Refactor for v2

Signed-off-by: Xabier Larrakoetxea <me@slok.dev>

CHANGELOG.md

@@ -2,9 +2,23 @@
 
 ## [Unreleased]
 
+Breaking change. The library has been refactored to me more flexible when adding new framework/libraries.
+
 ### Added
 
-- New middleware helper for the Echo framework
+- New middleware helper for the Echo framework.
+
+### Changed
+
+- Refactored internally how the Middleware works and gets the data to make it easier to extend and more reliable.
+  - Added `Reporter` interface as the service responsible of getting the data to be measured.
+  - All different framwork helpers now implement with the new Reporter way.
+- Fixed Gin returning duplicated data (#31).
+- Standard handler now is on `middleware/std` instead of `middleware`.
+
+### Removed
+
+- Middleware interface in favor of a struct.
 
 ## [0.6.1] - 2020-02-07
 

doc.go

@@ -11,6 +11,7 @@ the main Go net/http handler:
 		"github.com/prometheus/client_golang/prometheus/promhttp"
 		httpmetrics "github.com/slok/go-http-metrics/metrics/prometheus"
 		httpmiddleware "github.com/slok/go-http-metrics/middleware"
+		httpstdmiddleware "github.com/slok/go-http-metrics/middleware/std"
 	)
 
 	func main() {
@@ -24,7 +25,7 @@ the main Go net/http handler:
 			w.WriteHeader(http.StatusOK)
 			w.Write([]byte("hello world!"))
 		})
-		h := mdlw.Handler("", myHandler)
+		h := httpstdmiddleware.Measure("", mdlw, myHandler)
 
 		// Serve metrics.
 		log.Printf("serving metrics at: %s", ":9090")

examples/custom/main.go

@@ -11,6 +11,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	metrics "github.com/slok/go-http-metrics/metrics/prometheus"
 	"github.com/slok/go-http-metrics/middleware"
+	"github.com/slok/go-http-metrics/middleware/std"
 )
 
 const (
@@ -50,10 +51,10 @@ func main() {
 	// Wrape our middleware on each of the different handlers with the ID of the handler
 	// this way we reduce the cardinality, for example: `/test/2` and `/test/4` will
 	// have the same `handler` label on the metric: `/test/:testID`
-	mux.Handle("/", mdlw.Handler("/", rooth))
-	mux.Handle("/test/1", mdlw.Handler("/test/:testID", testh))
-	mux.Handle("/test/2", mdlw.Handler("/test/:testID", testh2))
-	mux.Handle("/other-test", mdlw.Handler("/other-test", othetesth))
+	mux.Handle("/", std.Measure("/", mdlw, rooth))
+	mux.Handle("/test/1", std.Measure("/test/:testID", mdlw, testh))
+	mux.Handle("/test/2", std.Measure("/test/:testID", mdlw, testh2))
+	mux.Handle("/other-test", std.Measure("/other-test", mdlw, othetesth))
 
 	// Serve our handler.
 	go func() {

examples/default/main.go

@@ -11,6 +11,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	metrics "github.com/slok/go-http-metrics/metrics/prometheus"
 	"github.com/slok/go-http-metrics/middleware"
+	"github.com/slok/go-http-metrics/middleware/std"
 )
 
 const (
@@ -45,7 +46,7 @@ func main() {
 
 	// Wrap our main handler, we pass empty handler ID so the middleware inferes
 	// the handler label from the URL.
-	h := mdlw.Handler("", mux)
+	h := std.Measure("", mdlw, mux)
 
 	// Serve our handler.
 	go func() {

examples/echo/main.go

@@ -28,12 +28,15 @@ func main() {
 
 	// Create Echo instance and global middleware.
 	e := echo.New()
-	e.Use(echoMiddleware.Handler("", mdlw))
+	e.Use(echoMiddleware.Measure("", mdlw))
 
