Oslo.config’s primary source of configuration data are plaintext, INI-like style, configuration files. With the addition of backend drivers support, it is possible to store configuration data in different places and with different formats, as long as there exists a proper driver to connect to those external sources and provide a way to fetch configuration values from them.
IMPORTANT: At this point, all backend drivers are only able to provide immutable values. This protects applications and services from having options in external sources mutated when they reload configuration files.
- class oslo_config.sources.ConfigurationSource¶
A configuration source option for oslo.config.
A configuration source is able to fetch configuration values based on a (group, option) key from an external source that supports key-value mapping such as INI files, key-value stores, secret stores, and so on.
- abstract get(group_name, option_name, opt)¶
Return the value of the option from the group.
group_name (str) – Name of the group.
option_name (str) – Name of the option.
opt (Opt) – The option definition.
A tuple (value, location) where value is the option value or oslo_config.sources._NoValue if the (group, option) is not present in the source, and location is a LocationInfo.
- class oslo_config.sources.ConfigurationSourceDriver¶
A backend driver option for oslo.config.
For each group name listed in config_source in the DEFAULT group, a
ConfigurationSourceDriveris responsible for creating one new instance of a
ConfigurationSource. The proper driver class to be used is selected based on the driver option inside each one of the groups listed in config_source and loaded through entry points managed by stevedore using the namespace oslo.config.driver:
[DEFAULT] config_source = source1 config_source = source2 ... [source1] driver = remote_file ... [source2] driver = castellan ...
Each specific driver knows all the available options to properly instatiate a ConfigurationSource using the values comming from the given group in the open_source_from_opt_group() method and is able to generate sample config through the list_options_for_discovery() method.
- abstract list_options_for_discovery()¶
Return the list of options available to configure a new source.
Drivers should advertise all supported options in this method for the purpose of sample generation by oslo-config-generator.
For an example on how to implement this method you can check the remote_file driver at oslo_config.sources._uri.URIConfigurationSourceDriver.
a list of supported options of a ConfigurationSource.
- abstract open_source_from_opt_group(conf, group_name)¶
Return an open configuration source.
Uses group_name to find the configuration settings for the new source and then open the configuration source and return it.
If a source cannot be open, raises an appropriate exception.
conf (ConfigOpts) – The active configuration option handler from which to seek configuration values.
group_name (str) – The configuration option group name where the options for the source are stored.
an instance of a subclass of ConfigurationSource