %s", n)
 	}
 
-	// TODO(ts): Remove deprecated and problematic InstrumentHandlerFunc usage.
-	http.HandleFunc(*metricsPath, prometheus.InstrumentHandlerFunc("prometheus", handler))
+	http.HandleFunc(*metricsPath, handler)
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte(`<html>
 			<head><title>Node Exporter</title></head>