executor/ssh: introduce TIUP_SSH_PATH,TIUP_SCP_PATH

pkg/cluster/executor/ssh.go

@@ -301,7 +301,17 @@ func (e *NativeSSHExecutor) Execute(cmd string, sudo bool, timeout ...time.Durat
 		defer cancel()
 	}
 
-	args := []string{"ssh", "-o", "StrictHostKeyChecking=no"}
+	ssh := "ssh"
+
+	if val := os.Getenv(localdata.EnvNameSSHPath); val != "" {
+		if isExec := utils.IsExecBinary(val); !isExec {
+			return nil, nil, fmt.Errorf("specified SSH in the environment variable `%s` does not exist or is not executable", localdata.EnvNameSSHPath)
+		}
+		ssh = val
+	}
+
+	args := []string{ssh, "-o", "StrictHostKeyChecking=no"}
+
 	args = e.configArgs(args) // prefix and postfix args
 	args = append(args, fmt.Sprintf("%s@%s", e.Config.User, e.Config.Host), cmd)
 
@@ -348,7 +358,16 @@ func (e *NativeSSHExecutor) Transfer(src string, dst string, download bool) erro
 		return e.ConnectionTestResult
 	}
 
-	args := []string{"scp", "-r", "-o", "StrictHostKeyChecking=no"}
+	scp := "scp"
+
+	if val := os.Getenv(localdata.EnvNameSCPPath); val != "" {
+		if isExec := utils.IsExecBinary(val); !isExec {
+			return fmt.Errorf("specified SCP in the environment variable `%s` does not exist or is not executable", localdata.EnvNameSCPPath)
+		}
+		scp = val
+	}
+
+	args := []string{scp, "-r", "-o", "StrictHostKeyChecking=no"}
 	args = e.configArgs(args) // prefix and postfix args
 
 	if download {

pkg/localdata/constant.go

@@ -67,9 +67,15 @@ const (
 	// EnvNameSSHPassPrompt is the variable name by which user specific the password prompt for sshpass
 	EnvNameSSHPassPrompt = "TIUP_SSHPASS_PROMPT"
 
-	// EnvNameNativeSSHClient is the variable name by which user can specific use natiive ssh client or not
+	// EnvNameNativeSSHClient is the variable name by which user can specific use native ssh client or not
 	EnvNameNativeSSHClient = "TIUP_NATIVE_SSH"
 
+	// EnvNameSSHPath is the variable name by which user can specific the executable ssh binary path
+	EnvNameSSHPath = "TIUP_SSH_PATH"
+
+	// EnvNameSCPPath is the variable name by which user can specific the executable scp binary path
+	EnvNameSCPPath = "TIUP_SCP_PATH"
+
 	// MetaFilename represents the process meta file name
 	MetaFilename = "tiup_process_meta"
 )

pkg/utils/ioutil.go

@@ -62,6 +62,15 @@ func IsEmptyDir(path string) (bool, error) {
 	return false, err
 }
 
+// IsExecBinary check whether a path is a valid executable
+func IsExecBinary(path string) bool {
+	info, err := os.Stat(path)
+	if err != nil {
+		return false
+	}
+	return !info.IsDir() && info.Mode()&0111 == 0111
+}
+
 // Untar decompresses the tarball
 func Untar(reader io.Reader, to string) error {
 	gr, err := gzip.NewReader(reader)

pkg/utils/ioutil_test.go

@@ -23,10 +23,14 @@ func (s *TestIOUtilSuite) TestIOUtil(c *C) {}
 
 func (s *TestIOUtilSuite) SetUpSuite(c *C) {
 	os.RemoveAll(path.Join(currentDir(), "testdata", "parent"))
+	os.RemoveAll(path.Join(currentDir(), "testdata", "ssh-exec"))
+	os.RemoveAll(path.Join(currentDir(), "testdata", "nop-nop"))
 }
 
 func (s *TestIOUtilSuite) TearDownSuite(c *C) {
 	os.RemoveAll(path.Join(currentDir(), "testdata", "parent"))
+	os.RemoveAll(path.Join(currentDir(), "testdata", "ssh-exec"))
+	os.RemoveAll(path.Join(currentDir(), "testdata", "nop-nop"))
 }
 
 func (s *TestIOUtilSuite) TestIsExist(c *C) {
@@ -39,6 +43,22 @@ func (s *TestIOUtilSuite) TestIsNotExist(c *C) {
 	c.Assert(IsNotExist("/tmp/"+uuid.New().String()), IsTrue)
 }
 
+func (s *TestIOUtilSuite) TestIsExecBinary(c *C) {
+	c.Assert(IsExecBinary("/tmp"), IsFalse)
+
+	e := path.Join(currentDir(), "testdata", "ssh-exec")
+	f, err := os.OpenFile(e, os.O_CREATE, 0777)
+	c.Assert(err, IsNil)
+	defer f.Close()
+	c.Assert(IsExecBinary(e), IsTrue)
+
+	e = path.Join(currentDir(), "testdata", "nop-nop")
+	f, err = os.OpenFile(e, os.O_CREATE, 0666)
+	c.Assert(err, IsNil)
+	defer f.Close()
+	c.Assert(IsExecBinary(e), IsFalse)
+}
+
 func (s *TestIOUtilSuite) TestUntar(c *C) {
 	c.Assert(IsNotExist(path.Join(currentDir(), "testdata", "parent")), IsTrue)
 	f, err := os.Open(path.Join(currentDir(), "testdata", "test.tar.gz"))