Improved concurrency handling in `pull` about ssm-diff HOT 2 OPEN

If it isn't obvious, this request requires a local file that stores the remote values from the last time pull or init was run. I'd probably create a file like <filename>.orig right next to <filename>.yml.

from ssm-diff.

As I dig deeper, I think the following case will result in unwanted behavior in the current implementation:

• init with a remote like {'a': {'b': {'c': 'd', 'x': 'y'}}}
• delete the remote key /a/b/x (on SSM)
• pull (with or without force)
• apply

In both cases, the pull will treat the local a/b/x key as "added". The key will be retained and restored to SSM when apply is run. Most users will probably want the tool to recognize the remote delete and update the local file accordingly.

from ssm-diff.