implement tcp and tcp+tls transports

cmd/config_connect.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"crypto/tls"
 	"fmt"
 	"net"
 
@@ -11,6 +12,7 @@ import (
 	"github.com/problame/go-netssh"
 	"github.com/problame/go-streamrpc"
 	"time"
+	"github.com/zrepl/zrepl/cmd/tlsconf"
 )
 
 type SSHStdinserverConnecter struct {
@@ -74,3 +76,79 @@ func (c *SSHStdinserverConnecter) Connect(dialCtx context.Context) (net.Conn, er
 	}
 	return netsshConnToConn{nconn}, nil
 }
+
+type TCPConnecter struct {
+	Host      string
+	Port      uint16
+	dialer    net.Dialer
+	tlsConfig *tls.Config
+}
+
+func parseTCPConnecter(i map[string]interface{}) (*TCPConnecter, error) {
+	var in struct {
+		Host        string
+		Port        uint16
+		DialTimeout string `mapstructure:"dial_timeout"`
+		TLS         map[string]interface{}
+	}
+	if err := mapstructure.Decode(i, &in); err != nil {
+		return nil, errors.Wrap(err, "mapstructure error")
+	}
+
+	if in.Host == "" || in.Port == 0 {
+		return nil, errors.New("fields 'host' and 'port' must not be empty")
+	}
+	dialTimeout, err := parsePostitiveDuration(in.DialTimeout)
+	if err != nil {
+		if in.DialTimeout != "" {
+			return nil, errors.Wrap(err, "cannot parse field 'dial_timeout'")
+		}
+		dialTimeout = 10 * time.Second
+	}
+	dialer := net.Dialer{
+		Timeout: dialTimeout,
+	}
+
+	var tlsConfig *tls.Config
+	if in.TLS != nil {
+		tlsConfig, err = func(i map[string]interface{}) (config *tls.Config, err error) {
+			var in struct {
+				CA       string
+				Cert     string
+				Key      string
+				ServerCN string `mapstructure:"server_cn"`
+			}
+			if err := mapstructure.Decode(i, &in); err != nil {
+				return nil, errors.Wrap(err, "mapstructure error")
+			}
+			if in.CA == "" || in.Cert == "" || in.Key == "" || in.ServerCN == "" {
+				return nil, errors.New("fields 'ca', 'cert', 'key' and 'server_cn' must be specified")
+			}
+
+			ca, err := tlsconf.ParseCAFile(in.CA)
+			if err != nil {
+				return nil, errors.Wrap(err, "cannot parse ca file")
+			}
+
+			cert, err := tls.LoadX509KeyPair(in.Cert, in.Key)
+			if err != nil {
+				return nil, errors.Wrap(err, "cannot parse cert/key pair")
+			}
+
+			return tlsconf.ClientAuthClient(in.ServerCN, ca, cert)
+		}(in.TLS)
+		if err != nil {
+			return nil, errors.Wrap(err, "cannot parse TLS config in field 'tls'")
+		}
+	}
+
+	return &TCPConnecter{in.Host, in.Port, dialer, tlsConfig}, nil
+}
+
+func (c *TCPConnecter) Connect(dialCtx context.Context) (conn net.Conn, err error) {
+	addr := fmt.Sprintf("%s:%d", c.Host, c.Port)
+	if c.tlsConfig != nil {
+		return tls.DialWithDialer(&c.dialer, "tcp", addr, c.tlsConfig)
+	}
+	return c.dialer.DialContext(dialCtx, "tcp", addr)
+}