Add CORS Support to allow frontend requests

main.go

@@ -7,6 +7,7 @@ import (
 	"os"
 
 	"connectrpc.com/connect"
+	connectcors "connectrpc.com/cors"
 	"connectrpc.com/grpcreflect"
 	"connectrpc.com/validate"
 	"git.kocoder.xyz/vt/shortener/internal/config"
@@ -15,6 +16,7 @@ import (
 	"git.kocoder.xyz/vt/shortener/internal/service"
 	"git.kocoder.xyz/vt/shortener/internal/telemetry"
 	_ "github.com/lib/pq"
+	"github.com/rs/cors"
 	"github.com/uptrace/opentelemetry-go-extra/otelsql"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"go.opentelemetry.io/otel/attribute"
@@ -66,8 +68,17 @@ func main() {
 
 	mux.Handle("/", srv)
 
+	c := cors.New(cors.Options{
+		AllowedOrigins: conf.ALLOWED_ORIGINS,
+		AllowedMethods: connectcors.AllowedMethods(),
+		AllowedHeaders: connectcors.AllowedHeaders(),
+		ExposedHeaders: connectcors.ExposedHeaders(),
+		MaxAge:         7200,
+	})
+	corsMux := c.Handler(mux)
+
 	// Wrap the server with OpenTelemetry HTTP handler for tracing & metrics
-	instrumentedHandler := otelhttp.NewHandler(mux, "shortener-server2")
+	instrumentedHandler := otelhttp.NewHandler(corsMux, "shortener-server2")
 
 	p := new(http.Protocols)
 	p.SetHTTP1(true)