About external server configuration
- Placeholders in configuration files.
- A plugin that determines the substitution value for placeholder replacement using, in part, a key embedded in the placeholder.
- A Substitutor process that manages the steps in the substitution process.
Configuration placeholders
It is possible to insert placeholders into configuration files that support external configuration. PolicyCenter reads the substitution values from a source external to the application WAR or EAR file and replaces the entire placeholder in the configuration file with the new value.
External configuration provider plugin
Plugin ExternalConfigurationProviderPlugin determines the substitution value of the configuration placeholder. Given information about the placeholder, the plugin returns the substitution value for the placeholder. In the base configuration, PolicyCenter provides a default implementation class for this plugin. However, it is also possible to create your own custom version of this plugin.
Substitutor process
- It parses the configuration files that support externalized configuration and extracts the embedded placeholders from those files.
- It extracts a key from each placeholder that it uses to identify each placeholder.
- It queries the external configuration provider plugin for the substitution value for each placeholder.
- It replaces the placeholder in the configuration file (in its entirety) with the value returned by the plugin.
It is not possible to create your own custom Substitutor process.