feat: replace prometheus metric library (#439)

- https://github.com/prometheus/client_golang provides better support
for autogenerating dashboard with the provided metrics

Signed-off-by: Kush Sharma <[email protected]>

README.md

@@ -84,7 +84,7 @@ docker pull raystack/frontier:latest
 To pull a specific version:
 
 ```
-docker pull raystack/frontier:0.8.1
+docker pull raystack/frontier:0.8.8
 ```
 
 ## Usage

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/google/uuid v1.4.0
 	github.com/gorilla/securecookie v1.1.1
 	github.com/grpc-ecosystem/go-grpc-middleware v1.4.0
+	github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.0
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.18.0
 	github.com/jackc/pgconn v1.13.0
 	github.com/jackc/pgerrcode v0.0.0-20220416144525-469b46aa5efa
@@ -37,10 +38,6 @@ require (
 	github.com/stretchr/testify v1.8.4
 	github.com/stripe/stripe-go/v75 v75.10.0
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.46.0
-	go.opentelemetry.io/contrib/instrumentation/runtime v0.46.1
-	go.opentelemetry.io/otel v1.21.0
-	go.opentelemetry.io/otel/exporters/prometheus v0.44.0
-	go.opentelemetry.io/otel/sdk/metric v1.21.0
 	go.uber.org/zap v1.25.0
 	gocloud.dev v0.28.0
 	golang.org/x/oauth2 v0.13.0
@@ -80,8 +77,8 @@ require (
 	github.com/spf13/afero v1.10.0 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
 	go.opencensus.io v0.24.0 // indirect
+	go.opentelemetry.io/otel v1.21.0 // indirect
 	go.opentelemetry.io/otel/metric v1.21.0 // indirect
-	go.opentelemetry.io/otel/sdk v1.21.0 // indirect
 	go.opentelemetry.io/otel/trace v1.21.0 // indirect
 	golang.org/x/mod v0.13.0 // indirect
 	golang.org/x/net v0.17.0 // indirect

