Add Prometheus metrics

ihippik · Sep 16, 2022 · d14c499 · d14c499
1 parent bea1a03
commit d14c499
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Showing 6 changed files with 157 additions and 2 deletions.
diff --git a/cmd/wal-listener/init.go b/cmd/wal-listener/init.go
@@ -2,11 +2,13 @@ package main
 
 import (
 	"fmt"
+	"net/http"
 	"runtime/debug"
 
 	"github.com/evalphobia/logrus_sentry"
 	"github.com/jackc/pgx"
 	"github.com/nats-io/nats.go"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/viper"
 
@@ -53,6 +55,18 @@ func getConf(path string) (*config.Config, error) {
 	return &cfg, nil
 }
 
+func initMetrics(logger *logrus.Entry) {
+	const addr = ":2112"
+
+	logger.WithField("addr", addr).Infoln("metrics handler")
+
+	http.Handle("/metrics", promhttp.Handler())
+	if err := http.ListenAndServe(addr, nil); err != nil {
+		logger.WithError(err).Errorln("init metrics handler")
+		return
+	}
+}
+
 // initLogger init logrus preferences.
 func initLogger(cfg config.LoggerCfg, version string) *logrus.Entry {
 	logger := logrus.New()

diff --git a/cmd/wal-listener/main.go b/cmd/wal-listener/main.go
@@ -47,6 +47,8 @@ func main() {
 
 			initSentry(cfg.Monitoring.SentryDSN, logger)
 
+			go initMetrics(logger)
+
 			natsConn, err := nats.Connect(cfg.Nats.Address)
 			if err != nil {
 				return fmt.Errorf("nats connection: %w", err)

diff --git a/go.mod b/go.mod
@@ -11,23 +11,28 @@ require (
 	github.com/jackc/pgx v3.6.2+incompatible
 	github.com/magiconair/properties v1.8.6
 	github.com/nats-io/nats.go v1.16.0
+	github.com/prometheus/client_golang v1.13.0
 	github.com/sirupsen/logrus v1.9.0
 	github.com/spf13/viper v1.12.0
 	github.com/stretchr/testify v1.8.0
 	github.com/urfave/cli/v2 v2.11.1
 )
 
 require (
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/certifi/gocertifi v0.0.0-20210507211836-431795d63e8d // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
 	github.com/cockroachdb/apd v1.1.0 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/fsnotify/fsnotify v1.5.4 // indirect
 	github.com/getsentry/raven-go v0.2.0 // indirect
 	github.com/gofrs/uuid v3.2.0+incompatible // indirect
+	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/jackc/fake v0.0.0-20150926172116-812a484cc733 // indirect
 	github.com/lib/pq v1.2.0 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/nats-io/jwt v1.2.2 // indirect
 	github.com/nats-io/nats-server/v2 v2.1.2 // indirect
@@ -38,6 +43,9 @@ require (
 	github.com/pelletier/go-toml/v2 v2.0.2 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.37.0 // indirect
+	github.com/prometheus/procfs v0.8.0 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/shopspring/decimal v0.0.0-20180709203117-cd690d0c9e24 // indirect
 	github.com/spf13/afero v1.9.2 // indirect
@@ -50,6 +58,7 @@ require (
 	golang.org/x/crypto v0.0.0-20220722155217-630584e8d5aa // indirect
 	golang.org/x/sys v0.0.0-20220804214406-8e32c043e418 // indirect
 	golang.org/x/text v0.3.7 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
 	gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f // indirect
 	gopkg.in/ini.v1 v1.66.6 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect