config_admin/readme.md - celix - Git at Google

 # Configuration Admin

 ---

 ## Introduction
 The configuration Admin service allows defining and deploying configuration data to bundles.
 When compared to config.properties it adds the option to update configuration data by providing a persisten storage. It also allows changing configuration data at run-time.

 ---

 ## Design

 The config_admin bundle implements the configuration_admin service, the interface to configuration objects and the interface of a managed service. At the moment, the implementation uses a config_admin_factory to generate config_admin services for each bundle that wants to use this service. This is an inheritance of the original design and not needed.
 The configuration data is stored persistently in a subdirectory store of the current bundle directory.
 The filenames have the name of the PID and have an extension pid, e.g. base.device1.pid
 The files contains a list of key/value pairs. At least the following keys need to be present:
 service.bundleLocation
 service.pid

 ---

 ## TODO

 1. Test the configuration of a service_factory
 2. Think about the option to allow remote update of the managed_services
 3. Support configuration of multiple managed services with the same PID. At the moment, only one service is bound to a configuration object.
    To support this the getConfiguration2 function needs to be called with a location NULL according to the spec.

 ---

 ## Usage

 1. Bundle that needs configuration data
    This bundle has to register next to its normal service a managed service that has an update method. This managed service needs to be registered with a properties object that contains the key/value pair service.pid=<PID NAME>.
  Use config_admin_tst/example_test as an example (it is better than example_test2)
 2. Bundle/application that wants to update the configuration data of the system
    This bundle needs to retrieve the running config_admin service. With this service it can retrieve all configuration objects for all known Persistent Identifiers (PIDs). For each PID, get all properites that need to be updated. See config_admin_test for an example.
	# Configuration Admin

	---

	## Introduction
	The configuration Admin service allows defining and deploying configuration data to bundles.
	When compared to config.properties it adds the option to update configuration data by providing a persisten storage. It also allows changing configuration data at run-time.

	---

	## Design

	The config_admin bundle implements the configuration_admin service, the interface to configuration objects and the interface of a managed service. At the moment, the implementation uses a config_admin_factory to generate config_admin services for each bundle that wants to use this service. This is an inheritance of the original design and not needed.
	The configuration data is stored persistently in a subdirectory store of the current bundle directory.
	The filenames have the name of the PID and have an extension pid, e.g. base.device1.pid
	The files contains a list of key/value pairs. At least the following keys need to be present:
	service.bundleLocation
	service.pid

	---

	## TODO

	1. Test the configuration of a service_factory
	2. Think about the option to allow remote update of the managed_services
	3. Support configuration of multiple managed services with the same PID. At the moment, only one service is bound to a configuration object.
	To support this the getConfiguration2 function needs to be called with a location NULL according to the spec.

	---

	## Usage

	1. Bundle that needs configuration data
	This bundle has to register next to its normal service a managed service that has an update method. This managed service needs to be registered with a properties object that contains the key/value pair service.pid=<PID NAME>.
	Use config_admin_tst/example_test as an example (it is better than example_test2)
	2. Bundle/application that wants to update the configuration data of the system
	This bundle needs to retrieve the running config_admin service. With this service it can retrieve all configuration objects for all known Persistent Identifiers (PIDs). For each PID, get all properites that need to be updated. See config_admin_test for an example.