Prometheus, redone middleware

.gitignore

@@ -21,3 +21,6 @@
 
 # Data generated by Prometheus (I think?)
 data/
+
+# MacOS
+.DS_Store

cmd/main.go

@@ -5,11 +5,11 @@ import (
 
 	"github.com/gilperopiola/go-rest-example/pkg/common/auth"
 	"github.com/gilperopiola/go-rest-example/pkg/common/config"
-	"github.com/gilperopiola/go-rest-example/pkg/common/metrics"
 	"github.com/gilperopiola/go-rest-example/pkg/common/middleware"
 	"github.com/gilperopiola/go-rest-example/pkg/repository"
 	"github.com/gilperopiola/go-rest-example/pkg/service"
 	"github.com/gilperopiola/go-rest-example/pkg/transport"
+	"github.com/gin-gonic/gin"
 )
 
 // TODO
@@ -34,17 +34,23 @@ func main() {
 		// Load configuration settings
 		config = config.New(".env")
 
-		// Init Prometheus metrics
-		metrics = metrics.New()
-
 		// Initialize logger
 		logger = middleware.NewLogger()
 
-		// Initialize middlewares: logger, monitoring, prometheus
-		middlewares = middleware.Middlewares{
-			LoggerToCtx: middleware.NewLoggerToContextMiddleware(logger),
-			Monitoring:  middleware.NewMonitoringMiddleware(config.Monitoring),
-			Prometheus:  middleware.NewPrometheusMiddleware(metrics),
+		// We use prometheus to get metrics
+		prometheus = middleware.NewPrometheus(logger)
+
+		// We use New Relic to monitor the app
+		newRelic = middleware.NewMonitoringNewRelic(config.Monitoring)
+
+		// Initialize middlewares
+		middlewares = []gin.HandlerFunc{
+			gin.Recovery(),
+			middleware.NewCORSConfigMiddleware(),
+			middleware.NewLoggerToContextMiddleware(logger),
+			middleware.NewNewRelicMiddleware(newRelic),
+			middleware.NewPrometheusMiddleware(prometheus),
+			middleware.NewTimeoutMiddleware(config.General.Timeout),
 		}
 
 		// Initialize authentication module
@@ -56,10 +62,10 @@ func main() {
 		// Initialize repository layer with the database connection
 		repository = repository.New(database)
 
-		// Setup the main service layer with dependencies
+		// Setup the main service layer
 		service = service.New(repository, auth, config)
 
-		// Setup endpoints & transport layer with dependencies
+		// Setup endpoints & transport layer
 		endpoints = transport.New(service, transport.NewErrorsMapper(logger))
 
 		// Initialize the router with the endpoints

go.mod

@@ -13,6 +13,7 @@ require (
 	github.com/kelseyhightower/envconfig v1.4.0
 	github.com/newrelic/go-agent/v3 v3.26.0
 	github.com/newrelic/go-agent/v3/integrations/nrgin v1.2.1
+	github.com/prometheus/client_golang v1.17.0
 	github.com/sirupsen/logrus v1.9.3
 	github.com/stretchr/testify v1.8.4
 )
@@ -36,15 +37,13 @@ require (
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/compress v1.17.0 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.5 // indirect
-	github.com/kr/pretty v0.3.1 // indirect
 	github.com/leodido/go-urn v1.2.4 // indirect
 	github.com/mattn/go-isatty v0.0.19 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pelletier/go-toml/v2 v2.1.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/prometheus/client_golang v1.17.0 // indirect
 	github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16 // indirect
 	github.com/prometheus/common v0.44.0 // indirect
 	github.com/prometheus/procfs v0.11.1 // indirect

go.sum

@@ -91,7 +91,6 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
-github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
@@ -136,8 +135,7 @@ github.com/prometheus/procfs v0.11.1 h1:xRC8Iq1yyca5ypa9n1EZnWZkt7dwcoRPQwX/5gwa
 github.com/prometheus/procfs v0.11.1/go.mod h1:eesXgaPo1q7lBpVMoMy0ZOFTth9hBn4W/y0/p/ScXhY=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
 github.com/rogpeppe/go-internal v1.8.0/go.mod h1:WmiCO8CzOY8rg0OYDC4/i/2WRWAB6poM+XZ2dLUbcbE=
-github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
-github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
+github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
 github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

pkg/common/middleware/logger.go

@@ -0,0 +1,17 @@
+package middleware
+
+import "github.com/sirupsen/logrus"
+
+type LoggerI interface {
+	Info(args ...interface{})
+	Warn(args ...interface{})
+	Error(args ...interface{})
+	Fatalf(format string, args ...interface{})
+}
+
+func NewLogger() LoggerI {
+	logger := logrus.New()
+	logger.SetFormatter(&logrus.JSONFormatter{})
+	logger.SetLevel(logrus.InfoLevel)
+	return logger
+}

pkg/common/middleware/middleware.go

@@ -1,83 +1,14 @@
 package middleware
 
 import (
-	"fmt"
-	"log"
 	"time"
 
