Ansible Reference: Module Utilities

This page documents utilities intended to be helpful when writing Ansible modules in Python.

AnsibleModule

To use this functionality, include from ansible.module_utils.basic import AnsibleModule in your module.

class ansible.module_utils.basic.AnsibleModule(argument_spec, bypass_checks=False, no_log=False, mutually_exclusive=None, required_together=None, required_one_of=None, add_file_common_args=False, supports_check_mode=False, required_if=None, required_by=None)

Common code for quickly building an ansible module in Python (although you can write modules with anything that can return JSON).

See Developing modules for a general introduction and Ansible module architecture for more detailed explanation.

add_path_info(kwargs): for results that are files, supplement the info about the file in the return path with stats about the file path.

atomic_move(src, dest, unsafe_writes=False, keep_dest_attrs=True): atomically move src to dest, copying attributes from dest, returns true on success it uses os.rename to ensure this as it is an atomic operation, rest of the function is to work around limitations, corner cases and ensure selinux context is saved if possible

backup_local(fn): make a date-marked backup of the specified file, return True or False on success or failure

boolean(arg): Convert the argument to a boolean

digest_from_file(filename, algorithm): Return hex digest of local file for a digest_method specified by name, or None if file is not present.

exit_json(**kwargs) → NoReturn: return from the module, without error

fail_json(msg, **kwargs) → NoReturn: return from the module, with an error message

find_mount_point(path)

Takes a path and returns its mount point

Parameters:: path – a string type with a filesystem path
Returns:: the path to the mount point as a text type

get_bin_path(arg, required=False, opt_dirs=None)

Find system executable in PATH.

Parameters:

arg – The executable to find.
required – if the executable is not found and required is True, fail_json
opt_dirs – optional list of directories to search in addition to PATH

Returns:

if found return full path; otherwise return original arg, unless ‘warning’ then return None

Raises:

Sysexit: if arg is not found and required=True (via fail_json)

is_executable(path)

is the given path executable?

Parameters:: path – The path of the file to check.

Limitations:

Does not account for FSACLs.
Most times we really want to know “Can the current user execute this file”. This function does not tell us that, only if any execute bit is set.

is_special_selinux_path(path): Returns a tuple containing (True, selinux_context) if the given path is on a NFS or other ‘special’ fs mount point, otherwise the return will be (False, None).

load_file_common_arguments(params, path=None)

many modules deal with files, this encapsulates common options that the file module accepts such that it is directly available to all modules and they can share code.

Allows to overwrite the path/dest module argument by providing path.

md5(filename)

Return MD5 hex digest of local file using digest_from_file().

Do not use this function unless you have no other choice for:

Optional backwards compatibility
Compatibility with a third party protocol

This function will not work on systems complying with FIPS-140-2.

Most uses of this function can use the module.sha1 function instead.

preserved_copy(src, dest): Copy a file with preserved ownership, permissions and context

run_command(args, check_rc=False, close_fds=True, executable=None, data=None, binary_data=False, path_prefix=None, cwd=None, use_unsafe_shell=False, prompt_regex=None, environ_update=None, umask=None, encoding='utf-8', errors='surrogate_or_strict', expand_user_and_vars=True, pass_fds=None, before_communicate_callback=None, ignore_invalid_cwd=True, handle_exceptions=True)

Execute a command, returns rc, stdout, and stderr.

The mechanism of this method for reading stdout and stderr differs from that of CPython subprocess.Popen.communicate, in that this method will stop reading once the spawned command has exited and stdout and stderr have been consumed, as opposed to waiting until stdout/stderr are closed. This can be an important distinction, when taken into account that a forked or backgrounded process may hold stdout or stderr open for longer than the spawned command.

