Some Grouper properties files can have overlays so that only the changes from the defaults of the config files need to be tracked in the institution specific config file. Also, configs can be centrally stored on a server across multiple webapps or standalone Grouper applications. There can be a default configuration file, and an override file so that only the changes from the default can be tracked in the overlay.
Using this approach to Configuration Files can make Grouper more easily deployable across environments, and more easily upgradable.
This is available in Grouper v2.2+ for the following config files:
- grouper.properties
- grouper.hibernate.properties
- grouper-loader.properties
- grouper-ui.properties
- grouper-ws.properties
- grouper.client.properties
- subject.properties
In the future we can add this feature to other config files as well.
How it works
Each of the properties files has a base file, and a config file. For example, there is a grouper.base.properties, and a grouper.properties. Both of these are located on the classpath in the default package. e.g. WEB-INF/classes/grouper.base.properties and WEB-INF/classes/grouper.properties. Generally all the default settings will be located in the base config file, and only the things that are overridden are in the grouper.properties. This is a change in v2.2+ since before that all properties are in the grouper.properties, and the example file was used just to show what configs are possible.
Specify the hierarchy
If you do not want to use the base and the overlay in the classpath, you can specify which files are used for the properties. This must be specified in the base or config file. Each config file has its own key for this hierarchy, but it is listed in the base config file. Here is an example for the grouper.properties. Note, it is recommended to include the classpath base properties, though it is up to you. You can specify config files by classpath or file location.
Edge cases
If you override a key with an empty value, that will blank out that config value
Config file reloading
You can specify the number of seconds that the config file will be checked to see if there are differences. This is not a trivial check, so it is recommended not to be more often than every 60 seconds. If -1 is specified, then it will never be checked. If it is 0 then it will be checked each time a config param is referenced. Note, this is another properties that must be specified in the base or config file, it cannot be put in other places specified in the hierarchy. Here is an example for grouper.properties:
grouper.config.secondsBetweenUpdateChecks = 60
Expression language in property values
You can specify the property key in such a way that you can have value include expression language scriplets. The class edu.internet2.middleware.grouperClient.util.GcElUtilsSafe can be referenced as "elUtils". To specify a key as EL, append this suffix to the config key: .elConfig
To use a custom class in the EL, Write a class with a static method, compile, put in a jar on the classpath. There should be a default constructor in the class. Refer to the fully qualified class in EL:
package edu.internet2.middleware.grouperClient.config;
/**
* some test class for EL
* @author mchyzer
*
*/
public class SomeTestElClass {
/**
* some method for EL
* @param a
* @param b
* @return the result
*/
public static String someMethod(String a, String b) {
return a + b + " something else";
}
}
EL in a properties file:
some.config.2.elConfig = ${edu.internet2.middleware.grouperClient.config.SomeTestElClass.someMethod('start', ' middle')}
This will result in the value (for key: some.config.2): start middle something else
Migrating
Note: subject.properties configures where the sources.xml is
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