[sdn_tests]: Adding ssh testhelper to pins_ondatra. (#12676)

* [sdn_tests]: Adding Build support for pins_ondatra

* [sdn_tests]: Adding binding infra to pins_ondatra.

* [sdn_tests]: Adding cert generation script and certs folder to pins_ondatra.

* [sdn_tests]: Adding Data Infra to pins_ondatra.

* [sdn_tests]: Adding gnmi testhelper to pins_ondatra.

* [sdn_tests]: Adding GNOI testhelper to pins_ondatra.

* [sdn_tests]: Adding LACP testhelper to pins_ondatra.

* [sdn_tests]: Adding P4RT testhelper to pins_ondatra.

* [sdn_tests]: Adding Platform and port_management testhelper to pins_ondatra.

* [sdn_tests]: Adding testhelper to pins_ondatra.

* [sdn_tests]: Adding Augment testhelper Infra to pins_ondatra.

* [sdn_tests]: Adding results testhelper to pins_ondatra.

* [sdn_tests]: Adding ssh testhelper to pins_ondatra.

sdn_tests/pins_ondatra/infrastructure/testhelper/BUILD.bazel

@@ -19,7 +19,7 @@ go_library(
         "platform_info.go",
         "port_management.go",
 	      "results.go",
-        "//infrastructure/testhelper/platform_info:platform_info",
+      	"ssh.go",
     ],
     data = [
         "//infrastructure/data",

sdn_tests/pins_ondatra/infrastructure/testhelper/ssh.go

@@ -0,0 +1,140 @@
+package testhelper
+
+import (
+	"fmt"
+	"time"
+	"net"
+
+	"os"
+
+	"github.com/pkg/sftp"
+	"golang.org/x/crypto/ssh"
+)
+
+const (
+	sshPort        = 22
+	sshUser        = "root"
+	defaultTimeout = 30 * time.Second
+)
+
+// Function pointers that interact with the switch or the host.
+// They enable unit testing of methods that interact with the switch or the host.
+var (
+	switchstackPrivateSSHRsaKey = func() (string, error) {
+
+		b, err := os.ReadFile("/home/user/.ssh/key")
+		return string(b), err
+	}
+
+	testhelperSSHDial = func(addr string, config *ssh.ClientConfig) (*ssh.Client, error) {
+		sshClient, err := ssh.Dial("tcp", fmt.Sprintf("[%s]:%d", addr, sshPort), config)
+		if err != nil {
+			return nil, WrapError(err, "failure to dial ssh")
+		}
+		return sshClient, nil
+	}
+
+	testhelperNewSSHSession = func(sshClient *ssh.Client) (*ssh.Session, error) {
+		sshSession, err := sshClient.NewSession()
+		if err != nil {
+			return nil, WrapError(err, "failure to create ssh session")
+		}
+		return sshSession, nil
+	}
+
+	testhelperNewSFTPClient = func(sshClient *ssh.Client) (*sftp.Client, error) {
+		sftpClient, err := sftp.NewClient(sshClient)
+		if err != nil {
+			return nil, WrapError(err, "failure to create sftp client")
+		}
+		return sftpClient, nil
+	}
+
+	testhelperCloseSSHClient = func(sshClient *ssh.Client) error {
+		return sshClient.Close()
+	}
+
+	testhelperCloseSSHSession = func(sshSession *ssh.Session) error {
+		return sshSession.Close()
+	}
+
+	testhelperCloseSFTPClient = func(sftpClient *sftp.Client) error {
+		return sftpClient.Close()
+	}
+
+	testhelperOutputSSHSession = func(sshSession *ssh.Session, cmd string) ([]byte, error) {
+		return sshSession.Output(cmd)
+	}
+)
+
+// SSHManager provides two ssh objects: ssh.Session and sftp.Client.
+type SSHManager struct {
+	sshClient  *ssh.Client
+	SSHSession *ssh.Session
+	SFTPClient *sftp.Client
+}
+
+// NewSSHManager returns a new SSHManager, which contains two ssh objects that can help in ssh & scp.
+func NewSSHManager(addr string) (*SSHManager, error) {
+	manager := &SSHManager{}
+	privKey, err := switchstackPrivateSSHRsaKey()
+	if err != nil {
+		return nil, WrapError(err, "failure to fetch ssh key")
+	}
+	signer, err := ssh.ParsePrivateKey([]byte(privKey))
+	if err != nil {
+		return nil, WrapError(err, "failure to parse ssh key")
+	}
+	authMethod := ssh.PublicKeys(signer)
+	config := &ssh.ClientConfig{
+		User:            sshUser,
+		Auth:            []ssh.AuthMethod{authMethod},
+		HostKeyCallback: customInsecureIgnoreHostKey,
+		Timeout:         defaultTimeout,
+	}
+	if manager.sshClient, err = testhelperSSHDial(addr, config); err != nil {
+		return nil, err
+	}
+	if manager.SSHSession, err = testhelperNewSSHSession(manager.sshClient); err != nil {
+		return nil, err
+	}
+	if manager.SFTPClient, err = testhelperNewSFTPClient(manager.sshClient); err != nil {
+		return nil, err
+	}
+
+	return manager, nil
+}
+// Adding a coustom InsecureIgnoreHostKey to effectivly ignore host key verification
+func customInsecureIgnoreHostKey(hostname string, remote net.Addr, key ssh.PublicKey) error {
+	return nil
+}
+// Close must be called to close the SSHManager.
+func (s *SSHManager) Close() error {
+	var err error
+	if e := testhelperCloseSSHSession(s.SSHSession); e != nil {
+		err = WrapError(e, "failure in closing ssh.Session")
+	}
+	if e := testhelperCloseSFTPClient(s.SFTPClient); e != nil {
+		err = WrapError(e, "failure in closing sftp.Client")
+	}
+	if e := testhelperCloseSSHClient(s.sshClient); e != nil {
+		err = WrapError(e, "failure in closing ssh.Client")
+	}
+	return err
+}
+
+// RunSSH runs a single SSH command on the device and returns its standard output.
+// Handles the creation and closing of SSHManager, since the underlying SSHSession can only call one
+// command.
+func RunSSH(addr string, cmd string) (string, error) {
+	m, err := NewSSHManager(addr)
+	if err != nil {
+		return "", fmt.Errorf("failed to create ssh helper: %w", err)
+	}
+	defer m.Close()
+	o, err := testhelperOutputSSHSession(m.SSHSession, cmd)
+	if err != nil {
+		return "", fmt.Errorf("failed to run command '%s', output='%s', error: %w", cmd, string(o), err)
+	}
+	return string(o[:]), nil
+}