Support environment properties that would have worked in 1.5

[philwebb]

The stricter environment variable property rules in 2.0 might catch people out and it would be really nice if we could warn users that a property that previously worked now will not.

One example of this is in Spring Cloud stream. They previously would set the varaible SPRING_CLOUD_STREAM_KAFKA_BINDER_ZK_NODES. In 2.0 this needs to be SPRING_CLOUD_STREAM_KAFKA_BINDER_ZKNODES.

[philwebb]

I've absolutely no idea how we can do this. Perhaps we can update ConfigurationPropertySource so that if it gets called with getConfigurationProperty("zknodes") it checks to see if there are any matches excluding underscores and issues a warning.

[snicoll]

You mean SPRING_CLOUD_STREAM_KAFKA_BINDER_ZKNODES right?

[philwebb]

Edited 🤦‍♂️

[philwebb]

Thinking some more about this I think it should be possible to support the SPRING_CLOUD_STREAM_KAFKA_BINDER_ZK_NODES style in addition to SPRING_CLOUD_STREAM_KAFKA_BINDER_ZKNODES. I think we should still promote the first style in documentation etc.

[philwebb]

/cc @dsyer @markfisher