Parameters:: args – is the command to run * If args is a list, the command will be run with shell=False. * If args is a string and use_unsafe_shell=False it will split args to a list and run with shell=False * If args is a string and use_unsafe_shell=True it runs with shell=True.
Kw check_rc:: Whether to call fail_json in case of non zero RC. Default False
Kw close_fds:: See documentation for subprocess.Popen(). Default True
Kw executable:: See documentation for subprocess.Popen(). Default None
Kw data:: If given, information to write to the stdin of the command
Kw binary_data:: If False, append a newline to the data. Default False
Kw path_prefix:: If given, additional path to find the command in. This adds to the PATH environment variable so helper commands in the same directory can also be found
Kw cwd:: If given, working directory to run the command inside
Kw use_unsafe_shell:: See args parameter. Default False
Kw prompt_regex:: Regex string (not a compiled regex) which can be used to detect prompts in the stdout which would otherwise cause the execution to hang (especially if no input data is specified)
Kw environ_update:: dictionary to update environ variables with
Kw umask:: Umask to be used when running the command. Default None
Kw encoding:: Since we return native strings, on python3 we need to know the encoding to use to transform from bytes to text. If you want to always get bytes back, use encoding=None. The default is “utf-8”. This does not affect transformation of strings given as args.
Kw errors:: Since we return native strings, on python3 we need to transform stdout and stderr from bytes to text. If the bytes are undecodable in the encoding specified, then use this error handler to deal with them. The default is surrogate_or_strict which means that the bytes will be decoded using the surrogateescape error handler if available (available on all python3 versions we support) otherwise a UnicodeError traceback will be raised. This does not affect transformations of strings given as args.
Kw expand_user_and_vars:: When use_unsafe_shell=False this argument dictates whether ~ is expanded in paths and environment variables are expanded before running the command. When True a string such as $SHELL will be expanded regardless of escaping. When False and use_unsafe_shell=False no path or variable expansion will be done.
Kw pass_fds:: When running on Python 3 this argument dictates which file descriptors should be passed to an underlying Popen constructor. On Python 2, this will set close_fds to False.
Kw before_communicate_callback:: This function will be called after Popen object will be created but before communicating to the process. (Popen object will be passed to callback as a first argument)
Kw ignore_invalid_cwd:: This flag indicates whether an invalid cwd (non-existent or not a directory) should be ignored or should raise an exception.
Kw handle_exceptions:: This flag indicates whether an exception will be handled inline and issue a failed_json or if the caller should handle it.
Returns:: A 3-tuple of return code (integer), stdout (native string), and stderr (native string). On python2, stdout and stderr are both byte strings. On python3, stdout and stderr are text strings converted according to the encoding and errors parameters. If you want byte strings on python3, use encoding=None to turn decoding to text off.

sha1(filename): Return SHA1 hex digest of local file using digest_from_file().

sha256(filename): Return SHA-256 hex digest of local file using digest_from_file().

Basic

To use this functionality, include import ansible.module_utils.basic in your module.

ansible.module_utils.basic.get_all_subclasses(cls): Deprecated: Use ansible.module_utils.common._utils.get_all_subclasses instead

ansible.module_utils.basic.get_platform()

Deprecated Use platform.system() directly.

Returns:: Name of the platform the module is running on in a native string

Returns a native string that labels the platform (“Linux”, “Solaris”, etc). Currently, this is the result of calling platform.system().

ansible.module_utils.basic.heuristic_log_sanitize(data, no_log_values=None): Remove strings that look like passwords from log messages

ansible.module_utils.basic.load_platform_subclass(cls, *args, **kwargs): Deprecated: Use ansible.module_utils.common.sys_info.get_platform_subclass instead

Argument Spec

Classes and functions for validating parameters against an argument spec.

ArgumentSpecValidator

class ansible.module_utils.common.arg_spec.ArgumentSpecValidator(argument_spec, mutually_exclusive=None, required_together=None, required_one_of=None, required_if=None, required_by=None)

Argument spec validation class

Creates a validator based on the argument_spec that can be used to validate a number of parameters using the validate() method.

