Issue 553: AWS region should be retrieved considering multiple strategies.

[giova333]

Currently, spring cloud aws uses Ec2MetadataRegionProvider for dynamic region lookup.
However, this solution doesn't work in some cases such #553
We should consider using com.amazonaws.regions.DefaultAwsRegionProviderChain that provides multiple strategies for the region lookup

[maciejwalkowiak]

Thanks @giova333 for PR. I am working on the same issue at exactly same time with a bit different approach as we cannot break backward compatibility at this stage. I appreciate your efforts - give me some time to mark issues as "ideal-to-contribution" and then you could pick them up.

[giova333]

@maciejwalkowiak Sure, no problem.
I think it should be backward compatible as a new RegionProvider is still using ec2 metadata service in addition to env variables, system properties, and profile.
Anyway, take your time to deal with all existing issues

[maciejwalkowiak]

@giova333 this is a change I had in mind #560

[giova333]

@maciejwalkowiak Looks good. The idea to enable DefaultAwsRegionProviderChain via property is great. I think in the major release it should be enabled by default.

[maciejwalkowiak]

Yes I believe so too 👍 Either in 2.3 or 3.0 default chains for both credentials and regions will be used unless static values are provided.