go.sum

@@ -1376,6 +1376,8 @@ github.com/grpc-ecosystem/go-grpc-middleware v1.0.1-0.20190118093823-f849b5445de
 github.com/grpc-ecosystem/go-grpc-middleware v1.3.0/go.mod h1:z0ButlSOZa5vEBq9m2m2hlwIgKw+rp3sdCBRoJY+30Y=
 github.com/grpc-ecosystem/go-grpc-middleware v1.4.0 h1:UH//fgunKIs4JdUbpDl1VZCDaL56wXCB/5+wF6uHfaI=
 github.com/grpc-ecosystem/go-grpc-middleware v1.4.0/go.mod h1:g5qyo/la0ALbONm6Vbp88Yd8NsDy6rZz+RcrMPxvld8=
+github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.0 h1:f4tggROQKKcnh4eItay6z/HbHLqghBxS8g7pyMhmDio=
+github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus v1.0.0/go.mod h1:hKAkSgNkL0FII46ZkJcpVEAai4KV+swlIWCKfekd1pA=
 github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.0.1 h1:HcUWd006luQPljE73d5sk+/VgYPGUReEVz2y1/qylwY=
 github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.0.1/go.mod h1:w9Y7gY31krpLmrVU5ZPG9H7l9fZuRu5/3R3S3FMtVQ4=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
@@ -2282,8 +2284,6 @@ go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.4
 go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.20.0/go.mod h1:2AboqHi0CiIZU0qwhtUfCYD1GeUzvvIXWNkhDt7ZMG4=
 go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.31.0/go.mod h1:PFmBsWbldL1kiWZk9+0LBZz2brhByaGsvp6pRICMlPE=
 go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.36.4/go.mod h1:l2MdsbKTocpPS5nQZscqTR9jd8u96VYZdcpF8Sye7mA=
-go.opentelemetry.io/contrib/instrumentation/runtime v0.46.1 h1:m9ReioVPIffxjJlGNRd0d5poy+9oTro3D+YbiEzUDOc=
-go.opentelemetry.io/contrib/instrumentation/runtime v0.46.1/go.mod h1:CANkrsXNzqOKXfOomu2zhOmc1/J5UZK9SGjrat6ZCG0=
 go.opentelemetry.io/otel v0.20.0/go.mod h1:Y3ugLH2oa81t5QO+Lty+zXf8zC9L26ax4Nzoxm/dooo=
 go.opentelemetry.io/otel v1.3.0/go.mod h1:PWIKzi6JCp7sM0k9yZ43VX+T345uNbAkDKwHVjb2PTs=
 go.opentelemetry.io/otel v1.6.0/go.mod h1:bfJD2DZVw0LBxghOTlgnlI0CV3hLDu9XF/QKOUXMTQQ=
@@ -2304,8 +2304,6 @@ go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.11.1/go.mod h
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.3.0/go.mod h1:QNX1aly8ehqqX1LEa6YniTU7VY9I6R3X/oPxhGdTceE=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.6.1/go.mod h1:DAKwdo06hFLc0U88O10x4xnb5sc7dDRDqRuiN+io8JE=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.11.1/go.mod h1:X620Jww3RajCJXw/unA+8IRTgxkdS7pi+ZwK9b7KUJk=
-go.opentelemetry.io/otel/exporters/prometheus v0.44.0 h1:08qeJgaPC0YEBu2PQMbqU3rogTlyzpjhCI2b58Yn00w=
-go.opentelemetry.io/otel/exporters/prometheus v0.44.0/go.mod h1:ERL2uIeBtg4TxZdojHUwzZfIFlUIjZtxubT5p4h1Gjg=
 go.opentelemetry.io/otel/metric v0.20.0/go.mod h1:598I5tYlH1vzBjn+BTuhzTCSb/9debfNp6R3s7Pr1eU=
 go.opentelemetry.io/otel/metric v0.28.0/go.mod h1:TrzsfQAmQaB1PDcdhBauLMk7nyyg9hm+GoQq/ekE9Iw=
 go.opentelemetry.io/otel/metric v0.33.0/go.mod h1:QlTYc+EnYNq/M2mNk1qDDMRLpqCOj2f/r5c7Fd5FYaI=
@@ -2316,12 +2314,8 @@ go.opentelemetry.io/otel/sdk v0.20.0/go.mod h1:g/IcepuwNsoiX5Byy2nNV0ySUF1em498m
 go.opentelemetry.io/otel/sdk v1.3.0/go.mod h1:rIo4suHNhQwBIPg9axF8V9CA72Wz2mKF1teNrup8yzs=
 go.opentelemetry.io/otel/sdk v1.6.1/go.mod h1:IVYrddmFZ+eJqu2k38qD3WezFR2pymCzm8tdxyh3R4E=
 go.opentelemetry.io/otel/sdk v1.11.1/go.mod h1:/l3FE4SupHJ12TduVjUkZtlfFqDCQJlOlithYrdktys=
-go.opentelemetry.io/otel/sdk v1.21.0 h1:FTt8qirL1EysG6sTQRZ5TokkU8d0ugCj8htOgThZXQ8=
-go.opentelemetry.io/otel/sdk v1.21.0/go.mod h1:Nna6Yv7PWTdgJHVRD9hIYywQBRx7pbox6nwBnZIxl/E=
 go.opentelemetry.io/otel/sdk/export/metric v0.20.0/go.mod h1:h7RBNMsDJ5pmI1zExLi+bJK+Dr8NQCh0qGhm1KDnNlE=
 go.opentelemetry.io/otel/sdk/metric v0.20.0/go.mod h1:knxiS8Xd4E/N+ZqKmUPf3gTTZ4/0TjTXukfxjzSTpHE=
-go.opentelemetry.io/otel/sdk/metric v1.21.0 h1:smhI5oD714d6jHE6Tie36fPx4WDFIg+Y6RfAY4ICcR0=
-go.opentelemetry.io/otel/sdk/metric v1.21.0/go.mod h1:FJ8RAsoPGv/wYMgBdUJXOm+6pzFY3YdljnXtv1SBE8Q=
 go.opentelemetry.io/otel/trace v0.20.0/go.mod h1:6GjCW8zgDjwGHGa6GkyeB8+/5vjT16gUEi0Nf1iBdgw=
 go.opentelemetry.io/otel/trace v1.3.0/go.mod h1:c/VDhno8888bvQYmbYLqe41/Ldmr/KKunbvWM4/fEjk=
 go.opentelemetry.io/otel/trace v1.6.0/go.mod h1:qs7BrU5cZ8dXQHBGxHMOxwME/27YH2qEp4/+tZLLwJE=

