Add Middleware Support

pkg/app/app.go

@@ -3,6 +3,7 @@ package app
 import (
 	"context"
 	"errors"
+	"net/http"
 
 	"github.com/rs/zerolog"
 	"go.opentelemetry.io/otel/codes"
@@ -25,6 +26,7 @@ type App struct {
 
 type AppHTTP struct {
 	Funcs        []srv.HTTPFunc
+	Middleware   []http.Handler
 	HealthChecks []srv.HealthCheckFunc
 	httpDone     <-chan interface{}
 }
@@ -78,9 +80,12 @@ func (a *App) MustRun() {
 func (a *App) initHTTP() {
 	var httpShutdown shutdownFunc
 	httpShutdown, a.HTTP.httpDone = srv.MustInitHTTPServer(
-		a.AppContext,
-		a.HTTP.Funcs,
-		a.HTTP.HealthChecks...,
+		&srv.HTTPServerOpts{
+			Ctx:              a.AppContext,
+			HandleFuncs:      a.HTTP.Funcs,
+			Middleware:       a.HTTP.Middleware,
+			HealthCheckFuncs: a.HTTP.HealthChecks,
+		},
 	)
 	a.shutdownFuncs = append(a.shutdownFuncs, httpShutdown)
 }

pkg/srv/http.go

@@ -29,10 +29,17 @@ type HTTPFunc struct {
 	HandlerFunc http.HandlerFunc
 }
 
-func prepHTTPServer(ctx context.Context, handleFuncs []HTTPFunc, hcFuncs ...HealthCheckFunc) *http.Server {
+type HTTPServerOpts struct {
+	Ctx              context.Context
+	HandleFuncs      []HTTPFunc
+	Middleware       []http.Handler
+	HealthCheckFuncs []HealthCheckFunc
+}
+
+func prepHTTPServer(opts *HTTPServerOpts) *http.Server {
 	var (
-		cfg = config.MustFromCtx(ctx)
-		l   = zerolog.Ctx(ctx)
+		cfg = config.MustFromCtx(opts.Ctx)
+		l   = zerolog.Ctx(opts.Ctx)
 		mux = &http.ServeMux{}
 	)
 
@@ -43,11 +50,11 @@ func prepHTTPServer(ctx context.Context, handleFuncs []HTTPFunc, hcFuncs ...Heal
 		mux.Handle(pattern, handler) // Associate pattern with handler
 	}
 
-	healthChecks := handleHealthCheckFunc(ctx, hcFuncs...)
+	healthChecks := handleHealthCheckFunc(opts.Ctx, opts.HealthCheckFuncs...)
 	otelHandleFunc("/health", healthChecks)
 	otelHandleFunc("/", healthChecks)
 
-	for _, f := range handleFuncs {
+	for _, f := range opts.HandleFuncs {
 		otelHandleFunc(f.Path, f.HandlerFunc)
 	}
 
@@ -89,9 +96,19 @@ func prepHTTPServer(ctx context.Context, handleFuncs []HTTPFunc, hcFuncs ...Heal
 		idleTimeout = *iT
 	}
 
+	// Inject any supplied middleware
+	for i := len(opts.Middleware) - 1; i >= 0; i-- {
+		mw := opts.Middleware[i]
+		next := handler
+		handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			mw.ServeHTTP(w, r)
+			next.ServeHTTP(w, r)
+		})
+	}
+
 	// Inject logging middleware
 	if cfg.HTTP.LogRequests {
-		handler = loggingMiddleware(ctx, handler)
+		handler = loggingMiddleware(opts.Ctx, handler)
 	}
 
 	return &http.Server{
@@ -101,17 +118,17 @@ func prepHTTPServer(ctx context.Context, handleFuncs []HTTPFunc, hcFuncs ...Heal
 		IdleTimeout:  idleTimeout,
 		Handler:      handler,
 		BaseContext: func(_ net.Listener) context.Context {
-			return ctx
+			return opts.Ctx
 		},
 	}
 }
 
 // Returns a shutdown func and a done channel if the
 // server aborts abnormally. Panics on error.
-func MustInitHTTPServer(ctx context.Context, funcs []HTTPFunc, hcFuncs ...HealthCheckFunc) (
+func MustInitHTTPServer(opts *HTTPServerOpts) (
 	func(context.Context) error, <-chan interface{},
 ) {
-	shutdownFunc, doneChan, err := InitHTTPServer(ctx, funcs, hcFuncs...)
+	shutdownFunc, doneChan, err := InitHTTPServer(opts)
 	if err != nil {
 		panic(err)
 	}
@@ -120,18 +137,18 @@ func MustInitHTTPServer(ctx context.Context, funcs []HTTPFunc, hcFuncs ...Health
 
 // Returns a shutdown func and a done channel if the
 // server aborts abnormally. Returns error on failure to start
-func InitHTTPServer(ctx context.Context, funcs []HTTPFunc, hcFuncs ...HealthCheckFunc) (
+func InitHTTPServer(opts *HTTPServerOpts) (
 	func(context.Context) error, <-chan interface{}, error,
 ) {
-	l := zerolog.Ctx(ctx)
+	l := zerolog.Ctx(opts.Ctx)
 	doneChan := make(chan interface{})
 
 	var server *http.Server
 
-	httpMeter = otel.GetMeter(ctx, "http")
-	httpTracer = otel.GetTracer(ctx, "http")
+	httpMeter = otel.GetMeter(opts.Ctx, "http")
+	httpTracer = otel.GetTracer(opts.Ctx, "http")
 
-	server = prepHTTPServer(ctx, funcs, hcFuncs...)
+	server = prepHTTPServer(opts)
 
 	go func() {
 		l.Debug().Msg("HTTP Server Started")