CSIT-1142 2-node topology - keywords
[csit.git] / resources / libraries / python / ssh.py
index 3a2c1b6..4bed173 100644 (file)
@@ -1,4 +1,4 @@
-# Copyright (c) 2016 Cisco and/or its affiliates.
+# Copyright (c) 2018 Cisco and/or its affiliates.
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at:
@@ -50,46 +50,61 @@ class SSH(object):
 
         :param node: Node in topology.
         :type node: dict
-        :return: IP address and port for the specified node.
+        :returns: IP address and port for the specified node.
         :rtype: int
         """
 
         return hash(frozenset([node['host'], node['port']]))
 
-    def connect(self, node):
+    def connect(self, node, attempts=5):
         """Connect to node prior to running exec_command or scp.
 
         If there already is a connection to the node, this method reuses it.
+
+        :param node: Node in topology.
+        :param attempts: Number of reconnect attempts.
+        :type node: dict
+        :type attempts: int
+        :raises IOError: If cannot connect to host.
         """
         self._node = node
         node_hash = self._node_hash(node)
         if node_hash in SSH.__existing_connections:
             self._ssh = SSH.__existing_connections[node_hash]
-            logger.debug('reusing ssh: {0}'.format(self._ssh))
+            if self._ssh.get_transport().is_active():
+                logger.debug('Reusing SSH: {ssh}'.format(ssh=self._ssh))
+            else:
+                if attempts > 0:
+                    self._reconnect(attempts-1)
+                else:
+                    raise IOError('Cannot connect to {host}'.
+                                  format(host=node['host']))
         else:
-            start = time()
-            pkey = None
-            if 'priv_key' in node:
-                pkey = RSAKey.from_private_key(
-                    StringIO.StringIO(node['priv_key']))
-
-            self._ssh = paramiko.SSHClient()
-            self._ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
-
-            self._ssh.connect(node['host'], username=node['username'],
-                              password=node.get('password'), pkey=pkey,
-                              port=node['port'])
-
-            self._ssh.get_transport().set_keepalive(10)
-
-            SSH.__existing_connections[node_hash] = self._ssh
-
-            logger.trace('connect took {} seconds'.format(time() - start))
-            logger.debug('new ssh: {0}'.format(self._ssh))
-
-        logger.debug('Connect peer: {0}'.
-                     format(self._ssh.get_transport().getpeername()))
-        logger.debug('Connections: {0}'.format(str(SSH.__existing_connections)))
+            try:
+                start = time()
+                pkey = None
+                if 'priv_key' in node:
+                    pkey = RSAKey.from_private_key(
+                        StringIO.StringIO(node['priv_key']))
+
+                self._ssh = paramiko.SSHClient()
+                self._ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
+
+                self._ssh.connect(node['host'], username=node['username'],
+                                  password=node.get('password'), pkey=pkey,
+                                  port=node['port'])
+
+                self._ssh.get_transport().set_keepalive(10)
+
+                SSH.__existing_connections[node_hash] = self._ssh
+                logger.debug('New SSH to {peer} took {total} seconds: {ssh}'.
+                             format(
+                                 peer=self._ssh.get_transport().getpeername(),
+                                 total=(time() - start),
+                                 ssh=self._ssh))
+            except SSHException:
+                raise IOError('Cannot connect to {host}'.
+                              format(host=node['host']))
 
     def disconnect(self, node):
         """Close SSH connection to the node.
@@ -99,19 +114,22 @@ class SSH(object):
         """
         node_hash = self._node_hash(node)
         if node_hash in SSH.__existing_connections:
-            logger.debug('Disconnecting peer: {}, {}'.
-                         format(node['host'], node['port']))
+            logger.debug('Disconnecting peer: {host}, {port}'.
+                         format(host=node['host'], port=node['port']))
             ssh = SSH.__existing_connections.pop(node_hash)
             ssh.close()
 
-    def _reconnect(self):
-        """Close the SSH connection and open it again."""
+    def _reconnect(self, attempts=0):
+        """Close the SSH connection and open it again.
 
