[Hawkular-dev] About configuration

Hi everyone, Yesterday Lukas asked on IRC if there was a discussion about configuration. AFAIK, there wasn't, hence I'm sharing how we support configuration in metrics. # Metrics REST server The REST server runs on top of Wildfly. Configuration is a set of key/value pairs (configuration properties) defined by the following sources, in order of precedence: * system properties (-Dkey=value) * external java.util.Properties file, which path is defined by the metrics.conf system property; by default, <user.home>/.metrics.conf is used (if it exists) * internal java.util.Properties file (META-INF/metrics.conf) The rationale behind is that the system should be able to: 1. start with reasonable defaults 2. switch to another configuration easily # pTrans pTrans is different because it's a standalone application, so it's much easier to follow the daemon configuration habits. pTrans takes a path to a properties configuration file as a program argument. This argument is mandatory. # Configuration file format. metrics started with properties file and I think it's fine. But if we feel the need for a more structured format, we should pick something which can be easily parsed by a variety of programming languages, especially languages widely used for administration (Python and Ruby). Regards, Thomas