fix: Support streaming HTTP responses (#2956)

* all: Upgrade listenerutil dependency

The new listenerutil implements http.Flusher, which is necessary
for streaming responses from the grpc-gateway to work.

* daemon/controller: Remove newline delimiter in streaming responses

The default gRPC-Gateway HTTPBody marshaler uses newlines
as a delimiter. This introduces newlines in our streamed responses.
Wrapping the default marshaler lets us define a nil delimiter, which
ensures our streaming responses are unaffected by the server side
chunking.

go.mod

@@ -38,7 +38,7 @@ require (
 	github.com/hashicorp/go-secure-stdlib/configutil/v2 v2.0.7
 	github.com/hashicorp/go-secure-stdlib/gatedwriter v0.1.1
 	github.com/hashicorp/go-secure-stdlib/kv-builder v0.1.1
-	github.com/hashicorp/go-secure-stdlib/listenerutil v0.1.5-0.20221130175209-f7789ac19a1f
+	github.com/hashicorp/go-secure-stdlib/listenerutil v0.1.5
 	github.com/hashicorp/go-secure-stdlib/mlock v0.1.1
 	github.com/hashicorp/go-secure-stdlib/parseutil v0.1.7
 	github.com/hashicorp/go-secure-stdlib/password v0.1.1

go.sum

@@ -709,8 +709,8 @@ github.com/hashicorp/go-secure-stdlib/gatedwriter v0.1.1 h1:9um9R8i0+HbRHS9d64kd
 github.com/hashicorp/go-secure-stdlib/gatedwriter v0.1.1/go.mod h1:6RoRTSMDK2H/rKh3P/JIsk1tK8aatKTt3JyvIopi3GQ=
 github.com/hashicorp/go-secure-stdlib/kv-builder v0.1.1 h1:IJgULbAXuvWxzKFfu+Au1FUmHIJulS6N4F7Hkn+Kck0=
 github.com/hashicorp/go-secure-stdlib/kv-builder v0.1.1/go.mod h1:rf5JPE13wi+NwjgsmGkbg4b2CgHq8v7Htn/F0nDe/hg=
-github.com/hashicorp/go-secure-stdlib/listenerutil v0.1.5-0.20221130175209-f7789ac19a1f h1:FemjU7MTEVt5HVI59M1AQjzEaR8mvlXr5I985BUbLSg=
-github.com/hashicorp/go-secure-stdlib/listenerutil v0.1.5-0.20221130175209-f7789ac19a1f/go.mod h1:MSXg3Md+eg1hOJFSKuTELy6YnFhfMJBVYu7t07BdPc4=
+github.com/hashicorp/go-secure-stdlib/listenerutil v0.1.5 h1:+vfyObZczNFbpGxHJWTZ+ZdTEF9boRal5rAkwKTc2yg=
+github.com/hashicorp/go-secure-stdlib/listenerutil v0.1.5/go.mod h1:MSXg3Md+eg1hOJFSKuTELy6YnFhfMJBVYu7t07BdPc4=
 github.com/hashicorp/go-secure-stdlib/mlock v0.1.1 h1:cCRo8gK7oq6A2L6LICkUZ+/a5rLiRXFMf1Qd4xSwxTc=
 github.com/hashicorp/go-secure-stdlib/mlock v0.1.1/go.mod h1:zq93CJChV6L9QTfGKtfBxKqD7BqqXx5O04A/ns2p5+I=
 github.com/hashicorp/go-secure-stdlib/parseutil v0.1.1/go.mod h1:QmrqtbKuxxSWTN3ETMPuB+VtEiBJ/A9XhoYGv8E1uD8=

internal/daemon/controller/gateway.go

@@ -39,10 +39,20 @@ func gatewayDialOptions(lis grpcServerListener) []grpc.DialOption {
 	}
 }
 
