Use entrypoints for known implementations

[TomAugspurger]

Right now, adding a new implementation to the dict of known_implementations requires some coordination between fsspec and the downstream library. This might include the downstream library mutating known_implementations as a side-effect of importing the library.

An alternative is to have fsspec add an entrypoint for implementations, and downstream libraries would add themselves to it.

[martindurant]

This would require other packages outside of fsspec to participate by publishing their protocol entrypoints, but would remove the requirement for them to be either listed in known_implementations in this package or to modify the registry at import time.

[hayesgb]

@martindurant -- Do you want to list either of the abfs:// or adl:// protocols in the fsspec known_implementations, of should I go the route of entrypoints?

[TomAugspurger]

I think those choices are independent. You can register multiple entrypoints within the ffspec group.

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On Mon, Nov 25, 2019 at 7:01 AM Greg Hayes ***@***.***> wrote: @martindurant <https://github.com/martindurant> -- Do you want to list either of the abfs:// or adl:// protocols in the fsspec known_implementations, of should I go the route of entrypoints/ — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#206>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKAOIQNTVD6FW3A55ATVVLQVPECZANCNFSM4JPF6ZWQ> .

[martindurant]

Did you already implement the entrypoints way in fsspec? In that case that should be the way. If not, a PR to fsspec adding the entries to known_implementations.

[TomAugspurger]

No, I haven't implemented it yet. I can later today if there's interest.

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On Mon, Nov 25, 2019 at 8:08 AM Martin Durant ***@***.***> wrote: Did you already implement the entrypoints way in fsspec? In that case that should be the way. If not, a PR to fsspec adding the entries to known_implementations. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#206>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAKAOISVKR7YXQELTZ7EOD3QVPL6ZANCNFSM4JPF6ZWQ> .

[martindurant]

OK, so that's for the future. We want people to be accessing Azure right now, so lets add it into fsspec known_implementations forthwith.