[#290] client: Add WithURIAddress option

Add `WithURIAddress` option to client.
It parses passed address with
`url.ParseRequestURI` function and
use(or not) TLS over grpc connection
based on retrieved scheme('grpc' or
'grpcs').

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

rpc/client/options.go

@@ -2,11 +2,17 @@ package client
 
 import (
 	"crypto/tls"
+	"net/url"
 	"time"
 
 	"google.golang.org/grpc"
 )
 
+const (
+	grpcScheme    = "grpc"
+	grpcTLSScheme = "grpcs"
+)
+
 // Option is a Client's option.
 type Option func(*cfg)
 
@@ -40,6 +46,44 @@ func WithNetworkAddress(v string) Option {
 	}
 }
 
+// WithNetworkURIAddress combines WithNetworkAddress and WithTLSCfg options
+// based on arguments.
+//
+// Do not use along with WithNetworkAddress and WithTLSCfg.
+//
+// Ignored if WithGRPCConn is provided.
+func WithNetworkURIAddress(addr string, tlsCfg *tls.Config) []Option {
+	uri, err := url.ParseRequestURI(addr)
+	if err != nil {
+		return []Option{WithNetworkAddress(addr)}
+	}
+
+	// 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.Opaque != "" {
+		return []Option{WithNetworkAddress(addr)}
+	}
+
+	switch uri.Scheme {
+	case grpcScheme:
+		tlsCfg = nil
+	case grpcTLSScheme:
+		if tlsCfg == nil {
+			tlsCfg = &tls.Config{}
+		}
+	default:
+		// not supported scheme
+		return nil
+	}
+
+	return []Option{
+		WithNetworkAddress(uri.Host),
+		WithTLSCfg(tlsCfg),
+	}
+}
+
 // WithDialTimeout returns option to specify
 // dial timeout of the remote server connection.
 //
@@ -58,9 +102,7 @@ func WithDialTimeout(v time.Duration) Option {
 // Ignored if WithGRPCConn is provided.
 func WithTLSCfg(v *tls.Config) Option {
 	return func(c *cfg) {
-		if v != nil {
-			c.tlsCfg = v
-		}
+		c.tlsCfg = v
 	}
 }