COT.cli module

CLI entry point for the Common OVF Tool (COT) suite.

Functions

formatter

Create formatter for log output.

Classes

CLI	Command-line user interface for COT.

class CLI(terminal_width=None)

Bases: COT.ui_shared.UI

Command-line user interface for COT.

confirm	Prompt user to confirm the requested operation.
create_parser	Create parser object for global cot command.
create_subparsers	Populate the CLI sub-parsers for all known submodules.
fill_examples	Pretty-print a set of usage examples.
fill_usage	Pretty-print a list of usage strings for a COT subcommand.
get_input	Prompt the user to enter a string.
get_password	Get password string from the user.
main	Main worker function for COT when invoked from the CLI.
parse_args	Parse the given CLI arguments into a namespace object.
run	Parse the given CLI args then run.
set_verbosity	Enable logging and/or change the logging verbosity level.
terminal_width	The width of the terminal in columns.

__init__(terminal_width=None)

Create CLI handler instance.

Parameters:terminal_width (int) – (optional) Set the terminal width for this CLI, independent of the actual terminal in use.

add_subparser(title, parent=None, aliases=None, lookup_prefix='', **kwargs)

Create a subparser under the specified parent.

Parameters:

• title (str) – Canonical keyword for this subparser
• parent (object) – Subparser grouping object returned by ArgumentParser.add_subparsers()
• aliases (list) – Aliases for title. Only used in Python 3.x.
• lookup_prefix (str) – String to prepend to title and each alias in aliases for lookup purposes.
• kwargs (dict) – Passed through to parent.add_parser()

Returns:

object – Subparser object

static args_to_dict(args)

Convert args to a dict and perform any needed cleanup.

Parameters:args (argparse.Namespace) – Namespace from parse_args(). Returns:dict – Dictionary of arg to value

confirm(prompt)

Prompt user to confirm the requested operation.

Auto-accepts if force is set to True.

Parameters:prompt (str) – Message to prompt the user with Returns:bool – True (user accepts) or False (user declines)

create_parser()

Create parser object for global cot command.

Includes a number of globally applicable CLI options.

create_subparsers()

Populate the CLI sub-parsers for all known submodules.

Creates an instance of each COTGenericSubmodule subclass, then calls create_subparser() for each.

fill_examples(example_list)

Pretty-print a set of usage examples.

Parameters:example_list (list) – List of (description, CLI example) tuples. Returns:str – Concatenation of examples, each wrapped appropriately to the terminal_width() value. CLI examples will be wrapped with backslashes and a hanging indent.

Examples

>>> print(CLI(68).fill_examples([
...  ("Deploy to vSphere/ESXi server 192.0.2.100 with credentials"
...   " admin/admin, creating a VM named 'test_vm' from foo.ova.",
...   'cot deploy foo.ova esxi 192.0.2.100 -u admin -p admin'
...   ' -n test_vm'),
...  ("Deploy to vSphere/ESXi server 192.0.2.100, with username"
...   " admin (prompting the user to input a password at runtime),"
...   " creating a VM based on profile '1CPU-2.5GB' in foo.ova.",
...   'cot deploy foo.ova esxi 192.0.2.100 -u admin -c 1CPU-2.5GB')
... ]))
Examples:
  Deploy to vSphere/ESXi server 192.0.2.100 with credentials
  admin/admin, creating a VM named 'test_vm' from foo.ova.

    cot deploy foo.ova esxi 192.0.2.100 -u admin -p admin \
        -n test_vm

  Deploy to vSphere/ESXi server 192.0.2.100, with username admin
  (prompting the user to input a password at runtime), creating a
  VM based on profile '1CPU-2.5GB' in foo.ova.

    cot deploy foo.ova esxi 192.0.2.100 -u admin -c 1CPU-2.5GB

fill_usage(subcommand, usage_list)

Pretty-print a list of usage strings for a COT subcommand.

Automatically prepends a cot subcommand --help usage string to the provided list.

Parameters:

• subcommand (str) – Subcommand name/keyword
• usage_list (list) – List of usage strings for this subcommand.

Returns:

string – All usage strings, each appropriately wrapped to the terminal_width() value.

Examples

>>> print(CLI(50).fill_usage('add-file',
...       ["FILE PACKAGE [-o OUTPUT] [-f FILE_ID]"]))

  cot add-file --help
  cot <opts> add-file FILE PACKAGE [-o OUTPUT]
                      [-f FILE_ID]

get_input(prompt, default_value)

Prompt the user to enter a string.

Auto-inputs the default_value if force is set to True.

Parameters:

• prompt (str) – Message to prompt the user with
• default_value (str) – Default value to input if the user simply hits Enter without entering a value, or if force.

Returns:

str – Input value

get_password(username, host)

Get password string from the user.

Parameters:

• username (str) – Username the password is associated with
• host (str) – Host the password is associated with

Raises:

InvalidInputError – if force is True (as there is no “default” password value)

Returns:

str – Password string

main(args)

Main worker function for COT when invoked from the CLI.

• Calls set_verbosity() with the appropriate verbosity level derived from the args.
• Looks up the appropriate COTGenericSubmodule instance corresponding to the subcommand that was invoked.
• Converts args to a dict and calls set_value() for each arg/value in the dict.
• Calls run() followed by finished().
• Catches various exceptions and handles them appropriately.

Parameters:args (argparse.Namespace) – Parser namespace object returned from parse_args(). Returns:int – Exit code for the COT executable.

• 0 on successful completion
• 1 on runtime error
• 2 on input error (parser error, InvalidInputError, etc.)

parse_args(argv)

Parse the given CLI arguments into a namespace object.

Parameters:argv (list) – List of CLI arguments, not including argv0 Returns:argparse.Namespace – Parser namespace object

run(argv)

Parse the given CLI args then run.

Calls parse_args() followed by main().

Parameters:argv (list) – The CLI argv value (not including argv[0]) Returns:int – Return code from main()

static set_instance_attributes(arg_dict)

Set attributes of the instance based on the given arg_dict.

Parameters:arg_dict (dict) – Dictionary of (attribute, value). Raises:InvalidInputError – if attributes are not validly set.

set_verbosity(level)

Enable logging and/or change the logging verbosity level.

Will call formatter() and associate the resulting formatter with logging.

Parameters:level (int) – Logging level as defined by logging

terminal_width

The width of the terminal in columns.

formatter(verbosity=20)

Create formatter for log output.

We offer different (more verbose) formatting when debugging is enabled, hence this need.

Parameters:verbosity (int) – Logging level as defined by logging. Returns:colorlog.ColoredFormatter – Formatter object to use with logging.

main()

Launch COT from the CLI.