 	// Add our handler.
 	e.GET("/", func(c echo.Context) error {
 		return c.String(http.StatusOK, "Hello world")
 	})
+	e.GET("/json", func(c echo.Context) error {
+		return c.JSON(http.StatusAccepted, map[string]string{"hello": "world"})
+	})
 	e.GET("/wrong", func(c echo.Context) error {
 		return c.String(http.StatusTooManyRequests, "oops")
 	})

examples/gin/main.go

@@ -27,11 +27,17 @@ func main() {
 
 	// Create Gin engine and global middleware.
 	engine := gin.New()
-	engine.Use(ginmiddleware.Handler("", mdlw))
+	engine.Use(ginmiddleware.Measure("", mdlw))
 
 	// Add our handler.
 	engine.GET("/", func(c *gin.Context) {
-		c.String(http.StatusOK, "Hello world")
+		c.String(http.StatusOK, "Hello %s", "world")
+	})
+	engine.GET("/json", func(c *gin.Context) {
+		c.JSON(http.StatusAccepted, map[string]string{"hello": "world"})
+	})
+	engine.GET("/yaml", func(c *gin.Context) {
+		c.YAML(http.StatusCreated, map[string]string{"hello": "world"})
 	})
 	engine.GET("/wrong", func(c *gin.Context) {
 		c.String(http.StatusTooManyRequests, "oops")

examples/gorestful/main.go

@@ -29,7 +29,7 @@ func main() {
 	c := gorestful.NewContainer()
 
 	// Add the middleware for all routes.
-	c.Filter(gorestfulmiddleware.Handler("", mdlw))
+	c.Filter(gorestfulmiddleware.Measure("", mdlw))
 
 	// Add our handler.
 	ws := &gorestful.WebService{}

examples/httprouter/main.go

@@ -46,9 +46,9 @@ func main() {
 	r := httprouter.New()
 
 	// Add the middleware to each route.
-	r.GET("/", httproutermiddleware.Handler("/", h, mdlw))
-	r.GET("/test/:id", httproutermiddleware.Handler("/test/:id", h1, mdlw))
-	r.GET("/test2/:id", httproutermiddleware.Handler("/test2/:id", h2, mdlw))
+	r.GET("/", httproutermiddleware.Measure("/", h, mdlw))
+	r.GET("/test/:id", httproutermiddleware.Measure("/test/:id", h1, mdlw))
+	r.GET("/test2/:id", httproutermiddleware.Measure("/test2/:id", h2, mdlw))
 
 	// Serve our handler.
 	go func() {

examples/negroni/main.go

@@ -36,7 +36,7 @@ func main() {
 	n := negroni.Classic()
 
 	// Add the middleware to negroni.
-	n.Use(negronimiddleware.Handler("", mdlw))
+	n.Use(negronimiddleware.Measure("", mdlw))
 
 	// Finally set our router on negroni.
 	n.UseHandler(mux)

examples/opencensus/main.go

@@ -10,8 +10,10 @@ import (
 
 	ocprometheus "contrib.go.opencensus.io/exporter/prometheus"
 	ocmmetrics "github.com/slok/go-http-metrics/metrics/opencensus"
-	"github.com/slok/go-http-metrics/middleware"
 	"go.opencensus.io/stats/view"
+
+	"github.com/slok/go-http-metrics/middleware"
+	"github.com/slok/go-http-metrics/middleware/std"
 )
 
 const (
@@ -52,7 +54,7 @@ func main() {
 
 	// Wrap our main handler, we pass empty handler ID so the middleware inferes
 	// the handler label from the URL.
-	h := mdlw.Handler("", mux)
+	h := std.Measure("", mdlw, mux)
 
 	// Serve our handler.
 	go func() {

internal/mocks/doc.go

@@ -4,3 +4,4 @@ Package mocks will have all the mocks of the library.
 package mocks // import "github.com/slok/go-http-metrics/internal/mocks"
 
 //go:generate mockery -output ./metrics -outpkg metrics -dir ../../metrics -name Recorder
+//go:generate mockery -output ./middleware -outpkg middleware -dir ../../middleware -name Reporter

middleware/echo/echo.go

@@ -3,17 +3,36 @@
 package echo
 
 import (
-	"net/http"
+	"context"
 