main.go

@@ -3,16 +3,10 @@ package main
 import (
 	"fmt"
 	"os"
-	"time"
-
-	"go.opentelemetry.io/otel"
-	"go.opentelemetry.io/otel/sdk/metric"
 
 	"github.com/raystack/frontier/cmd"
 
 	_ "github.com/authzed/authzed-go/proto/authzed/api/v0"
-	"go.opentelemetry.io/contrib/instrumentation/runtime"
-	"go.opentelemetry.io/otel/exporters/prometheus"
 )
 
 func main() {
@@ -21,23 +15,6 @@ func main() {
 		cliConfig = &cmd.Config{}
 	}
 
-	// The exporter embeds a default OpenTelemetry Reader and
-	// implements prometheus.Collector, allowing it to be used as
-	// both a Reader and Collector.
-	exporter, err := prometheus.New()
-	if err != nil {
-		fmt.Printf("%+v\n", err)
-		os.Exit(1)
-	}
-	provider := metric.NewMeterProvider(metric.WithReader(exporter))
-	otel.SetMeterProvider(provider)
-
-	err = runtime.Start(runtime.WithMinimumReadMemStatsInterval(time.Second * 5))
-	if err != nil {
-		fmt.Printf("%+v\n", err)
-		os.Exit(1)
-	}
-
 	if err := cmd.New(cliConfig).Execute(); err != nil {
 		fmt.Printf("%+v\n", err)
 		os.Exit(1)

pkg/server/server.go

@@ -8,6 +8,9 @@ import (
 	"strings"
 	"time"
 
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
+
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
 
@@ -24,6 +27,7 @@ import (
 	"github.com/gorilla/securecookie"
 	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
 	grpc_zap "github.com/grpc-ecosystem/go-grpc-middleware/logging/zap"
+	grpcprom "github.com/grpc-ecosystem/go-grpc-middleware/providers/prometheus"
 	grpc_recovery "github.com/grpc-ecosystem/go-grpc-middleware/recovery"
 	grpc_ctxtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
 	grpc_validator "github.com/grpc-ecosystem/go-grpc-middleware/validator"
@@ -157,8 +161,23 @@ func Serve(
 
 	v1beta1.Register(grpcServer, deps, cfg.Authentication)
 
+	// setup metrics
+	srvMetrics := grpcprom.NewServerMetrics(
+		grpcprom.WithServerHandlingTimeHistogram(
+			grpcprom.WithHistogramBuckets([]float64{0.001, 0.01, 0.1, 0.3, 0.6, 1, 3, 6, 9, 20, 30, 60, 90, 120}),
+		),
+	)
+	promRegistry := prometheus.NewRegistry()
+	promRegistry.MustRegister(
+		srvMetrics,
+		collectors.NewGoCollector(),
+		collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}),
+	)
+	srvMetrics.InitializeMetrics(grpcServer)
 	httpMuxMetrics := http.NewServeMux()
-	httpMuxMetrics.Handle("/metrics", promhttp.Handler())
+	httpMuxMetrics.Handle("/metrics", promhttp.HandlerFor(promRegistry, promhttp.HandlerOpts{
+		EnableOpenMetrics: true,
+	}))
 
 	logger.Info("api server starting", "http-port", cfg.Port, "grpc-port", cfg.GRPC.Port, "metrics-port", cfg.MetricsPort)
 	if err := mux.Serve(