Base Parallel Client

API documentation for common parallel client functionality.

This class is abstract and contains functions that need to be implemented for each underlying SSH library.

Abstract parallel SSH client package

class pssh.clients.base.parallel.BaseParallelSSHClient(hosts, user=None, password=None, port=None, pkey=None, allow_agent=True, num_retries=3, timeout=120, pool_size=100, host_config=None, retry_delay=5, identity_auth=True, ipv6_only=False, proxy_host=None, proxy_port=None, proxy_user=None, proxy_password=None, proxy_pkey=None, keepalive_seconds=None, cert_file=None, gssapi_auth=False, gssapi_server_identity=None, gssapi_client_identity=None, gssapi_delegate_credentials=False, forward_ssh_agent=False, _auth_thread_pool=True)

Parallel client base class.

connect_auth()

Connect to and authenticate with all hosts in parallel.

This function can be used to perform connection and authentication outside of command functions like run_command or copy_file so the two operations, login and running a remote command, can be separated.

It is not required to be called prior to any other functions.

Connections and authentication is performed in parallel by this and all other functions.

Returns:list of greenlets to joinall with.
Return type:list(gevent.greenlet.Greenlet)
copy_file(local_file, remote_file, recurse=False, copy_args=None)

Copy local file to remote file in parallel

This function returns a list of greenlets which can be join-ed on to wait for completion.

gevent.joinall() function may be used to join on all greenlets and will also raise exceptions from them if called with raise_error=True - default is False.

Alternatively call .get on each greenlet to raise any exceptions from it.

Exceptions listed here are raised when either gevent.joinall(<greenlets>, raise_error=True) is called or .get is called on each greenlet, not this function itself.

Parameters:
  • local_file (str) – Local filepath to copy to remote host
  • remote_file (str) – Remote filepath on remote host to copy file to
  • recurse (bool) – Whether or not to descend into directories recursively.
  • copy_args (tuple or list) – (Optional) format local_file and remote_file strings with per-host arguments in copy_args. copy_args length must equal length of host list - pssh.exceptions.HostArgumentError is raised otherwise
Return type:

List(gevent.Greenlet) of greenlets for remote copy commands
Raises:

ValueError when a directory is supplied to local_file and recurse is not set
Raises:

pssh.exceptions.HostArgumentError on number of per-host copy arguments not equal to number of hosts
Raises:

IOError on I/O errors writing files
Raises:

OSError on OS errors like permission denied

Note

Remote directories in remote_file that do not exist will be created as long as permissions allow.

copy_remote_file(remote_file, local_file, recurse=False, suffix_separator='_', copy_args=None, **kwargs)

Copy remote file(s) in parallel as <local_file><suffix_separator><host>

With a local_file value of myfile and default separator _ the resulting filename will be myfile_myhost for the file from host myhost.

This function, like ParallelSSHClient.copy_file(), returns a list of greenlets which can be join-ed on to wait for completion.

gevent.joinall() function may be used to join on all greenlets and will also raise exceptions if called with raise_error=True - default is False.

Alternatively call .get on each greenlet to raise any exceptions from it.

Exceptions listed here are raised when either gevent.joinall(<greenlets>, raise_error=True) is called or .get is called on each greenlet, not this function itself.

Parameters:
  • remote_file (str) – remote filepath to copy to local host
  • local_file (str) – local filepath on local host to copy file to
  • recurse (bool) – whether or not to recurse
  • suffix_separator (str) – (Optional) Separator string between filename and host, defaults to _. For example, for a local_file value of myfile and default separator the resulting filename will be myfile_myhost for the file from host myhost. suffix_separator has no meaning if copy_args is provided
  • copy_args (tuple or list) – (Optional) Format remote_file and local_file strings with per-host arguments in copy_args. copy_args length must equal length of host list - pssh.exceptions.HostArgumentError is raised otherwise
Return type:

list(gevent.Greenlet) of greenlets for remote copy commands
Raises:

ValueError when a directory is supplied to local_file and recurse is not set
Raises:

pssh.exceptions.HostArgumentError on number of per-host copy arguments not equal to number of hosts
Raises:

IOError on I/O errors writing files
Raises:

OSError on OS errors like permission denied

Note

Local directories in local_file that do not exist will be created as long as permissions allow.

Note

File names will be de-duplicated by appending the hostname to the filepath separated by suffix_separator.

disconnect()
finished(output=None)

Check if commands have finished without blocking.

Parameters:output (list(HostOutput)) – (Optional) Output to check if finished. Defaults to get_last_output
Return type:bool
get_last_output(cmds=None)

Get output for last commands executed by run_command.

Parameters:cmds (list(gevent.Greenlet)) – Commands to get output for. Defaults to client.cmds
Return type:dict or list
join(output=None, consume_output=False, timeout=None)

Wait until all remote commands in output have finished. Does not block other commands from running in parallel.

Parameters:
  • output (HostOutput objects) – Output of commands to join on
  • consume_output (bool) – Whether or not join should consume output buffers. Output buffers will be empty after join if set to True. Must be set to True to allow host logger to log output on call to join when host logger has been enabled.
  • timeout (float) – Timeout in seconds if all remote commands are not yet finished. This function’s timeout is for all commands in total and will therefor be affected by pool size and total number of concurrent commands in self.pool. Since self.timeout is passed onto each individual SSH session it is not used for any parallel functions like run_command or join.
Raises:

pssh.exceptions.Timeout on timeout requested and reached with commands still running.
Return type:

None
join_shells(shells, timeout=None)

Wait for running commands to complete and close shells.

Parameters:
Raises:

pssh.exceptions.Timeout on timeout requested and reached with commands still running.
open_shell(encoding='utf-8', read_timeout=None)

Open interactive shells on all hosts.

Parameters:
  • encoding (str) – Encoding to use for command string and shell output.
  • read_timeout (float) – Seconds before reading from output times out.
Returns:

Opened shells for each of self.hosts, in order.
Return type:

list(pssh.clients.native.base.single.InteractiveShell)
run_command(command, user=None, stop_on_errors=True, host_args=None, use_pty=False, shell=None, encoding='utf-8', *args, **kwargs)
run_shell_commands(shells, commands)

Run command(s) on shells.

Parameters:
hosts