Parameters:

argument_spec (dict[str, dict]) – Specification of valid parameters and their type. May include nested argument specs.
mutually_exclusive (list[str] or list[list[str]]) – List or list of lists of terms that should not be provided together.
required_together (list[list[str]]) – List of lists of terms that are required together.
required_one_of (list[list[str]]) – List of lists of terms, one of which in each list is required.
required_if (list) – List of lists of [parameter, value, [parameters]] where one of [parameters] is required if parameter == value.
required_by (dict[str, list[str]]) – Dictionary of parameter names that contain a list of parameters required by each key in the dictionary.

validate(parameters, *args, **kwargs)

Validate parameters against argument spec.

Error messages in the ValidationResult may contain no_log values and should be sanitized with sanitize_keys() before logging or displaying.

Parameters:

parameters (dict[str, dict]) – Parameters to validate against the argument spec

Returns:

ValidationResult containing validated parameters.

Simple Example:

argument_spec = {
    'name': {'type': 'str'},
    'age': {'type': 'int'},
}

parameters = {
    'name': 'bo',
    'age': '42',
}

validator = ArgumentSpecValidator(argument_spec)
result = validator.validate(parameters)

if result.error_messages:
    sys.exit("Validation failed: {0}".format(", ".join(result.error_messages))

valid_params = result.validated_parameters

ValidationResult

class ansible.module_utils.common.arg_spec.ValidationResult(parameters)

Result of argument spec validation.

This is the object returned by ArgumentSpecValidator.validate() containing the validated parameters and any errors.

Parameters:: parameters (dict) – Terms to be validated and coerced to the correct type.

errors: AnsibleValidationErrorMultiple containing all AnsibleValidationError objects if there were any failures during validation.

property validated_parameters: Validated and coerced parameters.

property unsupported_parameters: set of unsupported parameter names.

property error_messages: list of all error messages from each exception in errors.

Parameters

ansible.module_utils.common.parameters.DEFAULT_TYPE_VALIDATORS: dict of type names, such as 'str', and the default function used to check that type, check_type_str() in this case.

ansible.module_utils.common.parameters.env_fallback(*args, **kwargs): Load value from environment variable

ansible.module_utils.common.parameters.remove_values(value, no_log_strings)

Remove strings in no_log_strings from value.

If value is a container type, then remove a lot more.

Use of deferred_removals exists, rather than a pure recursive solution, because of the potential to hit the maximum recursion depth when dealing with large amounts of data (see issue #24560).

ansible.module_utils.common.parameters.sanitize_keys(obj, no_log_strings, ignore_keys=frozenset({}))

Sanitize the keys in a container object by removing no_log values from key names.

This is a companion function to the remove_values() function. Similar to that function, we make use of deferred_removals to avoid hitting maximum recursion depth in cases of large data structures.

Parameters:

obj – The container object to sanitize. Non-container objects are returned unmodified.
no_log_strings – A set of string values we do not want logged.
ignore_keys – A set of string values of keys to not sanitize.

Returns:

An object with sanitized keys.

Validation

Standalone functions for validating various parameter types.

ansible.module_utils.common.validation.check_missing_parameters(parameters, required_parameters=None)

This is for checking for required params when we can not check via argspec because we need more information than is simply given in the argspec.

Raises TypeError if any required parameters are missing

Parameters:

parameters – Dictionary of parameters
required_parameters – List of parameters to look for in the given parameters.

Returns:

Empty list or raises TypeError if the check fails.

ansible.module_utils.common.validation.check_mutually_exclusive(terms, parameters, options_context=None)

Check mutually exclusive terms against argument parameters

Accepts a single list or list of lists that are groups of terms that should be mutually exclusive with one another

Parameters:

terms – List of mutually exclusive parameters
parameters – Dictionary of parameters
options_context – List of strings of parent key names if terms are in a sub spec.

Returns:

Empty list or raises TypeError if the check fails.

ansible.module_utils.common.validation.check_required_arguments(argument_spec, parameters, options_context=None)

Check all parameters in argument_spec and return a list of parameters that are required but not present in parameters.

