fix: stream output from remote ssh commands

cli/server/add.go

@@ -225,14 +225,12 @@ func installDocker(c *cli.Context, cl *dockerClient.Client, sshCl *simplessh.Cli
 				return err
 			}
 			logrus.Debugf("running '%s' on %s now with sudo password", cmd, domainName)
-			_, err := sshCl.ExecSudo(cmd, sudoPass)
-			if err != nil {
+			if err := ssh.RunSudoCmd(cmd, sudoPass, sshCl); err != nil {
 				return err
 			}
 		} else {
 			logrus.Debugf("running '%s' on %s now without sudo password", cmd, domainName)
-			_, err := sshCl.Exec(cmd)
-			if err != nil {
+			if err := ssh.Exec(cmd, sshCl); err != nil {
 				return err
 			}
 		}

pkg/ssh/ssh.go

@@ -1,7 +1,12 @@
 package ssh
 
 import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
 	"os/user"
+	"sync"
 	"time"
 
 	"github.com/AlecAivazis/survey/v2"
@@ -94,3 +99,128 @@ func New(domainName, sshAuth, username, port string) (*simplessh.Client, error)
 
 	return client, nil
 }
+
+// sudoWriter supports sudo command handling.
+// https://github.com/sfreiberg/simplessh/blob/master/simplessh.go
+type sudoWriter struct {
+	b     bytes.Buffer
+	pw    string
+	stdin io.Writer
+	m     sync.Mutex
+}
+
+// Write satisfies the write interface for sudoWriter.
+// https://github.com/sfreiberg/simplessh/blob/master/simplessh.go
+func (w *sudoWriter) Write(p []byte) (int, error) {
+	if string(p) == "sudo_password" {
+		w.stdin.Write([]byte(w.pw + "\n"))
+		w.pw = ""
+		return len(p), nil
+	}
+
+	w.m.Lock()
+	defer w.m.Unlock()
+
+	return w.b.Write(p)
+}
+
+// RunSudoCmd runs SSH commands and streams output.
+// https://github.com/sfreiberg/simplessh/blob/master/simplessh.go
+func RunSudoCmd(cmd, passwd string, cl *simplessh.Client) error {
+	session, err := cl.SSHClient.NewSession()
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+
+	cmd = "sudo -p " + "sudo_password" + " -S " + cmd
+
+	w := &sudoWriter{
+		pw: passwd,
+	}
+	w.stdin, err = session.StdinPipe()
+	if err != nil {
+		return err
+	}
+
+	session.Stdout = w
+	session.Stderr = w
+
+	done := make(chan struct{})
+	scanner := bufio.NewScanner(session.Stdin)
+
+	go func() {
+		for scanner.Scan() {
+			line := scanner.Text()
+			fmt.Println(line)
+		}
+		done <- struct{}{}
+	}()
+
+	if err := session.Start(cmd); err != nil {
+		return err
+	}
+
+	<-done
+
+	if err := session.Wait(); err != nil {
+		return err
+	}
+
+	return err
+}
+
+// Exec runs a command on a remote and streams output.
+// https://github.com/sfreiberg/simplessh/blob/master/simplessh.go
+func Exec(cmd string, cl *simplessh.Client) error {
+	session, err := cl.SSHClient.NewSession()
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+
+	stdout, err := session.StdoutPipe()
+	if err != nil {
+		return err
+	}
+
+	stderr, err := session.StdoutPipe()
+	if err != nil {
+		return err
+	}
+
+	stdoutDone := make(chan struct{})
+	stdoutScanner := bufio.NewScanner(stdout)
+
+	go func() {
+		for stdoutScanner.Scan() {
+			line := stdoutScanner.Text()
+			fmt.Println(line)
+		}
+		stdoutDone <- struct{}{}
+	}()
+
+	stderrDone := make(chan struct{})
+	stderrScanner := bufio.NewScanner(stderr)
+
+	go func() {
+		for stderrScanner.Scan() {
+			line := stderrScanner.Text()
+			fmt.Println(line)
+		}
+		stderrDone <- struct{}{}
+	}()
+
+	if err := session.Start(cmd); err != nil {
+		return err
+	}
+
+	<-stdoutDone
+	<-stderrDone
+
+	if err := session.Wait(); err != nil {
+		return err
+	}
+
+	return nil
+}