Add initial prototype (#1)

* Add survey library to select server

* Add speedtest

* Add --random flag to connect

* Add list command

* Cache server list

* Tail the openvpn logs so that it appears in vpngate logs

* Add goreleaser action

* Add golangci-lint action

pkg/vpn/client.go

@@ -0,0 +1,48 @@
+package vpn
+
+import (
+	"io/ioutil"
+	"os"
+	"time"
+
+	"github.com/davegallant/vpngate/pkg/exec"
+	"github.com/davegallant/vpngate/pkg/network"
+	"github.com/hpcloud/tail"
+	"github.com/juju/errors"
+	"github.com/rs/zerolog/log"
+)
+
+// Connect to a specified OpenVPN configuration
+func Connect(configPath string) error {
+
+	tmpLogFile, err := ioutil.TempFile("", "vpngate-openvpn-log-")
+	if err != nil {
+		return errors.Annotate(err, "Unable to create a temporary log file")
+	}
+	defer os.Remove(tmpLogFile.Name())
+
+	go func() {
+		for {
+			err = network.TestSpeed()
+			if err != nil {
+				log.Error().Msg("Failed to test network speed")
+			}
+			time.Sleep(time.Minute)
+		}
+
+	}()
+
+	go func() {
+		// Tail the temporary openvpn log file
+		t, err := tail.TailFile(tmpLogFile.Name(), tail.Config{Follow: true})
+		if err != nil {
+			log.Error().Msgf("%s", err)
+		}
+		for line := range t.Lines {
+			log.Debug().Msg(line.Text)
+		}
+	}()
+
+	_, err = exec.Run("openvpn", ".", "--verb", "4", "--log", tmpLogFile.Name(), "--config", configPath)
+	return err
+}