fix: custom timeout only for "server add"

cli/server/add.go

@@ -144,6 +144,11 @@ of your ~/.ssh/config. Checks for a valid online domain will be skipped:
 			name = internal.ValidateDomain(c)
 		}
 
+		// NOTE(d1): reasonable 5 second timeout for connections which can't
+		// succeed. The connection is attempted twice, so this results in 10
+		// seconds.
+		timeout := client.WithTimeout(5)
+
 		if local {
 			created, err := createServerDir(name)
 			if err != nil {
@@ -152,7 +157,7 @@ of your ~/.ssh/config. Checks for a valid online domain will be skipped:
 
 			logrus.Debugf("attempting to create client for %s", name)
 
-			if _, err := client.New(name); err != nil {
+			if _, err := client.New(name, timeout); err != nil {
 				cleanUp(name)
 				logrus.Fatal(err)
 			}
@@ -184,9 +189,8 @@ of your ~/.ssh/config. Checks for a valid online domain will be skipped:
 		}
 
 		logrus.Debugf("attempting to create client for %s", name)
-		if _, err := client.New(name); err != nil {
+		if _, err := client.New(name, timeout); err != nil {
 			cleanUp(name)
-			logrus.Debugf("failed to construct client for %s, saw %s", name, err.Error())
 			logrus.Fatal(sshPkg.Fatal(name, err))
 		}
 

pkg/client/client.go

@@ -16,11 +16,26 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// Conf is a Docker client configuration.
+type Conf struct {
+	Timeout int
+}
+
+// Opt is a Docker client option.
+type Opt func(c *Conf)
+
+// WithTimeout specifies a timeout for a Docker client.
+func WithTimeout(timeout int) Opt {
+	return func(c *Conf) {
+		c.Timeout = timeout
+	}
+}
+
 // New initiates a new Docker client. New client connections are validated so
 // that we ensure connections via SSH to the daemon can succeed. It takes into
 // account that you may only want the local client and not communicate via SSH.
 // For this use-case, please pass "default" as the contextName.
-func New(serverName string) (*client.Client, error) {
+func New(serverName string, opts ...Opt) (*client.Client, error) {
 	var clientOpts []client.Opt
 
 	if serverName != "default" {
@@ -34,7 +49,12 @@ func New(serverName string) (*client.Client, error) {
 			return nil, err
 		}
 
-		helper, err := commandconnPkg.NewConnectionHelper(ctxEndpoint)
+		conf := &Conf{}
+		for _, opt := range opts {
+			opt(conf)
+		}
+
+		helper, err := commandconnPkg.NewConnectionHelper(ctxEndpoint, conf.Timeout)
 		if err != nil {
 			return nil, err
 		}

pkg/ssh/ssh.go

@@ -19,7 +19,7 @@ func Fatal(hostname string, err error) error {
 	} else if strings.Contains(out, "Permission denied") {
 		return fmt.Errorf("ssh auth: permission denied for %s", hostname)
 	} else if strings.Contains(out, "Network is unreachable") {
-		return fmt.Errorf("unable to connect to %s, network is unreachable?", hostname)
+		return fmt.Errorf("unable to connect to %s, please check your SSH config", hostname)
 	}
 
 	return err

pkg/upstream/commandconn/connection.go

@@ -2,6 +2,7 @@ package commandconn
 
 import (
 	"context"
+	"fmt"
 	"net"
 	"net/url"
 
@@ -14,14 +15,17 @@ import (
 )
 
 // GetConnectionHelper returns Docker-specific connection helper for the given URL.
-// GetConnectionHelper returns nil without error when no helper is registered for the scheme.
-//
-// ssh://<host> URL requires Docker 18.09 or later on the remote host.
-func GetConnectionHelper(daemonURL string) (*connhelper.ConnectionHelper, error) {
-	return getConnectionHelper(daemonURL)
+func GetConnectionHelper(daemonURL string, timeout int) (*connhelper.ConnectionHelper, error) {
+	if timeout != 0 {
+		return getConnectionHelper(daemonURL, []string{fmt.Sprintf("-o ConnectTimeout=%v", timeout)})
+	}
+
+	return getConnectionHelper(daemonURL, []string{})
 }
 
-func getConnectionHelper(daemonURL string) (*connhelper.ConnectionHelper, error) {
+// getConnectionHelper generates a connection helper from the underlying Docker
+// libraries.
+func getConnectionHelper(daemonURL string, sshFlags []string) (*connhelper.ConnectionHelper, error) {
 	url, err := url.Parse(daemonURL)
 	if err != nil {
 		return nil, err
@@ -35,7 +39,7 @@ func getConnectionHelper(daemonURL string) (*connhelper.ConnectionHelper, error)
 
 		return &connhelper.ConnectionHelper{
 			Dialer: func(ctx context.Context, network, addr string) (net.Conn, error) {
-				return New(ctx, "ssh", ctxConnDetails.Args("docker", "system", "dial-stdio")...)
+				return New(ctx, "ssh", append(sshFlags, ctxConnDetails.Args("docker", "system", "dial-stdio")...)...)
 			},
 			Host: "http://docker.example.com",
 		}, nil
@@ -46,8 +50,8 @@ func getConnectionHelper(daemonURL string) (*connhelper.ConnectionHelper, error)
 }
 
 // NewConnectionHelper creates new connection helper for a remote docker daemon.
-func NewConnectionHelper(daemonURL string) (*connhelper.ConnectionHelper, error) {
-	helper, err := GetConnectionHelper(daemonURL)
+func NewConnectionHelper(daemonURL string, timeout int) (*connhelper.ConnectionHelper, error) {
+	helper, err := GetConnectionHelper(daemonURL, timeout)
 	if err != nil {
 		return nil, err
 	}