config

class invoke.config.Config(defaults=None, overrides=None, system_prefix=None, user_prefix=None, project_home=None, env_prefix=None, runtime_path=None)

Invoke’s primary configuration handling class.

See Configuration for details on the configuration system this class implements, including the configuration hierarchy. The rest of this class’ documentation assumes familiarity with that document.

Access

Configuration values may be accessed using dict syntax:

config['foo']

or attribute syntax:

config.foo

Nesting works the same way - dict config values are turned into objects which honor both the dictionary protocol and the attribute-access method:

config['foo']['bar']
config.foo.bar

A note about attribute access and methods

This class implements the entire dictionary protocol: methods such as keys, values, items, pop and so forth should all function as they do on regular dicts. It also implements its own methods such as load_collection and clone.

Warning

Accordingly, this means that if you have configuration options sharing names with these methods, you must use dictionary syntax (e.g. myconfig['keys']) to access them.

Individual configuration ‘levels’ and their source locations are stored as ‘private’ attributes (e.g. _defaults, _system_prefix) so fewer names are “taken” from the perspective of attribute access to user config values.

Lifecycle

On initialization, Config will seek out and load various configuration files from disk, then merge the results with other in-memory sources such as defaults and CLI overrides.

Typically, the load_collection and load_shell_env methods are called after initialization - load_collection prior to each task invocation (because collection-level config data may change depending on the task) and load_shell_env as the final step (as it needs the rest of the config to know which env vars are valid to load).

Once users are given a copy of the configuration (usually via their task’s Context argument) all the above loading (& a final merge) has been performed and they are free to modify it as they would any other regular dictionary.

Warning

Calling merge after manually modifying Config objects may overwrite those manual changes, since it overwrites the core config dict with data from per-source attributes like ._defaults or _.user.

__init__(defaults=None, overrides=None, system_prefix=None, user_prefix=None, project_home=None, env_prefix=None, runtime_path=None)

Creates a new config object.

Parameters:
  • defaults (dict) – A dict containing default (lowest level) config data. Default: global_defaults.
  • overrides (dict) – A dict containing override-level config data. Default: {}.
  • system_prefix (str) –

    Path & partial filename for the global config file location. Should include everything but the dot & file extension.

    Default: /etc/invoke (e.g. /etc/invoke.yaml or /etc/invoke.json).

  • user_prefix (str) –

    Like system_prefix but for the per-user config file.

    Default: ~/.invoke (e.g. ~/.invoke.yaml).

  • project_home (str) – Optional directory path location of the currently loaded Collection (as loaded by Loader). When non-empty, will trigger seeking of per-project config files in this location + invoke.(yaml|json|py).
  • env_prefix (str) –

    Environment variable seek prefix; optional, defaults to None.

    When not None, only environment variables beginning with this value will be loaded. If it is set, the keys will have the prefix stripped out before processing, so e.g. env_prefix='INVOKE_' means users must set INVOKE_MYSETTING in the shell to affect the "mysetting" setting.

  • runtime_path (str) –

    Optional file path to a runtime configuration file.

    Used to fill the penultimate slot in the config hierarchy. Should be a full file path to an existing file, not a directory path, or a prefix.

clone()

Return a copy of this configuration object.

The new object will be identical in terms of configured sources and any loaded/merged data, but will be a distinct object with no shared mutable state.

static global_defaults()

Return the core default settings for Invoke.

Generally only for use by Config internals. For descriptions of these values, see Default configuration values.

Subclasses may choose to override this method, calling Config.global_defaults and applying merge_dicts to the result, to add to or modify these values.

load_collection(data)

Update collection-driven config data.

load_collection is intended for use by the core task execution machinery, which is responsible for obtaining per-task collection-driven data. See Collection-based configuration for details.

Note

This method triggers merge after it runs.

load_files()

Load any unloaded/un-searched-for config file sources.

Specifically, any file sources whose _found values are None will be sought and loaded if found; if their _found value is non None (e.g. True or False) they will be skipped. Typically this means this method is idempotent and becomes a no-op after the first run.

Execution of this method does not imply merging; use merge for that.

load_shell_env()

Load values from the shell environment.

load_shell_env is intended for execution late in a Config object’s lifecycle, once all other sources have been merged. Loading from the shell is not terrifically expensive, but must be done at a specific point in time to ensure the “only known config keys are loaded from the env” behavior works correctly.

See Environment variables for details on this design decision and other info re: how environment variables are scanned and loaded.

merge()

Merge all config sources, in order.

Does not imply loading of config files or environment variables; use load_files and/or load_shell_env beforehand instead.

paths

An iterable of all successfully loaded config file paths.

No specific order.

class invoke.config.DataProxy

Helper class implementing nested dict+attr access for Config.

__weakref__

list of weak references to the object (if defined)

invoke.config.merge_dicts(base, updates)

Recursively merge dict updates into dict base (mutating base.)

  • Values which are themselves dicts will be recursed into.
  • Values which are a dict in one input and not a dict in the other input (e.g. if our inputs were {'foo': 5} and {'foo': {'bar': 5}}) are irreconciliable and will generate an exception.