User experience enhancements for OpenSSH options.

Support key=value syntax for OpenSSH options and show help if the -o flag is in the wrong place.
gravitational · Jan 30, 2019 · 6d78d98 · 6d78d98
1 parent 1265d4c
commit 6d78d98
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Showing 3 changed files with 33 additions and 3 deletions.
diff --git a/tool/tsh/options.go b/tool/tsh/options.go
@@ -180,11 +180,23 @@ func parseOptions(opts []string) (Options, error) {
 }
 
 func splitOption(option string) (string, string, error) {
-	parts := strings.Fields(option)
+	parts := strings.FieldsFunc(option, fieldsFunc)
 
 	if len(parts) != 2 {
 		return "", "", trace.BadParameter("invalid format for option")
 	}
 
 	return parts[0], parts[1], nil
 }
+
+// fieldsFunc splits key-value pairs off ' ' and '='.
+func fieldsFunc(c rune) bool {
+	switch {
+	case c == ' ':
+		return true
+	case c == '=':
+		return true
+	default:
+		return false
+	}
+}
diff --git a/tool/tsh/tsh.go b/tool/tsh/tsh.go
@@ -43,6 +43,8 @@ import (
 	"github.com/gravitational/teleport/lib/session"
 	"github.com/gravitational/teleport/lib/sshutils"
 	"github.com/gravitational/teleport/lib/utils"
+
+	"github.com/gravitational/kingpin"
 	"github.com/gravitational/trace"
 
 	gops "github.com/google/gops/agent"
@@ -181,6 +183,9 @@ func Run(args []string, underTest bool) {
 	app.Flag("proxy", "SSH proxy address").Envar("TELEPORT_PROXY").StringVar(&cf.Proxy)
 	app.Flag("nocache", "do not cache cluster discovery locally").Hidden().BoolVar(&cf.NoCache)
 	app.Flag("user", fmt.Sprintf("SSH proxy user [%s]", localUser)).Envar("TELEPORT_USER").StringVar(&cf.Username)
+	app.Flag("option", "").Short('o').Hidden().AllowDuplicate().PreAction(func(ctx *kingpin.ParseContext) error {
+		return trace.BadParameter("invalid flag, perhaps you want to use this flag as tsh ssh -o?")
+	}).String()
 
 	app.Flag("ttl", "Minutes to live for a SSH session").Int32Var(&cf.MinsToLive)
 	app.Flag("identity", "Identity file").Short('i').StringVar(&cf.IdentityFileIn)
@@ -206,7 +211,7 @@ func Run(args []string, underTest bool) {
 	ssh.Flag("local", "Execute command on localhost after connecting to SSH node").Default("false").BoolVar(&cf.LocalExec)
 	ssh.Flag("tty", "Allocate TTY").Short('t').BoolVar(&cf.Interactive)
 	ssh.Flag("cluster", clusterHelp).Envar(clusterEnvVar).StringVar(&cf.SiteName)
-	ssh.Flag("option", "OpenSSH options in the format used in the configuration file").Short('o').StringsVar(&cf.Options)
+	ssh.Flag("option", "OpenSSH options in the format used in the configuration file").Short('o').AllowDuplicate().StringsVar(&cf.Options)
 
 	// join
 	join := app.Command("join", "Join the active SSH session")
@@ -235,7 +240,7 @@ func Run(args []string, underTest bool) {
 	// login logs in with remote proxy and obtains a "session certificate" which gets
 	// stored in ~/.tsh directory
 	login := app.Command("login", "Log in to a cluster and retrieve the session certificate")
-	login.Flag("out", "Identity output").Short('o').StringVar(&cf.IdentityFileOut)
+	login.Flag("out", "Identity output").Short('o').AllowDuplicate().StringVar(&cf.IdentityFileOut)
 	login.Flag("format", fmt.Sprintf("Identity format [%s] or %s (for OpenSSH compatibility)",
 		client.DefaultIdentityFormat,
 		client.IdentityFormatOpenSSH)).Default(string(client.DefaultIdentityFormat)).StringVar((*string)(&cf.IdentityFormat))

diff --git a/tool/tsh/tsh_test.go b/tool/tsh/tsh_test.go
@@ -153,6 +153,19 @@ func (s *MainTestSuite) TestOptions(c *check.C) {
 				StrictHostKeyChecking: true,
 			},
 		},
+		// Valid
+		{
+			inOptions: []string{
+				"AddKeysToAgent=yes",
+			},
+			outError: false,
+			outOptions: Options{
+				AddKeysToAgent:        true,
+				ForwardAgent:          false,
+				RequestTTY:            false,
+				StrictHostKeyChecking: true,
+			},
+		},
 		// Invalid value.
 		{
 			inOptions: []string{