config

JSON-compliant YAML-based configuration file loading with support for includes, symbol substitution, and live reloading.

Configuration file syntax

The configuration syntax is JSON-compliant YAML. Top-level keys map to smisk.config.config attributes:

smisk:
  autoreload: True
  mvc:
    template_dir: templates/

myapp:
  db_url: "sqlite:///myapp.db"

Use @include to split configuration across files:

@include: base.yaml

Paths can be expanded using glob, so you can include multiple files with a glob pattern:

@include: conf.d/*.yaml

Use @inherit to extend configuration from another file, merging keys recursively.

Logging (the standard library logging module) is configured automatically. Supported handlers: StreamHandler, FileHandler, SysLogHandler. You can also configure a custom Formatter.

logging:
  root:
    level: DEBUG
    handlers: [stderr]
  handlers:
    stderr:
      class: StreamHandler
      stream: ext://sys.stderr

Use ${SYMBOL} in string values to substitute predefined or custom symbols.

Symbol	Description
`${APPDIR}`	Absolute path to the application directory
`${HOSTNAME}`	Current machine hostname

from smisk.config import config
config.load("myapp.yaml")
print(config.myapp.db_url)

smisk.config.config: The global Configuration instance.
smisk.config.config_locations: List of directories searched for configuration files. Defaults include the application directory and /etc.
smisk.config.LOGGING_FORMAT: Default log format string.
smisk.config.LOGGING_DATEFMT: Default log date format string.

smisk.config.configure_logging(): Apply the logging section of the current configuration using Python's logging subsystem.

class smisk.config.Configuration

A lazy-loading configuration object. Attributes are created dynamically from YAML keys.

defaults: A dict of default values applied before loading from files.
default_symbols: Predefined symbol substitutions.
sources: List of loaded source file paths.
filters: List of filter callables applied after loading.
filename_ext: Recognised configuration file extensions. Defaults to [".yaml", ".json"].
logging_key: The key in config used for logging setup. Defaults to "logging".
input_encoding: Character encoding of configuration files. Defaults to "utf-8".
max_include_depth: Maximum nesting depth for @include directives. Defaults to 8.
__init__(): Initialise an empty configuration object.
__call__(): Shorthand for loading the default configuration file.
set_default(key, value): Set a default value for key that is used if the key is not found in any loaded file.
load(filename): Load and apply a configuration file.
loads(string): Load configuration from a string.
reload(): Reload all configuration sources from disk.
reset(): Reset to a blank state, clearing all loaded values.
add_filter(fn): Register a filter callable to be called after each load.