Handling of colon in Azure KeyValueStores

[timostrunk]

Hi everyone,
currently minimalkv prohibits using colon ":" in KeyValueStores due to it not being in VALID_KEY_RE_EXTENDED.
Azure Stores would support colons in their path. As far as I know this is currently impossible to read using minimalkv. I.e. if another application writes a file with a colon, you cannot read this file with minimalkv (no expert here though, maybe there is a way to quote this).

I can create a PR to allow for colons only for Azure stores. Would this be ok or is there a decision not to allow this to keep the allowed filenames uniform between different store classes?

[timostrunk]

I made a draft PR here #120

[xhochy]

I would prefer to only allow filename in minimalkv that are supported by a wider range of stores. We can add colons but only if the e.g. also work in the other major cloud object stores.

[timostrunk]

Understood, I will analyze how the other stores are handling colons and post my results in this issue. Please keep the issue open for this, I will close the PR.

[xhochy]

Do you only want to read these keys or also write them?

[timostrunk]

We only need to read these keys. At the moment simply adding the colon to the allowed symbols regexp looks promising. Nothing breaks. The only filesystem I know not accepting colon in the filename would be ntfs.

[xhochy]

I would only be 80% on board adding the colon to allowed characters, but what about turning the key validity check on read from an error into a warning?