Raises TypeError if the check fails

Parameters:

argument_spec – Argument spec dictionary containing all parameters and their specification
parameters – Dictionary of parameters
options_context – List of strings of parent key names if argument_spec are in a sub spec.

Returns:

Empty list or raises TypeError if the check fails.

ansible.module_utils.common.validation.check_required_by(requirements, parameters, options_context=None)

For each key in requirements, check the corresponding list to see if they exist in parameters.

Accepts a single string or list of values for each key.

Parameters:

requirements – Dictionary of requirements
parameters – Dictionary of parameters
options_context – List of strings of parent key names if requirements are in a sub spec.

Returns:

Empty dictionary or raises TypeError if the check fails.

ansible.module_utils.common.validation.check_required_if(requirements, parameters, options_context=None)

Check parameters that are conditionally required

Raises TypeError if the check fails

Parameters:: requirements – List of lists specifying a parameter, value, parameters required when the given parameter is the specified value, and optionally a boolean indicating any or all parameters are required.
Example:

required_if=[
    ['state', 'present', ('path',), True],
    ['someint', 99, ('bool_param', 'string_param')],
]

Parameters:

parameters – Dictionary of parameters
options_context – List of strings of parent key names if requirements are in a sub spec.

Returns:

Empty list or raises TypeError if the check fails. The results attribute of the exception contains a list of dictionaries. Each dictionary is the result of evaluating each item in requirements. Each return dictionary contains the following keys:

key missing:

List of parameters that are required but missing

key requires:

’any’ or ‘all’

key parameter:

Parameter name that has the requirement

key value:

Original value of the parameter

key requirements:

Original required parameters

Example:

[
    {
        'parameter': 'someint',
        'value': 99
        'requirements': ('bool_param', 'string_param'),
        'missing': ['string_param'],
        'requires': 'all',
    }
]

ansible.module_utils.common.validation.check_required_one_of(terms, parameters, options_context=None)

Check each list of terms to ensure at least one exists in the given module parameters

Accepts a list of lists or tuples

Parameters:

terms – List of lists of terms to check. For each list of terms, at least one is required.
parameters – Dictionary of parameters
options_context – List of strings of parent key names if terms are in a sub spec.

Returns:

Empty list or raises TypeError if the check fails.

ansible.module_utils.common.validation.check_required_together(terms, parameters, options_context=None)

Check each list of terms to ensure every parameter in each list exists in the given parameters.

Accepts a list of lists or tuples.

Parameters:

terms – List of lists of terms to check. Each list should include parameters that are all required when at least one is specified in the parameters.
parameters – Dictionary of parameters
options_context – List of strings of parent key names if terms are in a sub spec.

Returns:

Empty list or raises TypeError if the check fails.

ansible.module_utils.common.validation.check_type_bits(value)

Convert a human-readable string bits value to bits in integer.

Example: check_type_bits('1Mb') returns integer 1048576.

Raises TypeError if unable to convert the value.

ansible.module_utils.common.validation.check_type_bool(value)

Verify that the value is a bool or convert it to a bool and return it.

Raises TypeError if unable to convert to a bool

Parameters:: value – String, int, or float to convert to bool. Valid booleans include: ‘1’, ‘on’, 1, ‘0’, 0, ‘n’, ‘f’, ‘false’, ‘true’, ‘y’, ‘t’, ‘yes’, ‘no’, ‘off’
Returns:: Boolean True or False

ansible.module_utils.common.validation.check_type_bytes(value)

Convert a human-readable string value to bytes

Raises TypeError if unable to convert the value

ansible.module_utils.common.validation.check_type_dict(value)

Verify that value is a dict or convert it to a dict and return it.

