Restore DBCluster from S3 snapshot

[AlexLast]

Signed-off-by: Alex Last alexrichardlast@gmail.com

Description of your changes

Fixes #1085

I have:

• Read and followed Crossplane's contribution process.
• Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

• Tested running this build locally
• Tested existing create cluster logic works as expected and creates new DBCluster in AWS
• Tested new restore logic works as expected and restores a new DBCluster in AWS
• Tested observe stages update resource status as expected, when restore is complete

[haarchri]

thanks for implementation - one question regarding our discussion in slack - is creation working without errors ?

[AlexLast]

thanks for implementation - one question regarding our discussion in slack - is creation working without errors ?

@haarchri As expected there is a single error event stating the resource already exists - after preCreate returns and the Create function continues with the usual logic.

Subsequent reconciliations with the observe phase work as expected. Unfortunately as long as preCreate doesn't return an error, Create will continue, and we will get this single error when restoring a DBCluster for the first time.

[haarchri]

Thanks for clarification

[haarchri]

Can you rebase master ? We had a few MRs in RDS area

[haarchri]

Thanks for Implementation