X-Git-Url: https://gerrit.fd.io/r/gitweb?p=csit.git;a=blobdiff_plain;f=resources%2Flibraries%2Fpython%2Fssh.py;h=4bed173bbb359005c71294c5d427a8e1328d3dcd;hp=fe4404b053c6b553aea0eb1a65da30e374592c52;hb=cc85afad85339d2cc8f035ce63ff21220d8e6b96;hpb=5e7be479eacd4d1085cab152c35dcb6433a146ed diff --git a/resources/libraries/python/ssh.py b/resources/libraries/python/ssh.py index fe4404b053..4bed173bbb 100644 --- a/resources/libraries/python/ssh.py +++ b/resources/libraries/python/ssh.py @@ -60,14 +60,27 @@ class SSH(object): """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. """ - try: - 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)) + self._node = node + node_hash = self._node_hash(node) + if node_hash in SSH.__existing_connections: + self._ssh = SSH.__existing_connections[node_hash] + 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: + try: start = time() pkey = None if 'priv_key' in node: @@ -84,19 +97,14 @@ class SSH(object): 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))) - except RuntimeError as exc: - if attempts > 0: - self._reconnect(attempts-1) - else: - raise exc + 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. @@ -106,19 +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, attempts=0): - """Close the SSH connection and open it again.""" + """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, attempts) - logger.debug('Reconnecting peer done: {}'. - format(self._ssh.get_transport().getpeername())) + 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. @@ -236,8 +247,8 @@ class SSH(object): def interactive_terminal_open(self, time_out=30): """Open interactive terminal on a new channel on the connected Node. - FIXME: Convert or document other possible exceptions, such as - socket.error or SSHException. + :param time_out: Timeout in seconds. + :returns: SSH channel with opened terminal. .. warning:: Interruptingcow is used here, and it uses signal(SIGALRM) to let the operating system interrupt program @@ -245,10 +256,6 @@ class SSH(object): handlers only apply to the main thread, so you cannot use this from other threads. You must not use this in a program that uses SIGALRM itself (this includes certain profilers) - - :param time_out: Timeout in seconds. - :returns: SSH channel with opened terminal. - :raise IOError: If receive attempt results in socket.timeout. """ chan = self._ssh.get_transport().open_session() chan.get_pty() @@ -268,8 +275,7 @@ class SSH(object): break except socket.timeout: logger.error('Socket timeout: {0}'.format(buf)) - # TODO: Find out which exception would callers appreciate here. - raise IOError('Socket timeout: {0}'.format(buf)) + raise Exception('Socket timeout: {0}'.format(buf)) return chan def interactive_terminal_exec_command(self, chan, cmd, prompt): @@ -277,19 +283,18 @@ class SSH(object): interactive_terminal_open() method has to be called first! + :param chan: SSH channel with opened terminal. + :param cmd: Command to be executed. + :param prompt: Command prompt, sequence of characters used to + indicate readiness to accept commands. + :returns: Command output. + .. warning:: Interruptingcow is used here, and it uses signal(SIGALRM) to let the operating system interrupt program execution. This has the following limitations: Python signal handlers only apply to the main thread, so you cannot use this from other threads. You must not use this in a program that uses SIGALRM itself (this includes certain profilers) - - :param chan: SSH channel with opened terminal. - :param cmd: Command to be executed. - :param prompt: Command prompt, sequence of characters used to - indicate readiness to accept commands. - :returns: Command output. - :raise IOError: If receive attempt results in socket.timeout. """ chan.sendall('{c}\n'.format(c=cmd)) buf = '' @@ -305,9 +310,8 @@ class SSH(object): except socket.timeout: logger.error('Socket timeout during execution of command: ' '{0}\nBuffer content:\n{1}'.format(cmd, buf)) - # TODO: Find out which exception would callers appreciate here. - raise IOError('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', ''), '') for item in prompt: tmp.replace(item, '') @@ -321,7 +325,7 @@ class SSH(object): """ chan.close() - def scp(self, local_path, remote_path, get=False, timeout=10): + 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! @@ -360,7 +364,6 @@ class SSH(object): def exec_cmd(node, cmd, timeout=600, sudo=False): """Convenience function to ssh/exec/return rc, out & err. - FIXME: Document :param, :type, :raise and similar. Returns (rc, stdout, stderr). """ if node is None: