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/exec/run.go

@@ -0,0 +1,43 @@
+package exec
+
+import (
+	"bytes"
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/juju/errors"
+	"github.com/rs/zerolog/log"
+)
+
+// Run executes anycommand in workDir and returns stdout and error.
+func Run(path string, workDir string, args ...string) (string, error) {
+	_, err := exec.LookPath(path)
+	if err != nil {
+		log.Error().Msgf("%s is required, please install it", path)
+		os.Exit(1)
+	}
+	cmd := exec.Command(path, args...)
+	cmd.Dir = workDir
+	stdout := &bytes.Buffer{}
+	stderr := &bytes.Buffer{}
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	log.Debug().Msgf("Executing " + strings.Join(cmd.Args, " "))
+	err = cmd.Run()
+	output := strings.TrimSpace(stdout.String())
+	errOut := strings.TrimSpace(stderr.String())
+	if output != "" {
+		log.Debug().Msgf(output)
+	}
+	if errOut != "" {
+		log.Debug().Msgf(errOut)
+	}
+	if _, ok := err.(*exec.ExitError); !ok {
+		return output, errors.Trace(err)
+	}
+	if err != nil {
+		return output, errors.Annotatef(err, path, cmd.Args, errOut)
+	}
+	return output, nil
+}