 	"github.com/labstack/echo/v4"
 	"github.com/slok/go-http-metrics/middleware"
 )
 
-// Handler returns a Echo compatible middleware from a Middleware factory instance.
-// The first handlerID argument is the same argument passed on Middleware.Handler method.
-func Handler(handlerID string, m middleware.Middleware) echo.MiddlewareFunc {
-	// Wrap wrapping handler with echo's WrapMiddleware helper
-	return echo.WrapMiddleware(func(next http.Handler) http.Handler {
-		return m.Handler(handlerID, next)
-	})
+// Measure returns a Echo measure middleware.
+func Measure(handlerID string, m middleware.Middleware) echo.MiddlewareFunc {
+	return func(h echo.HandlerFunc) echo.HandlerFunc {
+		return echo.HandlerFunc(func(c echo.Context) error {
+			r := &reporter{c: c}
+			var err error
+			m.Measure(handlerID, r, func() {
+				err = h(c)
+			})
+			return err
+		})
+	}
 }
+
+type reporter struct {
+	c echo.Context
+}
+
+func (r *reporter) Method() string { return r.c.Request().Method }
+
+func (r *reporter) Context() context.Context { return r.c.Request().Context() }
+
+func (r *reporter) URLPath() string { return r.c.Request().URL.Path }
+
+func (r *reporter) StatusCode() int { return r.c.Response().Status }
+
+func (r *reporter) BytesWritten() int64 { return r.c.Response().Size }

middleware/echo/echo_test.go

@@ -22,8 +22,7 @@ func getTestHandler(statusCode int) echo.HandlerFunc {
 }
 
 func TestMiddlewareIntegration(t *testing.T) {
-	tests := []struct {
-		name          string
+	tests := map[string]struct {
 		handlerID     string
 		statusCode    int
 		req           *http.Request
@@ -33,8 +32,7 @@ func TestMiddlewareIntegration(t *testing.T) {
 		expMethod     string
 		expStatusCode string
 	}{
-		{
-			name:          "A default HTTP middleware should call the recorder to measure.",
+		"A default HTTP middleware should call the recorder to measure.": {
 			statusCode:    http.StatusAccepted,
 			req:           httptest.NewRequest(http.MethodPost, "/test", nil),
 			expHandlerID:  "/test",
@@ -43,8 +41,8 @@ func TestMiddlewareIntegration(t *testing.T) {
 		},
 	}
 
-	for _, test := range tests {
-		t.Run(test.name, func(t *testing.T) {
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
 			assert := assert.New(t)
 
 			// Mocks.
@@ -67,7 +65,7 @@ func TestMiddlewareIntegration(t *testing.T) {
 			// Create our echo instance with the middleware.
 			mdlw := middleware.New(middleware.Config{Recorder: mr})
 			e := echo.New()
-			e.POST("/test", getTestHandler(test.statusCode), echoMiddleware.Handler("", mdlw))
+			e.POST("/test", getTestHandler(test.statusCode), echoMiddleware.Measure("", mdlw))
 
 			// Make the request.
 			resp := httptest.NewRecorder()

middleware/echo/example_test.go

@@ -27,7 +27,7 @@ func Example_echoMiddleware() {
 	h := func(c echo.Context) error {
 		return c.String(http.StatusOK, "Hello world")
 	}
-	e.GET("/", h, echoMiddleware.Handler("", mdlw))
+	e.GET("/", h, echoMiddleware.Measure("", mdlw))
 
 	// Serve metrics from the default prometheus registry.
 	log.Printf("serving metrics at: %s", ":8081")

middleware/gin/example_test.go

@@ -27,7 +27,7 @@ func Example_ginMiddleware() {
 	h := func(c *gin.Context) {
 		c.String(http.StatusOK, "Hello world")
 	}
-	engine.GET("/", ginmiddleware.Handler("", mdlw), h)
+	engine.GET("/", ginmiddleware.Measure("", mdlw), h)
 
 	// Serve metrics from the default prometheus registry.
 	log.Printf("serving metrics at: %s", ":8081")