Constrain GRPC load balancing to services already using it

weaveworks · Sep 19, 2018 · dfba8f2 · dfba8f2
1 parent f15aebe
commit dfba8f2
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Showing 5 changed files with 20 additions and 11 deletions.
diff --git a/common/billing/grpc/client.go b/common/billing/grpc/client.go
@@ -54,7 +54,7 @@ func init() {
 // NewClient creates... a new client.
 func NewClient(cfg Config) (*Client, error) {
 	log.WithField("url", cfg.HostPort).Infof("creating gRPC client")
-	conn, err := common_grpc.NewInsecureConn(cfg.HostPort, "", durationCollector)
+	conn, err := common_grpc.NewInsecureConn(cfg.HostPort, false, "", durationCollector)
 	if err != nil {
 		return nil, err
 	}

diff --git a/common/grpc/client.go b/common/grpc/client.go
@@ -28,19 +28,28 @@ func instrumetation(errorKey string, durationCollector *instrument.HistogramColl
 	}
 }
 
-func dial(url string, opts ...grpc.DialOption) (*grpc.ClientConn, error) {
-	address, dialOptions, err := server.ParseURL(url)
-	if err != nil {
-		return nil, err
+func dial(urlOrHostPort string, loadBalance bool, opts ...grpc.DialOption) (*grpc.ClientConn, error) {
+	var dialOptions []grpc.DialOption
+	var address string
+	// Passing this flag is a bit ugly, but we might re-do the load balancing soon
+	if loadBalance {
+		var err error
+		address, dialOptions, err = server.ParseURL(urlOrHostPort)
+		if err != nil {
+			return nil, err
+		}
+		dialOptions = append(dialOptions, opts...)
+	} else {
+		dialOptions = opts
+		address = urlOrHostPort
 	}
-	dialOptions = append(dialOptions, opts...)
 	return grpc.Dial(address, dialOptions...)
 }
 
 // NewInsecureConn instantiates ClientConn with middleware.
-func NewInsecureConn(url string, errorKey string, durationCollector *instrument.HistogramCollector) (*grpc.ClientConn, error) {
+func NewInsecureConn(urlOrHostPort string, loadBalance bool, errorKey string, durationCollector *instrument.HistogramCollector) (*grpc.ClientConn, error) {
 	opts := append(
 		[]grpc.DialOption{grpc.WithInsecure()},
 		instrumetation(errorKey, durationCollector)...)
-	return dial(url, opts...)
+	return dial(urlOrHostPort, loadBalance, opts...)
 }
diff --git a/common/users/client.go b/common/users/client.go
@@ -45,7 +45,7 @@ func init() {
 
 // NewClient instantiates Client.
 func NewClient(cfg Config) (*Client, error) {
-	conn, err := common_grpc.NewInsecureConn(cfg.HostPort, UsersErrorCode, durationCollector)
+	conn, err := common_grpc.NewInsecureConn(cfg.HostPort, true, UsersErrorCode, durationCollector)
 	if err != nil {
 		return nil, err
 	}

diff --git a/users-sync/api/client.go b/users-sync/api/client.go
@@ -48,7 +48,7 @@ type Client struct {
 
 // NewClient instantiates Client.
 func NewClient(cfg Config) (CloseableUsersSyncClient, error) {
-	conn, err := common_grpc.NewInsecureConn(cfg.HostPort, "", durationCollector)
+	conn, err := common_grpc.NewInsecureConn(cfg.HostPort, false, "", durationCollector)
 	if err != nil {
 		return nil, err
 	}

diff --git a/users/client/client.go b/users/client/client.go
@@ -30,7 +30,7 @@ func New(kind, address string, opts CachingClientConfig) (users.UsersClient, err
 }
 
 func newGRPCClient(address string) (users.UsersClient, error) {
-	conn, err := common_grpc.NewInsecureConn(address, "", nil)
+	conn, err := common_grpc.NewInsecureConn(address, true, "", nil)
 	if err != nil {
 		return nil, err
 	}