service: add react web app serving option

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

service/options.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"crypto/x509"
+	"embed"
 	"fmt"
 	"io/ioutil"
 	"net"
@@ -352,6 +353,17 @@ func WithGatewayOpts(opts ...runtime.ServeMuxOption) Option {
 	}
 }
 
+// WithReactUI add static single page app serving to the http server
+// subpath is the path in the read-only file embed.FS to use as root to serve
+// static content
+func WithReactUI(fs embed.FS, subpath string) Option {
+	return func(o *options) {
+		o.reactUI = fs
+		o.reactUISubPath = subpath
+		o.hasReactUI = true
+	}
+}
+
 type options struct {
 	ctx     context.Context
 	name    string
@@ -394,6 +406,10 @@ type options struct {
 	gatewayOpts   []runtime.ServeMuxOption
 	cors          cors.Options
 
+	reactUI        embed.FS
+	reactUISubPath string
+	hasReactUI     bool
+
 	error         error
 	gatewayPrefix string
 }