+type noDelimiterStreamingMarshaler struct {
+	runtime.Marshaler
+}
+
+func (noDelimiterStreamingMarshaler) Delimiter() []byte {
+	return nil
+}
+
 func newGrpcGatewayMux() *runtime.ServeMux {
 	return runtime.NewServeMux(
-		runtime.WithMarshalerOption(runtime.MIMEWildcard, &runtime.HTTPBodyMarshaler{
-			Marshaler: handlers.JSONMarshaler(),
+		runtime.WithMarshalerOption(runtime.MIMEWildcard, &noDelimiterStreamingMarshaler{
+			&runtime.HTTPBodyMarshaler{
+				Marshaler: handlers.JSONMarshaler(),
+			},
 		}),
 		runtime.WithErrorHandler(handlers.ErrorHandler()),
 		runtime.WithForwardResponseOption(handlers.OutgoingResponseFilter),

internal/daemon/controller/handler.go

@@ -80,7 +80,7 @@ func createMuxWithEndpoints(c *Controller, props HandlerProperties) (http.Handle
 		return p == uiPath
 	}
 
-	return http.HandlerFunc(mux.ServeHTTP), isUiRequest, nil
+	return mux, isUiRequest, nil
 }
 
 // apiHandler returns an http.Handler for the services. This can be used on

internal/daemon/controller/handler_test.go

@@ -6,8 +6,10 @@ package controller
 import (
 	"bytes"
 	"context"
+	"crypto/rand"
 	"encoding/json"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"net"
 	"net/http"
@@ -15,9 +17,13 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
 	"github.com/hashicorp/boundary/internal/daemon/controller/handlers"
+	"github.com/hashicorp/boundary/internal/errors"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"google.golang.org/genproto/googleapis/api/httpbody"
+	"google.golang.org/protobuf/proto"
 )
 
 func TestAuthenticationHandler(t *testing.T) {
@@ -347,3 +353,62 @@ func TestCallbackInterceptor(t *testing.T) {
 
 	require.NoError(t, server.Shutdown(context.Background()))
 }
+
+func TestStreamingResponse(t *testing.T) {
+	listener, err := net.Listen("tcp", ":0")
+	require.NoError(t, err)
+	t.Cleanup(func() {
+		// Ignore errors as a normal shutdown will also close the listener when
+		// the server Shutdown is called. This is just in case.
+		_ = listener.Close()
+	})
+	mux := newGrpcGatewayMux()
+	marshaler := &noDelimiterStreamingMarshaler{
+		&runtime.HTTPBodyMarshaler{
+			Marshaler: handlers.JSONMarshaler(),
+		},
+	}
+	size := 500
+	blob := make([]byte, size)
+	_, err = io.ReadFull(rand.Reader, blob)
+	require.NoError(t, err)
+	var i int
+	n := 5
+	recv := func() (proto.Message, error) {
+		t.Log("Sending chunk", i)
+		if i < n {
+			buf := make([]byte, size/n)
+			copy(buf, blob[i*len(buf):])
+			i++
+			return &httpbody.HttpBody{
+				ContentType: "application/octet-stream",
+				Data:        buf,
+			}, nil
+		}
+		return nil, io.EOF
+	}
+
+	mux.HandlePath("GET", "/", runtime.HandlerFunc(func(w http.ResponseWriter, r *http.Request, _ map[string]string) {
+		ctx := r.Context()
+		ctx = runtime.NewServerMetadataContext(ctx, runtime.ServerMetadata{})
+		runtime.ForwardResponseStream(ctx, mux, marshaler, w, r, recv)
+	}))
+
+	server := &http.Server{
+		Handler: mux,
+	}
+	go func() {
+		if err := server.Serve(listener); !errors.Is(err, http.ErrServerClosed) {
+			assert.NoError(t, err)
+		}
+	}()
+	t.Cleanup(func() {
+		require.NoError(t, server.Shutdown(context.Background()))
+	})
+	resp, err := http.Get("http://" + listener.Addr().String())
+	require.NoError(t, err)
+	read, err := io.ReadAll(resp.Body)
+	require.NoError(t, err)
+	require.True(t, string(read) == string(blob), "Got: %q", string(read))
+	require.Equal(t, i, n)
+}