feat: add pprof endpoints (#454)

Author: morremeyer

.air.toml

@@ -2,4 +2,4 @@
   delay = 3000
 
   # The default port for the frontend devserver is 3000, therefore we always set the value here
-  full_bin = "API_URL=http://localhost:8080 CORS_ALLOW_ORIGINS=http://localhost:3000 ./tmp/main"
+  full_bin = "ENABLE_PPROF=true API_URL=http://localhost:8080 CORS_ALLOW_ORIGINS=http://localhost:3000 ./tmp/main"

.vscode/launch.json

@@ -11,7 +11,8 @@
       "env": {
         "GIN_MODE": "debug",
         "API_URL": "http://localhost:8080",
-        "CORS_ALLOW_ORIGINS": "http://localhost:3000"
+        "CORS_ALLOW_ORIGINS": "http://localhost:3000",
+        "ENABLE_PPROF": "true"
       },
       "console": "integratedTerminal"
     }

README.md

@@ -25,13 +25,14 @@ See [docs/upgrading.md](docs/upgrading.md).
 
 The backend can be configured with the following environment variables.
 
-| Name                 | Type                      | Default                                              | Description                                                                                                                                                       |
-| -------------------- | ------------------------- | ---------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| `API_URL`            | `string`                  | _none, must be set_                                  | The URL of the API, e.g. `https://ez.example.com/api`                                                                                                             |
-| `GIN_MODE`           | One of `release`, `debug` | `release`                                            | The mode that gin runs in. Only set this to `debug` on your development environment!                                                                              |
-| `PORT`               | `number`                  | `8080`                                               | The port the backend listens on                                                                                                                                   |
-| `LOG_FORMAT`         | One of `json`, `human`    | `json` if `GIN_MODE` is `release`, otherwise `human` | If log output is written human readable or as JSON.                                                                                                               |
-| `CORS_ALLOW_ORIGINS` | `string`                  | `""`                                                 | hosts that are allowed to use cross origin requests, separated by spaces. Only set this when your frontend runs on a different host and/or port than the backend! |
+| Name                 | Type                      | Default                                              | Description                                                                                                                                                         |
+| -------------------- | ------------------------- | ---------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `API_URL`            | `string`                  | _none, must be set_                                  | The URL of the API, e.g. `https://ez.example.com/api`                                                                                                               |
+| `GIN_MODE`           | One of `release`, `debug` | `release`                                            | The mode that gin runs in. Only set this to `debug` on your development environment!                                                                                |
+| `PORT`               | `number`                  | `8080`                                               | The port the backend listens on                                                                                                                                     |
+| `LOG_FORMAT`         | One of `json`, `human`    | `json` if `GIN_MODE` is `release`, otherwise `human` | If log output is written human readable or as JSON.                                                                                                                 |
+| `CORS_ALLOW_ORIGINS` | `string`                  | `""`                                                 | hosts that are allowed to use cross origin requests, separated by spaces. Only set this when your frontend runs on a different host and/or port than the backend!   |
+| `ENABLE_PPROF`       | `bool`                    | `false`                                              | If set to `true`, pprof profiles for application profiling are made available at `/debug/pprof`. :warning: If you do not know what this means, do not turn this on. |
 
 ### Deployment methods
 

go.mod

@@ -21,6 +21,8 @@ require (
 	gorm.io/gorm v1.24.1
 )
 
+require github.com/gin-contrib/pprof v1.4.0
+
 require (
 	github.com/KyleBanks/depth v1.2.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect

go.sum

@@ -19,6 +19,8 @@ github.com/gin-contrib/gzip v0.0.6 h1:NjcunTcGAj5CO1gn4N8jHOSIeRFHIbn51z6K+xaN4d
 github.com/gin-contrib/gzip v0.0.6/go.mod h1:QOJlmV2xmayAjkNS2Y8NQsMneuRShOU/kjovCXNuzzk=
 github.com/gin-contrib/logger v0.2.5 h1:nl6dfoCafxNmXkY3JGZvr1+ky+W8mlVz4YRkyh2Mkg0=
 github.com/gin-contrib/logger v0.2.5/go.mod h1:GozUC4j0E1cF+jTjouvD3tHmYmxyg1Wz6LqKYR+D1aM=
+github.com/gin-contrib/pprof v1.4.0 h1:XxiBSf5jWZ5i16lNOPbMTVdgHBdhfGRD5PZ1LWazzvg=
+github.com/gin-contrib/pprof v1.4.0/go.mod h1:RrehPJasUVBPK6yTUwOl8/NP6i0vbUgmxtis+Z5KE90=
 github.com/gin-contrib/requestid v0.0.6 h1:mGcxTnHQ45F6QU5HQRgQUDsAfHprD3P7g2uZ4cSZo9o=
 github.com/gin-contrib/requestid v0.0.6/go.mod h1:9i4vKATX/CdggbkY252dPVasgVucy/ggBeELXuQztm4=
 github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE=

pkg/router/router.go

@@ -13,6 +13,7 @@ import (
 	"github.com/envelope-zero/backend/pkg/httputil"
 	"github.com/gin-contrib/cors"
 	"github.com/gin-contrib/logger"
+	"github.com/gin-contrib/pprof"
 	"github.com/gin-contrib/requestid"
 	"github.com/gin-gonic/gin"
 	"github.com/rs/zerolog"
@@ -107,9 +108,14 @@ func AttachRoutes(co controllers.Controller, group *gin.RouterGroup) {
 	group.GET("", GetRoot)
 	group.OPTIONS("", OptionsRoot)
 	group.GET("/version", GetVersion)
-
 	group.OPTIONS("/version", OptionsVersion)
 
+	// pprof performance profiles
+	enablePprof, ok := os.LookupEnv("ENABLE_PPROF")
+	if ok && enablePprof == "true" {
+		pprof.RouteRegister(group, "debug/pprof")
+	}
+
 	group.GET("/docs/*any", ginSwagger.WrapHandler(swaggerFiles.Handler))
 
 	// API v1 setup

pkg/router/router_test.go

@@ -43,6 +43,25 @@ func TestGinMode(t *testing.T) {
 	os.Unsetenv("API_URL")
 }
 
+func TetsPprofOff(t *testing.T) {
+	os.Setenv("ENABLE_PPROF", "false")
+	os.Setenv("API_URL", "http://example.com")
+
+	r, err := router.Config()
+	assert.Nil(t, err, "Error on router initialization")
+
+	db, err := database.Connect(":memory:?_pragma=foreign_keys(1)")
+	assert.Nil(t, err, "Error on database connection")
+
+	router.AttachRoutes(controllers.Controller{DB: db}, r.Group("/"))
+
+	for _, r := range r.Routes() {
+		assert.NotContains(t, r.Path, "pprof", "pprof routes are registered erroneously! Route: %s", r)
+	}
+
+	os.Unsetenv("ENABLE_PPROF")
+}
+
 func TestEnvUnset(t *testing.T) {
 	_, err := router.Config()