ABRT configuration service

[jfilak]

Develop a service which allows administrators to configure ABRT from various systems (e.g. OpenLMI, see the discussion at #750).

Requirements:

• D-Bus service
• easily extensible (because of the plug-in architecture)

Proposal:
The configuration is still stored in configuration files placed on the local file system and the configuration service provides a single entry point to the configuration.
A configuration domain (all configuration options of a plug-in - it could be several configuration files) is represent by a single D-Bus interface consisting only from properties. An each property of the configuration interface corresponds to an option from a configuration file. The configuration service loads the configuration interfaces from XML files placed in D-Bus interfaces directory (usually '/usr/share/dbus-1/interfaces/'). However, the configuration service loads only files whose name are prefixed by 'com.redhat.problems.configuration'. The configuration service registers a D-Bus object for each loaded configuration interface and the path of a configuration object is taken from the node's XML attribute 'name'. All configuration objects implements the default configuration interface which defines 'SetDefault(s)' method which resets an option's value to default value. The default configuration interface is provided by the configuration service.
The interface's XML definition must contain a pair of annotation elements which specify these files:

• a working configuration file to read the configuration and where the changes are saved
• a default configuration file to read the default values

The service listens on the system bus and only authorized users can read/write property values (option values). The authorization is requested instantly for all actions (e.g. get a property's value).

[jfilak]

The configuration service has been introduced by commit 8e70962

[jfilak]

Done