Added rate limiting with httprate (#193)

Author: subomi

const.go

@@ -1,5 +1,7 @@
 package convoy
 
+import "time"
+
 const (
 	HttpPost HttpMethod = "POST"
 )
@@ -10,3 +12,14 @@ const (
 	Monthly
 	Yearly
 )
+
+const (
+	// With this Convoy will not process more than 3000
+	// concurrent requests per minute. We use github.com/go-chi/httprate
+	// which uses a sliding window algorithm, so we should be fine :)
+	// TODO(subomi): We need to configure rate limiting to be per
+	// client as well as implement distributed limiting backed by
+	// a distributed key value store.
+	RATE_LIMIT          = 5000
+	RATE_LIMIT_DURATION = 1 * time.Minute
+)

docs/docs.go

@@ -1,6 +1,6 @@
 // Package docs GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
 // This file was generated by swaggo/swag at
-// 2021-10-26 23:11:32.542301 +0100 WAT m=+26.721756418
+// 2021-10-28 18:49:28.999858 +0100 WAT m=+27.284431293
 package docs
 
 import (

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/getsentry/sentry-go v0.11.0
 	github.com/ghodss/yaml v1.0.0
 	github.com/go-chi/chi/v5 v5.0.3
+	github.com/go-chi/httprate v0.5.2 // indirect
 	github.com/go-chi/render v1.0.1
 	github.com/go-redis/redis/v8 v8.11.4
 	github.com/gobeam/mongo-go-pagination v0.0.7

go.sum

@@ -105,6 +105,8 @@ github.com/gin-gonic/gin v1.4.0/go.mod h1:OW2EZn3DO8Ln9oIKOvM++LBO+5UPHJJDH72/q/
 github.com/go-check/check v0.0.0-20180628173108-788fd7840127/go.mod h1:9ES+weclKsC9YodN5RgxqK/VD9HM9JsCSh7rNhMZE98=
 github.com/go-chi/chi/v5 v5.0.3 h1:khYQBdPivkYG1s1TAzDQG1f6eX4kD2TItYVZexL5rS4=
 github.com/go-chi/chi/v5 v5.0.3/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
+github.com/go-chi/httprate v0.5.2 h1:pynJZu4jbSSHFRjpbT7EJJf8b9qt2CLZnqqKy0F+jH4=
+github.com/go-chi/httprate v0.5.2/go.mod h1:kYR4lorHX3It9tTh4eTdHhcF2bzrYnCrRNlv5+IBm2M=
 github.com/go-chi/render v1.0.1 h1:4/5tis2cKaNdnv9zFLfXzcquC9HbeZgCnxGnKrltBS8=
 github.com/go-chi/render v1.0.1/go.mod h1:pq4Rr7HbnsdaeHagklXub+p6Wd16Af5l9koip1OvJns=
 github.com/go-errors/errors v1.0.1 h1:LUHzmkK3GUKUrL/1gfBUxAHzcev3apQlezX/+O7ma6w=

server/route.go

@@ -14,6 +14,7 @@ import (
 	"github.com/frain-dev/convoy/queue"
 
 	"github.com/go-chi/chi/v5/middleware"
+	"github.com/go-chi/httprate"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	log "github.com/sirupsen/logrus"
@@ -52,6 +53,10 @@ func buildRoutes(app *applicationHandler) http.Handler {
 
 	// Public API.
 	router.Route("/api", func(v1Router chi.Router) {
+
+		// rate limit all requests.
+		v1Router.Use(httprate.LimitAll(convoy.RATE_LIMIT, convoy.RATE_LIMIT_DURATION))
+
 		v1Router.Route("/v1", func(r chi.Router) {
 			r.Use(middleware.AllowContentType("application/json"))
 			r.Use(jsonResponse)