When externalizing grails app configurations for multiple environments I want to ensure values are provided for all the required/expected properties.  So I wrote a plugin to help.

Validating Expected and Required Properties

Simply add something like this to Config.groovy

validate  {
    required = [ "a", "b", "c" ]
    expected = [ "p":123, "d":"foobar", "q":"/dev/null" ]
}

Then (usually in BootStrap.groovy ) to set defaults for missing expected properties callgrailsApplication.config.validateExpectedProperties()To check for required properties callgrailsApplication.config.validateRequiredProperties()A ConfigurationException will be thrown when required properties are missing.

The validate.expected and validate.required data can be specified at lower levels too…

grails {
    mongo {
        validate {
            required = [
                "grails.mongo.host",
                "grails.mongo.databaseName"
            ]
            expected = [
                "grails.mongo.port": 27017,
                "grails.mongo.bucket": "project"
            ]
        }
    }
}

This way you can validate portions of the config by callinggrailsApplication.config.grails.mongo.validateExpectedProperties()and so on.

Validating Existence of External Files

The ConfigUtils.validateExternalFiles method will check that a list of files does exist.  Use it like this in Config.groovy.

grails.config.locations << "file:${userHome}/.emacs"
grails.config.locations < "file:${userHome}/.grails/${appName}-config.groovy"
ConfigUtils.validateExternalFiles(grails.config.locations)

A ConfigurationException will be thrown when any of the files does not exist.

Resources

• Grails plugin http://grails.org/plugin/validate-config.
• Sample app https://github.com/onetribeyoyo/validate-config/tree/master/example.