+        :param attempts: Number of reconnect attempts.
+        :type attempts: int
+        """
         node = self._node
         self.disconnect(node)
-        self.connect(node)
-        logger.debug('Reconnecting peer done: {}'.
-                     format(self._ssh.get_transport().getpeername()))
+        self.connect(node, attempts)
+        logger.debug('Reconnecting peer done: {host}, {port}'.
+                     format(host=node['host'], port=node['port']))
 
     def exec_command(self, cmd, timeout=10):
         """Execute SSH command on a new channel on the connected Node.
@@ -125,21 +143,25 @@ class SSH(object):
         :rtype: tuple(int, str, str)
         :raise SSHTimeout: If command is not finished in timeout time.
         """
-        start = time()
         stdout = StringIO.StringIO()
         stderr = StringIO.StringIO()
         try:
             chan = self._ssh.get_transport().open_session(timeout=5)
+            peer = self._ssh.get_transport().getpeername()
         except AttributeError:
             self._reconnect()
             chan = self._ssh.get_transport().open_session(timeout=5)
+            peer = self._ssh.get_transport().getpeername()
         except SSHException:
             self._reconnect()
             chan = self._ssh.get_transport().open_session(timeout=5)
+            peer = self._ssh.get_transport().getpeername()
         chan.settimeout(timeout)
-        logger.trace('exec_command on {0}: {1}'
-                     .format(self._ssh.get_transport().getpeername(), cmd))
 
+        logger.trace('exec_command on {peer} with timeout {timeout}: {cmd}'
+                     .format(peer=peer, timeout=timeout, cmd=cmd))
+
+        start = time()
         chan.exec_command(cmd)
         while not chan.exit_status_ready() and timeout is not None:
             if chan.recv_ready():
@@ -150,10 +172,11 @@ class SSH(object):
 
             if time() - start > timeout:
                 raise SSHTimeout(
-                    'Timeout exception.\n'
-                    'Current contents of stdout buffer: {0}\n'
-                    'Current contents of stderr buffer: {1}\n'
-                    .format(stdout.getvalue(), stderr.getvalue())
+                    'Timeout exception during execution of command: {cmd}\n'
+                    'Current contents of stdout buffer: {stdout}\n'
+                    'Current contents of stderr buffer: {stderr}\n'
+                    .format(cmd=cmd, stdout=stdout.getvalue(),
+                            stderr=stderr.getvalue())
                 )
 
             sleep(0.1)
@@ -166,14 +189,12 @@ class SSH(object):
             stderr.write(chan.recv_stderr(self.__MAX_RECV_BUF))
 
         end = time()
-        logger.trace('exec_command on {0} took {1} seconds'.format(
-            self._ssh.get_transport().getpeername(), end-start))
+        logger.trace('exec_command on {peer} took {total} seconds'.
+                     format(peer=peer, total=end-start))
 
-        logger.trace('chan_recv/_stderr took {} seconds'.format(time()-end))
-
-        logger.trace('return RC {}'.format(return_code))
-        logger.trace('return STDOUT {}'.format(stdout.getvalue()))
-        logger.trace('return STDERR {}'.format(stderr.getvalue()))
+        logger.trace('return RC {rc}'.format(rc=return_code))
+        logger.trace('return STDOUT {stdout}'.format(stdout=stdout.getvalue()))
+        logger.trace('return STDERR {stderr}'.format(stderr=stderr.getvalue()))
         return return_code, stdout.getvalue(), stderr.getvalue()
 
     def exec_command_sudo(self, cmd, cmd_input=None, timeout=30):
@@ -182,7 +203,7 @@ class SSH(object):
         :param cmd: Command to be executed.
         :param cmd_input: Input redirected to the command.
         :param timeout: Timeout.
-        :return: return_code, stdout, stderr
+        :returns: return_code, stdout, stderr
 
         :Example:
 
@@ -200,11 +221,34 @@ class SSH(object):
             command = 'sudo -S {c} <<< "{i}"'.format(c=cmd, i=cmd_input)
         return self.exec_command(command, timeout)
 
+    def exec_command_lxc(self, lxc_cmd, lxc_name, lxc_params='', sudo=True,
+                         timeout=30):
+        """Execute command in LXC on a new SSH channel on the connected Node.
+
+        :param lxc_cmd: Command to be executed.
+        :param lxc_name: LXC name.
+        :param lxc_params: Additional parameters for LXC attach.
+        :param sudo: Run in privileged LXC mode. Default: privileged
+        :param timeout: Timeout.
+        :type lxc_cmd: str
+        :type lxc_name: str
+        :type lxc_params: str
+        :type sudo: bool
+        :type timeout: int
+        :returns: return_code, stdout, stderr
+        """
+        command = "lxc-attach {p} --name {n} -- /bin/sh -c '{c}'"\
+            .format(p=lxc_params, n=lxc_name, c=lxc_cmd)
+
+        if sudo:
+            command = 'sudo -S {c}'.format(c=command)
+        return self.exec_command(command, timeout)
+
     def interactive_terminal_open(self, time_out=30):
         """Open interactive terminal on a new channel on the connected Node.
 