Raises TypeError if unable to convert to a dict

Parameters:: value – Dict or string to convert to a dict. Accepts k1=v2, k2=v2 or k1=v2 k2=v2.
Returns:: value converted to a dictionary

ansible.module_utils.common.validation.check_type_float(value)

Verify that value is a float or convert it to a float and return it

Raises TypeError if unable to convert to a float

Parameters:: value – float, int, str, or bytes to verify or convert and return.
Returns:: float of given value.

ansible.module_utils.common.validation.check_type_int(value)

Verify that the value is an integer and return it or convert the value to an integer and return it

Raises TypeError if unable to convert to an int

Parameters:: value – String or int to convert of verify
Returns:: int of given value

ansible.module_utils.common.validation.check_type_jsonarg(value)

Return a jsonified string. Sometimes the controller turns a json string into a dict/list so transform it back into json here

Raises TypeError if unable to convert the value

ansible.module_utils.common.validation.check_type_list(value)

Verify that the value is a list or convert to a list

A comma separated string will be split into a list. Raises a TypeError if unable to convert to a list.

Parameters:: value – Value to validate or convert to a list
Returns:: Original value if it is already a list, single item list if a float, int, or string without commas, or a multi-item list if a comma-delimited string.

ansible.module_utils.common.validation.check_type_path(value): Verify the provided value is a string or convert it to a string, then return the expanded path

ansible.module_utils.common.validation.check_type_raw(value): Returns the raw value

ansible.module_utils.common.validation.check_type_str(value, allow_conversion=True, param=None, prefix='')

Verify that the value is a string or convert to a string.

Since unexpected changes can sometimes happen when converting to a string, allow_conversion controls whether or not the value will be converted or a TypeError will be raised if the value is not a string and would be converted

Parameters:

value – Value to validate or convert to a string
allow_conversion – Whether to convert the string and return it or raise a TypeError

Returns:

Original value if it is a string, the value converted to a string if allow_conversion=True, or raises a TypeError if allow_conversion=False.

ansible.module_utils.common.validation.count_terms(terms, parameters)

Count the number of occurrences of a key in a given dictionary

Parameters:

terms – String or iterable of values to check
parameters – Dictionary of parameters

Returns:

An integer that is the number of occurrences of the terms values in the provided dictionary.

Errors

exception ansible.module_utils.errors.AnsibleFallbackNotFound: Fallback validator was not found

exception ansible.module_utils.errors.AnsibleValidationError(message)

Single argument spec validation error

error_message: The error message passed in when the exception was raised.

property msg: The error message passed in when the exception was raised.

exception ansible.module_utils.errors.AnsibleValidationErrorMultiple(errors=None)

Multiple argument spec validation errors

errors: list of AnsibleValidationError objects

property msg: The first message from the first error in errors.

property messages: list of each error message in errors.

append(error)

Append a new error to self.errors.

Only AnsibleValidationError should be added.

extend(errors): Append each item in errors to self.errors. Only AnsibleValidationError should be added.

exception ansible.module_utils.errors.AliasError(message): Error handling aliases

exception ansible.module_utils.errors.ArgumentTypeError(message): Error with parameter type

exception ansible.module_utils.errors.ArgumentValueError(message): Error with parameter value

exception ansible.module_utils.errors.DeprecationError(message): Error processing parameter deprecations

exception ansible.module_utils.errors.ElementError(message): Error when validating elements

exception ansible.module_utils.errors.MutuallyExclusiveError(message): Mutually exclusive parameters were supplied

exception ansible.module_utils.errors.NoLogError(message): Error converting no_log values

exception ansible.module_utils.errors.RequiredByError(message): Error with parameters that are required by other parameters

exception ansible.module_utils.errors.RequiredDefaultError(message): A required parameter was assigned a default value

exception ansible.module_utils.errors.RequiredError(message): Missing a required parameter

exception ansible.module_utils.errors.RequiredIfError(message): Error with conditionally required parameters

exception ansible.module_utils.errors.RequiredOneOfError(message): Error with parameters where at least one is required

exception ansible.module_utils.errors.RequiredTogetherError(message): Error with parameters that are required together

exception ansible.module_utils.errors.SubParameterTypeError(message): Incorrect type for subparameter

exception ansible.module_utils.errors.UnsupportedError(message): Unsupported parameters were supplied