Add custom http listener support

pkg/app/app.go

@@ -3,6 +3,7 @@ package app
 import (
 	"context"
 	"errors"
+	"net"
 	"net/http"
 
 	"github.com/rs/zerolog"
@@ -25,10 +26,11 @@ type App struct {
 }
 
 type AppHTTP struct {
-	Funcs        []srv.HTTPFunc
-	Middleware   []http.Handler
-	HealthChecks []srv.HealthCheckFunc
-	httpDone     <-chan interface{}
+	Funcs          []srv.HTTPFunc        // Handle funcs to serve
+	Middleware     []http.Handler        // Optional middleware. Next handler called by app framework.
+	HealthChecks   []srv.HealthCheckFunc // Health-check functions to be called by health endpoint
+	CustomListener net.Listener          // Optional listener for http server
+	httpDone       <-chan interface{}
 }
 
 type (
@@ -85,6 +87,7 @@ func (a *App) initHTTP() {
 			HandleFuncs:      a.HTTP.Funcs,
 			Middleware:       a.HTTP.Middleware,
 			HealthCheckFuncs: a.HTTP.HealthChecks,
+			CustomListener:   a.HTTP.CustomListener,
 		},
 	)
 	a.shutdownFuncs = append(a.shutdownFuncs, httpShutdown)

pkg/srv/http.go

@@ -37,6 +37,7 @@ type HTTPServerOpts struct {
 	HandleFuncs      []HTTPFunc
 	Middleware       []http.Handler
 	HealthCheckFuncs []HealthCheckFunc
+	CustomListener   net.Listener
 }
 
 func prepHTTPServer(opts *HTTPServerOpts) *http.Server {
@@ -155,16 +156,26 @@ func InitHTTPServer(opts *HTTPServerOpts) (
 	server = prepHTTPServer(opts)
 
 	go func() {
-		l.Debug().Msg("HTTP Server Started")
-		err := server.ListenAndServe()
+		var err error
+
+		if opts.CustomListener != nil {
+			err = server.Serve(opts.CustomListener)
+		} else {
+			err = server.ListenAndServe()
+		}
+
 		if err != nil && err != http.ErrServerClosed {
 			l.Err(err).Msg("HTTP server error")
 		} else {
 			l.Info().Msg("HTTP server shut down")
 		}
+
+		// Notify app initiator
 		doneChan <- nil
 	}()
 
+	l.Debug().Msg("HTTP Server Started")
+
 	// Shut down http server with a deadline
 	return func(shutdownCtx context.Context) error {
 		l.Debug().Msg("stopping http server")