[WIP] Add UID and GID to the user object from user package

[ishank011]

Currently, the UID and GID for users need to be read from the local system which requires local users to be present. This change retrieves that information from the user and auth packages and adds methods to retrieve it.

Closes #964

[ishank011]

@labkode the PR is ready for review. Some initial testing is done, working on deploying it for further tests.

One thing which I'm not very sure about is this part. Whenever we stat for resources, EOS returns the UID, which we encode as "uid:xyz" since we have no way of resolving it at the fs level. This is done at the gateway layer to get the user ID back from the UID using this method. I modified the GetUser method to return the user based on UID passed as opaque.

Please let me know if this is fine or if we should switch to some other approach.

[labkode]

@labkode the PR is ready for review. Some initial testing is done, working on deploying it for further tests.

One thing which I'm not very sure about is this part. Whenever we stat for resources, EOS returns the UID, which we encode as "uid:xyz" since we have no way of resolving it at the fs level. This is done at the gateway layer to get the user ID back from the UID using this method. I modified the GetUser method to return the user based on UID passed as opaque.

Please let me know if this is fine or if we should switch to some other approach.

What about having the EOS driver calling the userprovider grpc endpoint to resolve the uid to username and then pass it to the upper layers? This approach will avoid the uid: hack but will add a dependency to the userprovider grpc service. What do you think? Also @butonic @refs @IljaN ?

[ishank011]

@labkode yes that could be an approach as well. Would save a lot of the changes I had to do at the upper levels.

[labkode]

@ishank011 let's try then that approach, the drivers that need extra user information for implementing their logic they can connect to the gateway and request for specific user metadata.

Can you adapt that part to contact the Gateway API instead?

[ishank011]

@labkode Cool, I'll make the change. Thanks!

[ishank011]

Alternate approach #995 merged.