-	"github.com/gilperopiola/go-rest-example/pkg/common/config"
-	"github.com/gilperopiola/go-rest-example/pkg/common/metrics"
-	"github.com/sirupsen/logrus"
-
 	"github.com/gin-contrib/cors"
 	"github.com/gin-contrib/timeout"
 	"github.com/gin-gonic/gin"
-	"github.com/newrelic/go-agent/v3/integrations/nrgin"
-	"github.com/newrelic/go-agent/v3/newrelic"
 )
 
-type LoggerI interface {
-	Info(args ...interface{})
-	Warn(args ...interface{})
-	Error(args ...interface{})
-	Fatalf(format string, args ...interface{})
-}
-
-func NewLogger() LoggerI {
-	logger := logrus.New()
-	logger.SetFormatter(&logrus.JSONFormatter{})
-	logger.SetLevel(logrus.InfoLevel)
-	return logger
-}
-
-type Middlewares struct {
-	LoggerToCtx gin.HandlerFunc
-	Monitoring  gin.HandlerFunc
-	Prometheus  gin.HandlerFunc
-}
-
-func NewPrometheusMiddleware(metrics *metrics.Metrics) gin.HandlerFunc {
-	return func(c *gin.Context) {
-		c.Next()
-
-		// Don't log calls to /metrics
-		if c.Request.URL.Path == "/metrics" {
-			return
-		}
-
-		// HTTP Response Status
-		status := fmt.Sprint(c.Writer.Status())
-
-		metrics.RequestsTotal.WithLabelValues(c.Request.Method, c.Request.URL.Path, status).Inc()
-	}
-}
-
-func NewMonitoringMiddleware(config config.Monitoring) gin.HandlerFunc {
-
-	// If monitoring is not enabled, return empty middleware
-	if !config.Enabled {
-		return gin.HandlerFunc(func(c *gin.Context) {})
-	}
-
-	// If monitoring is enabled, use license to create New Relic app
-	license := config.Secret
-	if license == "" {
-		log.Fatalf("New Relic license not found")
-	}
-
-	newRelicApp, err := newrelic.NewApplication(
-		newrelic.ConfigAppName(config.AppName),
-		newrelic.ConfigLicense(license),
-		newrelic.ConfigAppLogForwardingEnabled(true),
-	)
-
-	// Panic on failure
-	if err != nil {
-		log.Fatalf("Failed to start New Relic: %v", err)
-	}
-
-	return nrgin.Middleware(newRelicApp)
-}
+type Middlewares []gin.HandlerFunc
 
 func NewTimeoutMiddleware(timeoutSeconds int) gin.HandlerFunc {
 	return timeout.New(

pkg/common/middleware/new_relic.go

@@ -0,0 +1,43 @@
+package middleware
+
+import (
+	"log"
+
+	"github.com/gilperopiola/go-rest-example/pkg/common/config"
+	"github.com/gin-gonic/gin"
+
+	"github.com/newrelic/go-agent/v3/integrations/nrgin"
+	"github.com/newrelic/go-agent/v3/newrelic"
+)
+
+func NewNewRelicMiddleware(app *newrelic.Application) gin.HandlerFunc {
+	return nrgin.Middleware(app)
+}
+
+func NewMonitoringNewRelic(config config.Monitoring) *newrelic.Application {
+
+	// If monitoring is not enabled, return empty middleware
+	if !config.Enabled {
+		return nil
+	}
+
+	// If monitoring is enabled, use license to create New Relic app
+	license := config.Secret
+	if license == "" {
+		log.Fatalf("New Relic license not found")
+	}
+
+	// Create app
+	newRelicApp, err := newrelic.NewApplication(
+		newrelic.ConfigAppName(config.AppName),
+		newrelic.ConfigLicense(license),
+		newrelic.ConfigAppLogForwardingEnabled(true),
+	)
+
+	// Panic on failure
+	if err != nil {
+		log.Fatalf("Failed to start New Relic: %v", err)
+	}
+
+	return newRelicApp
+}