[#276] Merge repo with frostfs-api-go

Signed-off-by: Pavel Pogodaev <p.pogodaev@yadro.com>

api/rpc/client/connect.go

@@ -0,0 +1,72 @@
+package client
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net"
+	"net/url"
+
+	grpcstd "google.golang.org/grpc"
+)
+
+var errInvalidEndpoint = errors.New("invalid endpoint options")
+
+func (c *Client) openGRPCConn(ctx context.Context, dialer func(ctx context.Context, cc grpcstd.ClientConnInterface) error) error {
+	if c.conn != nil {
+		return nil
+	}
+
+	if c.addr == "" {
+		return errInvalidEndpoint
+	}
+
+	var err error
+
+	c.conn, err = grpcstd.NewClient(c.addr, c.grpcDialOpts...)
+	if err != nil {
+		return fmt.Errorf("gRPC new client: %w", err)
+	}
+
+	if dialer != nil {
+		ctx, cancel := context.WithTimeout(ctx, c.dialTimeout)
+		defer cancel()
+
+		if err := dialer(ctx, c.conn); err != nil {
+			_ = c.conn.Close()
+			return fmt.Errorf("gRPC dial: %w", err)
+		}
+	}
+
+	return nil
+}
+
+// ParseURI parses s as address and returns a host and a flag
+// indicating that TLS is enabled. If multi-address is provided
+// the argument is returned unchanged.
+func ParseURI(s string) (string, bool, error) {
+	uri, err := url.ParseRequestURI(s)
+	if err != nil {
+		return s, false, nil
+	}
+
+	// check if passed string was parsed correctly
+	// URIs that do not start with a slash after the scheme are interpreted as:
+	// `scheme:opaque` => if `opaque` is not empty, then it is supposed that URI
+	// is in `host:port` format
+	if uri.Host == "" {
+		uri.Host = uri.Scheme
+		uri.Scheme = grpcScheme // assume GRPC by default
+		if uri.Opaque != "" {
+			uri.Host = net.JoinHostPort(uri.Host, uri.Opaque)
+		}
+	}
+
+	switch uri.Scheme {
+	case grpcTLSScheme, grpcScheme:
+	default:
+		return "", false, fmt.Errorf("unsupported scheme: %s", uri.Scheme)
+	}
+
+	return uri.Host, uri.Scheme == grpcTLSScheme, nil
+}