feat(core): add performance profiler (#141)

.gitignore

@@ -39,3 +39,6 @@
 core/**/main
 core/**/bin
 core/**/client
+
+# Output of pprof files
+**/*.prof

core/cmd/config.go

@@ -26,6 +26,8 @@ type ServerConfig struct {
 	TimeoutIdle  time.Duration
 
 	// Misc settings.
+	// Enable /debug/pprof endpoints.
+	Profiler       bool `env:"PROFILER"`
 	UseEnvironment bool
 	DemoMode       bool `env:"DEMO_MODE"`
 
@@ -64,6 +66,7 @@ const (
 	DefaultLoggerLevel = "info"
 
 	// Misc constants.
+	DefaultProfiler = false
 	DefaultDemoMode = false
 )
 
@@ -84,6 +87,7 @@ func NewServerConfig(useEnv bool, version string, commit string) (*ServerConfig,
 		TimeoutRead:          DefaultTimeoutRead,
 		TimeoutWrite:         DefaultTimeoutWrite,
 		TimeoutIdle:          DefaultTimeoutIdle,
+		Profiler:             DefaultProfiler,
 		UseEnvironment:       useEnv,
 		DemoMode:             DefaultDemoMode,
 		Version:              version,

core/cmd/start.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"flag"
 	"net/http"
+	"net/http/pprof"
 	"os"
 	"os/signal"
 	"strconv"
@@ -67,6 +68,7 @@ func (s *StartCommand) ParseFlags(args []string) error {
 	fs.StringVar(&s.AnalyticsDB.Host, "analyticsdb", s.AnalyticsDB.Host, "Path to analytics database.")
 
 	// Misc settings.
+	fs.BoolVar(&s.Server.Profiler, "profiler", s.Server.Profiler, "Enable debug profiling.")
 	fs.BoolVar(&s.Server.UseEnvironment, "env", false, "Opt-in to allow environment variables to be used for configuration. Flags will still override environment variables.")
 	fs.BoolVar(&s.Server.DemoMode, "demo", s.Server.DemoMode, "Enable demo mode restricting all POST/PATCH/DELETE actions (except login).")
 
@@ -150,6 +152,16 @@ func (s *StartCommand) Run(ctx context.Context) error {
 	mux.Handle("/openapi.yaml", http.FileServer(http.FS(generate.OpenAPIDocument)))
 	mux.Handle("/api/", http.StripPrefix("/api", apiHandler))
 
+	// Start CPU profiling if enabled.
+	if s.Server.Profiler {
+		log.Warn().Msg("Enabling debug profiler...")
+		mux.HandleFunc("/debug/pprof/", pprof.Index)
+		mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
+		mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
+		mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
+		mux.HandleFunc("/debug/pprof/trace", pprof.Trace)
+	}
+
 	// SPA client.
 	err = services.SetupAssetHandler(mux, service.RuntimeConfig)
 	if err != nil {

fly.toml

@@ -16,6 +16,7 @@ APP_DATABASE_HOST = '/db/app.db'
 PORT = '8080'
 LEVEL = 'debug'
 DEMO_MODE = 'true'
+PROFILER = 'true'
 
 [[mounts]]
 source = 'medama_db'