feat(grpc): make grpc max rcv/send message size configurable

Signed-off-by: Elliot Maincourt <e.maincourt@gmail.com>
open-policy-agent · Mar 24, 2022 · d0acc43 · d0acc43
1 parent 2977de0
commit d0acc43
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Showing 2 changed files with 57 additions and 14 deletions.
diff --git a/internal/internal.go b/internal/internal.go
@@ -7,6 +7,7 @@ package internal
 import (
 	"context"
 	"fmt"
+	"math"
 	"net"
 	"net/url"
 	"os"
@@ -47,6 +48,11 @@ const defaultPath = "envoy/authz/allow"
 const defaultDryRun = false
 const defaultEnableReflection = false
 
+// Those are the defaults from grpc-go.
+// See https://github.com/grpc/grpc-go/blob/master/server.go#L58 for more details.
+const defaultGRPCServerMaxReceiveMessageSize = 1024 * 1024 * 4
+const defaultGRPCServerMaxSendMessageSize = math.MaxInt32
+
 // PluginName is the name to register with the OPA plugin manager
 const PluginName = "envoy_ext_authz_grpc"
 
@@ -56,9 +62,11 @@ const PluginName = "envoy_ext_authz_grpc"
 func Validate(m *plugins.Manager, bs []byte) (*Config, error) {
 
 	cfg := Config{
-		Addr:             defaultAddr,
-		DryRun:           defaultDryRun,
-		EnableReflection: defaultEnableReflection,
+		Addr:               defaultAddr,
+		DryRun:             defaultDryRun,
+		EnableReflection:   defaultEnableReflection,
+		GRPCMaxRecvMsgSize: defaultGRPCServerMaxReceiveMessageSize,
+		GRPCMaxSendMsgSize: defaultGRPCServerMaxSendMessageSize,
 	}
 
 	if err := util.Unmarshal(bs, &cfg); err != nil {
@@ -104,9 +112,12 @@ func Validate(m *plugins.Manager, bs []byte) (*Config, error) {
 func New(m *plugins.Manager, cfg *Config) plugins.Plugin {
 
 	plugin := &envoyExtAuthzGrpcServer{
-		manager:                m,
-		cfg:                    *cfg,
-		server:                 grpc.NewServer(),
+		manager: m,
+		cfg:     *cfg,
+		server: grpc.NewServer(
+			grpc.MaxRecvMsgSize(cfg.GRPCMaxRecvMsgSize),
+			grpc.MaxSendMsgSize(cfg.GRPCMaxSendMsgSize),
+		),
 		preparedQueryDoOnce:    new(sync.Once),
 		interQueryBuiltinCache: iCache.NewInterQueryCache(m.InterQueryBuiltinCacheConfig()),
 	}
@@ -129,14 +140,16 @@ func New(m *plugins.Manager, cfg *Config) plugins.Plugin {
 
 // Config represents the plugin configuration.
 type Config struct {
-	Addr             string `json:"addr"`
-	Query            string `json:"query"` // Deprecated: Use Path instead
-	Path             string `json:"path"`
-	DryRun           bool   `json:"dry-run"`
-	EnableReflection bool   `json:"enable-reflection"`
-	parsedQuery      ast.Body
-	ProtoDescriptor  string `json:"proto-descriptor"`
-	protoSet         *protoregistry.Files
+	Addr               string `json:"addr"`
+	Query              string `json:"query"` // Deprecated: Use Path instead
+	Path               string `json:"path"`
+	DryRun             bool   `json:"dry-run"`
+	EnableReflection   bool   `json:"enable-reflection"`
+	parsedQuery        ast.Body
+	ProtoDescriptor    string `json:"proto-descriptor"`
+	protoSet           *protoregistry.Files
+	GRPCMaxRecvMsgSize int `json:"grpc-max-recv-msg-size"`
+	GRPCMaxSendMsgSize int `json:"grpc-max-send-msg-size"`
 }
 
 type envoyExtAuthzGrpcServer struct {

diff --git a/internal/internal_test.go b/internal/internal_test.go
@@ -940,6 +940,28 @@ func TestConfigValidWithPath(t *testing.T) {
 	}
 }
 
+func TestConfigValidWithGRPCMaxMessageSizes(t *testing.T) {
+
+	m, err := plugins.New([]byte{}, "test", inmem.New())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	in := `{"grpc-max-recv-msg-size": 1000, "grpc-max-send-msg-size": 1000}`
+	config, err := Validate(m, []byte(in))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if config.GRPCMaxRecvMsgSize != 1000 {
+		t.Fatalf("Expected GRPC max receive message size to be 1000 but got %v", config.GRPCMaxRecvMsgSize)
+	}
+
+	if config.GRPCMaxSendMsgSize != 1000 {
+		t.Fatalf("Expected GRPC max send message size to be 1000 but got %v", config.GRPCMaxSendMsgSize)
+	}
+}
+
 func TestConfigValidDefault(t *testing.T) {
 
 	m, err := plugins.New([]byte{}, "test", inmem.New())
@@ -976,6 +998,14 @@ func TestConfigValidDefault(t *testing.T) {
 	if config.EnableReflection {
 		t.Fatal("Expected enable-reflection config to be disabled by default")
 	}
+
+	if config.GRPCMaxRecvMsgSize != defaultGRPCServerMaxReceiveMessageSize {
+		t.Fatalf("Expected GRPC max receive message size %d but got %d", defaultGRPCServerMaxReceiveMessageSize, config.GRPCMaxRecvMsgSize)
+	}
+
+	if config.GRPCMaxSendMsgSize != defaultGRPCServerMaxSendMessageSize {
+		t.Fatalf("Expected GRPC max send message size %d but got %d", defaultGRPCServerMaxSendMessageSize, config.GRPCMaxSendMsgSize)
+	}
 }
 
 func TestConfigInvalid(t *testing.T) {