fix: add CORS setup

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/golang/protobuf v1.3.1
 	github.com/opentracing/opentracing-go v1.2.0 // indirect
 	github.com/pkg/errors v0.9.1
+	github.com/rs/cors v1.7.0 // indirect
 	github.com/shurcooL/httpfs v0.0.0-20190707220628-8d4bc4ba7749
 	github.com/shurcooL/vfsgen v0.0.0-20181202132449-6a9ea43bcacd
 	github.com/spf13/cobra v1.0.0

go.sum

@@ -121,6 +121,8 @@ github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R
 github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
+github.com/rs/cors v1.7.0 h1:+88SsELBHx5r+hZ8TCkggzSstaWNbDvThkVK8H6f9ik=
+github.com/rs/cors v1.7.0/go.mod h1:gFx+x8UowdsKA9AchylcLynDq+nNFfI8FkUZdN/jGCU=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/segmentio/ksuid v1.0.2 h1:9yBfKyw4ECGTdALaF09Snw3sLJmYIX6AbPJrAy6MrDc=
 github.com/segmentio/ksuid v1.0.2/go.mod h1:BXuJDr2byAiHuQaQtSKoXh1J0YmUDurywOXgB2w+OSU=

internal/cmd/serve/cmd.go

@@ -21,6 +21,7 @@ import (
 	"github.com/fsnotify/fsnotify"
 	"github.com/go-chi/chi"
 	"github.com/go-chi/chi/middleware"
+	"github.com/rs/cors"
 	"github.com/spf13/cobra"
 )
 
@@ -190,7 +191,12 @@ func watchFile(filename string, onChange func(in fsnotify.Event)) (*fsnotify.Wat
 
 func startServer(config *config.Config) error {
 	postProcess(config)
-	server, err := gateway.StartHttpListener(config.Listen, http.NewServeMux())
+	c := cors.New(cors.Options{
+		AllowedOrigins: []string{"*"},
+	})
+	mux := http.NewServeMux()
+	handler := c.Handler(mux)
+	server, err := gateway.StartHttpListener(config.Listen, handler)
 	if err != nil {
 		return err
 	}