From 5cff674940924086c543bea81213c6aad25b51ae Mon Sep 17 00:00:00 2001
From: Philipp Mieden <dreadl0ck@protonmail.ch>
Date: Thu, 23 May 2019 17:51:20 +0200
Subject: [PATCH] working on prometheus dashboard

---
 .gitignore                |  1 +
 Makefile                  |  3 +++
 contentserver.go          |  2 +-
 metrics/prometheus.go     | 11 ++++-------
 prometheus/prometheus.yml | 14 ++++++++++++++
 status/metrics.go         | 10 +++++-----
 6 files changed, 28 insertions(+), 13 deletions(-)
 create mode 100644 prometheus/prometheus.yml

diff --git a/.gitignore b/.gitignore
index 8a71575..197a383 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+data
 *.log
 *.test
 cprof-*
diff --git a/Makefile b/Makefile
index 935a186..c667b88 100644
--- a/Makefile
+++ b/Makefile
@@ -58,6 +58,9 @@ run-testserver:
 run-contentserver:
 	contentserver -var-dir var -webserver-address :9191 -address :9999 http://127.0.0.1:1234
 
+run-prometheus:
+	prometheus --config.file=prometheus/prometheus.yml
+
 clean-var:
 	rm var/contentserver-repo-2019*
 
diff --git a/contentserver.go b/contentserver.go
index 55706fe..ee47bcd 100644
--- a/contentserver.go
+++ b/contentserver.go
@@ -26,7 +26,7 @@ const (
 
 	ServiceName                  = "Content Server"
 	DefaultHealthzHandlerAddress = ":8080"
-	DefaultPrometheusListener    = ":9200"
+	DefaultPrometheusListener    = "127.0.0.1:9111"
 )
 
 var (
diff --git a/metrics/prometheus.go b/metrics/prometheus.go
index 919b92a..bcf892c 100644
--- a/metrics/prometheus.go
+++ b/metrics/prometheus.go
@@ -8,17 +8,14 @@ import (
 	"go.uber.org/zap"
 )
 
-func PrometheusHandler() http.Handler {
-	h := http.NewServeMux()
-	h.Handle("/metrics", promhttp.Handler())
-	return h
-}
+const metricsRoute = "/metrics"
 
 func RunPrometheusHandler(listener string) {
 	Log.Info("starting prometheus handler on",
 		zap.String("address", listener),
+		zap.String("route", metricsRoute),
 	)
-	Log.Error("server failed: ",
-		zap.Error(http.ListenAndServe(listener, PrometheusHandler())),
+	Log.Error("prometheus listener failed",
+		zap.Error(http.ListenAndServe(listener, promhttp.Handler())),
 	)
 }
diff --git a/prometheus/prometheus.yml b/prometheus/prometheus.yml
new file mode 100644
index 0000000..f6accda
--- /dev/null
+++ b/prometheus/prometheus.yml
@@ -0,0 +1,14 @@
+# reference: https://prometheus.io/docs/prometheus/latest/configuration/configuration/
+
+global:
+  scrape_interval: 15s
+  scrape_timeout: 15s
+  #evaluation_interval: 15s
+
+scrape_configs:
+  - job_name: contentserver
+    metrics_path: /metrics
+    scheme: http
+    static_configs:
+      - targets:
+        - 127.0.0.1:9111
diff --git a/status/metrics.go b/status/metrics.go
index ed97324..36d69c8 100644
--- a/status/metrics.go
+++ b/status/metrics.go
@@ -63,15 +63,15 @@ func newMetrics() *Metrics {
 			"Duration in seconds for each successful repo.update() call",
 		),
 		ContentRequestCounter: newCounterVec(
-			"num_sockets_total",
-			"Total number of currently open socket connections",
-			metricLabelRemote,
-		),
-		NumSocketsGauge: newGaugeVec(
 			"content_request_count",
 			"Number of requests for content",
 			metricLabelSource,
 		),
+		NumSocketsGauge: newGaugeVec(
+			"num_sockets_total",
+			"Total number of currently open socket connections",
+			metricLabelRemote,
+		),
 	}
 }