         :param time_out: Timeout in seconds.
-        :return: SSH channel with opened terminal.
+        :returns: SSH channel with opened terminal.
 
         .. warning:: Interruptingcow is used here, and it uses
            signal(SIGALRM) to let the operating system interrupt program
@@ -220,7 +264,7 @@ class SSH(object):
         chan.set_combine_stderr(True)
 
         buf = ''
-        while not buf.endswith(':~$ '):
+        while not buf.endswith((":~$ ", "~]$ ", "~]# ")):
             try:
                 chunk = chan.recv(self.__MAX_RECV_BUF)
                 if not chunk:
@@ -230,6 +274,7 @@ class SSH(object):
                     logger.error('Channel exit status ready')
                     break
             except socket.timeout:
+                logger.error('Socket timeout: {0}'.format(buf))
                 raise Exception('Socket timeout: {0}'.format(buf))
         return chan
 
@@ -242,7 +287,7 @@ class SSH(object):
         :param cmd: Command to be executed.
         :param prompt: Command prompt, sequence of characters used to
         indicate readiness to accept commands.
-        :return: Command output.
+        :returns: Command output.
 
         .. warning:: Interruptingcow is used here, and it uses
            signal(SIGALRM) to let the operating system interrupt program
@@ -263,9 +308,14 @@ class SSH(object):
                     logger.error('Channel exit status ready')
                     break
             except socket.timeout:
-                raise Exception('Socket timeout: {0}'.format(buf))
+                logger.error('Socket timeout during execution of command: '
+                             '{0}\nBuffer content:\n{1}'.format(cmd, buf))
+                raise Exception('Socket timeout during execution of command: '
+                                '{0}\nBuffer content:\n{1}'.format(cmd, buf))
         tmp = buf.replace(cmd.replace('\n', ''), '')
-        return tmp.replace(prompt, '')
+        for item in prompt:
+            tmp.replace(item, '')
+        return tmp
 
     @staticmethod
     def interactive_terminal_close(chan):
@@ -275,17 +325,37 @@ class SSH(object):
         """
         chan.close()
 
-    def scp(self, local_path, remote_path):
-        """Copy files from local_path to remote_path.
+    def scp(self, local_path, remote_path, get=False, timeout=30):
+        """Copy files from local_path to remote_path or vice versa.
 
         connect() method has to be called first!
+
+        :param local_path: Path to local file that should be uploaded; or
+        path where to save remote file.
+        :param remote_path: Remote path where to place uploaded file; or
+        path to remote file which should be downloaded.
+        :param get: scp operation to perform. Default is put.
+        :param timeout: Timeout value in seconds.
+        :type local_path: str
+        :type remote_path: str
+        :type get: bool
+        :type timeout: int
         """
-        logger.trace('SCP {0} to {1}:{2}'.format(
-            local_path, self._ssh.get_transport().getpeername(), remote_path))
+        if not get:
+            logger.trace('SCP {0} to {1}:{2}'.format(
+                local_path, self._ssh.get_transport().getpeername(),
+                remote_path))
+        else:
+            logger.trace('SCP {0}:{1} to {2}'.format(
+                self._ssh.get_transport().getpeername(), remote_path,
+                local_path))
         # SCPCLient takes a paramiko transport as its only argument
-        scp = SCPClient(self._ssh.get_transport())
+        scp = SCPClient(self._ssh.get_transport(), socket_timeout=timeout)
         start = time()
-        scp.put(local_path, remote_path)
+        if not get:
+            scp.put(local_path, remote_path)
+        else:
+            scp.get(remote_path, local_path)
         scp.close()
         end = time()
         logger.trace('SCP took {0} seconds'.format(end-start))