feat: add support for grpc web

internal/cmd/target.go

@@ -12,10 +12,12 @@ const (
 	ionscaleSystemAdminKey     = "IONSCALE_ADMIN_KEY"
 	ionscaleAddr               = "IONSCALE_ADDR"
 	ionscaleInsecureSkipVerify = "IONSCALE_SKIP_VERIFY"
+	ionscaleUseGrpcWeb         = "IONSCALE_GRPC_WEB"
 )
 
 type Target struct {
 	addr               string
+	useGrpcWeb         bool
 	insecureSkipVerify bool
 	systemAdminKey     string
 }
@@ -23,11 +25,13 @@ type Target struct {
 func (t *Target) prepareCommand(cmd *coral.Command) {
 	cmd.Flags().StringVar(&t.addr, "addr", "", "Addr of the ionscale server, as a complete URL")
 	cmd.Flags().BoolVar(&t.insecureSkipVerify, "tls-skip-verify", false, "Disable verification of TLS certificates")
+	cmd.Flags().BoolVar(&t.useGrpcWeb, "grpc-web", false, "Enables gRPC-web protocol. Useful if ionscale server is behind proxy which does not support GRPC")
 	cmd.Flags().StringVar(&t.systemAdminKey, "admin-key", "", "If specified, the given value will be used as the key to generate a Bearer token for the call. This can also be specified via the IONSCALE_ADMIN_KEY environment variable.")
 }
 
 func (t *Target) createGRPCClient() (api.IonscaleClient, io.Closer, error) {
 	addr := t.getAddr()
+	useGrpcWeb := t.getUseGrpcWeb()
 	skipVerify := t.getInsecureSkipVerify()
 	systemAdminKey := t.getSystemAdminKey()
 
@@ -36,7 +40,7 @@ func (t *Target) createGRPCClient() (api.IonscaleClient, io.Closer, error) {
 		return nil, nil, err
 	}
 
-	return ionscale.NewClient(auth, addr, skipVerify)
+	return ionscale.NewClient(auth, addr, skipVerify, useGrpcWeb)
 }
 
 func (t *Target) getAddr() string {
@@ -53,6 +57,13 @@ func (t *Target) getInsecureSkipVerify() bool {
 	return config.GetBool(ionscaleInsecureSkipVerify, false)
 }
 
+func (t *Target) getUseGrpcWeb() bool {
+	if t.useGrpcWeb {
+		return true
+	}
+	return config.GetBool(ionscaleUseGrpcWeb, false)
+}
+
 func (t *Target) getSystemAdminKey() string {
 	if len(t.systemAdminKey) != 0 {
 		return t.systemAdminKey

internal/mux/mux.go

@@ -2,6 +2,7 @@ package mux
 
 import (
 	"crypto/tls"
+	"github.com/improbable-eng/grpc-web/go/grpcweb"
 	"github.com/jsiebens/ionscale/internal/config"
 	"github.com/soheilhy/cmux"
 	"golang.org/x/sync/errgroup"
@@ -26,11 +27,15 @@ func Serve(grpcServer *grpc.Server, appHandler http.Handler, metricsHandler http
 		cmux.HTTP2MatchHeaderFieldPrefixSendSettings("content-type", "application/grpc"),
 		cmux.HTTP2MatchHeaderFieldPrefixSendSettings("content-type", "application/grpc+proto"),
 	)
+	grpcWebL := mux.Match(cmux.HTTP1HeaderFieldPrefix("content-type", "application/grpc-web"))
 	httpL := mux.Match(cmux.Any())
 
+	grpcWebHandler := grpcweb.WrapServer(grpcServer)
+
 	g := new(errgroup.Group)
 
 	g.Go(func() error { return grpcServer.Serve(grpcL) })
+	g.Go(func() error { return http.Serve(grpcWebL, grpcWebHandler) })
 	g.Go(func() error { return http.Serve(httpL, appHandler) })
 	g.Go(func() error { return http.Serve(metricsL, metricsHandler) })
 	g.Go(func() error { return mux.Serve() })