From 92a3cbaae0d17d134634be6559422598455972c5 Mon Sep 17 00:00:00 2001
From: Knut Ahlers <knut@ahlers.me>
Date: Mon, 2 May 2022 16:10:12 +0200
Subject: [PATCH] Breaking: Remove prometheus support

Signed-off-by: Knut Ahlers <knut@ahlers.me>
---
 main.go    | 21 ++++++---------------
 metrics.go | 50 --------------------------------------------------
 2 files changed, 6 insertions(+), 65 deletions(-)
 delete mode 100644 metrics.go

diff --git a/main.go b/main.go
index e6bf8e5..736f209 100644
--- a/main.go
+++ b/main.go
@@ -14,12 +14,12 @@ import (
 	"sync"
 	"time"
 
-	"github.com/Luzifer/rconfig"
 	"github.com/gorilla/mux"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/robfig/cron"
+	"github.com/robfig/cron/v3"
 	"golang.org/x/net/context"
 	"gopkg.in/yaml.v2"
+
+	"github.com/Luzifer/rconfig/v2"
 )
 
 var (
@@ -126,8 +126,9 @@ func main() {
 
 	r := mux.NewRouter()
 	r.HandleFunc("/status", handleELBHealthCheck)
-	r.Handle("/metrics", prometheus.Handler())
-	http.ListenAndServe(cfg.Listen, r)
+	if err := http.ListenAndServe(cfg.Listen, r); err != nil {
+		log.Fatalf("Unable to listen: %s", err)
+	}
 }
 
 func spawnChecks() {
@@ -140,7 +141,6 @@ func spawnChecks() {
 
 func executeAndRegisterCheck(ctx context.Context, checkID string) {
 	check := checks[checkID]
-	start := time.Now()
 
 	cmd := exec.Command("/bin/bash", "-e", "-o", "pipefail", "-c", check.Command)
 	cmd.Stderr = newPrefixedLogger(os.Stderr, checkID+":STDERR")
@@ -188,13 +188,6 @@ func executeAndRegisterCheck(ctx context.Context, checkID string) {
 
 	lastResultRegistered = time.Now()
 
-	if success {
-		checkPassing.WithLabelValues(checkID).Set(1)
-	} else {
-		checkPassing.WithLabelValues(checkID).Set(0)
-	}
-	checkExecutionTime.WithLabelValues(checkID).Observe(float64(time.Since(start).Nanoseconds()) / float64(time.Microsecond))
-
 	checkResultsLock.Unlock()
 }
 
@@ -224,10 +217,8 @@ func handleELBHealthCheck(res http.ResponseWriter, r *http.Request) {
 	res.Header().Set("X-Collection-Parsed-In", strconv.FormatInt(time.Since(start).Nanoseconds()/int64(time.Microsecond), 10)+"ms")
 	res.Header().Set("X-Last-Result-Registered-At", lastResultRegistered.Format(time.RFC1123))
 	if healthy {
-		currentStatusCode.Set(http.StatusOK)
 		res.WriteHeader(http.StatusOK)
 	} else {
-		currentStatusCode.Set(http.StatusInternalServerError)
 		res.WriteHeader(http.StatusInternalServerError)
 	}
 
diff --git a/metrics.go b/metrics.go
deleted file mode 100644
index 7059664..0000000
--- a/metrics.go
+++ /dev/null
@@ -1,50 +0,0 @@
-package main
-
-import (
-	"log"
-	"os"
-
-	"github.com/prometheus/client_golang/prometheus"
-)
-
-var (
-	checkPassing       *prometheus.GaugeVec
-	checkExecutionTime *prometheus.SummaryVec
-	currentStatusCode  prometheus.Gauge
-
-	dynamicLabels = []string{"check_id"}
-)
-
-func init() {
-	hostname, err := os.Hostname()
-	if err != nil {
-		log.Fatalf("Unable to determine own hostname: %s", err)
-	}
-
-	co := prometheus.GaugeOpts{
-		Subsystem:   "elb_instance_status",
-		ConstLabels: prometheus.Labels{"hostname": hostname},
-	}
-
-	co.Name = "check_passing"
-	co.Help = "Bit showing whether the check PASSed (=1) or FAILed (=0), WARNs are also reported as FAILs"
-
-	cp := prometheus.NewGaugeVec(co, dynamicLabels)
-
-	co.Name = "status_code"
-	co.Help = "Contains the current HTTP status code the ELB is seeing"
-
-	csc := prometheus.NewGauge(co)
-
-	cet := prometheus.NewSummaryVec(prometheus.SummaryOpts{
-		Namespace:   co.Namespace,
-		Subsystem:   co.Subsystem,
-		ConstLabels: co.ConstLabels,
-		Name:        "check_execution_time",
-		Help:        "Timespan in µs the execution of the check took",
-	}, dynamicLabels)
-
-	checkPassing = prometheus.MustRegisterOrGet(cp).(*prometheus.GaugeVec)
-	currentStatusCode = prometheus.MustRegisterOrGet(csc).(prometheus.Gauge)
-	checkExecutionTime = prometheus.MustRegisterOrGet(cet).(*prometheus.SummaryVec)
-}