Add support for read-only JDBC URI

[otheriault]

First off, I really like the simplicity of this new CfEnv project for parsing Cloud Foundry VCAP_SERVICES and injecting properties into spring-boot for auto-configuration. I think it has a lot of potential!

I have been trying to figure out an easy way to support an additional parameter in the credentials property of a given CfService. My specific use case is to support a read-only URI that could be used as a secondary data source, similar to what is mentioned here: https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#howto-two-datasources.

In the best case, the jdbc-url for the secondary datasource would be provided in the service-broker/user-provided-service directly. In the worse case, the jdbc-url would have to be generated by a JdbcUrlCreator from a series of credentials.read-* properties (url/uri, host, port, username, password...) in the service-broker/user-provided-service.

Since spring-framework has no pre-defined properties for this specific use case, I'm not sure this is something that should be explicitly covered by this library. However, at the same time I feel that this library could be more accommodating to custom service-broker(s)/user-provided-service(s) credentials properties. As such, I think it's worth exploring how to support this use case through some sort of extensibility mechanism.

I am looking forward to the feedback on this and am willing to become a contributor to this project.

[pivotal-david-osullivan]

Hi @otheriault, revisiting this issue, is this still an active requirement?