[Enhancement] Authentication feature of ShardingProxy

[tristaZero]

Introduction

This feature is the same as the authentication of MySQL or PostgreSQL. ShardingProxy has to do access control when users login in.

Three key points need to clarify

• This issue is an enhancement feature for the current Authentication module
• All users configured in server.yaml of ShardingProxy still work and are seen as system users.
• We will leverage the access-control power of different Databases

Tasks

Load

• Get users from DB and Configuration
• Load the privilege information from databases
• Merge privileges by rules
• Refactor API and user configuration
• Different implement of loading privileges from Oracle/Pg/SQLServer

Refresh

• ShardingProxy supports create user SQL, which will be pushed down to databases
• ShardingProxy supports grant SQL, which will be pushed down to database
• ShardingProxy supports revoke SQL, which will be pushed down to databases
• Refresh users and reload privileges for the SQLs above

Check

Login

• Get the IP or hostname once users login
• Get the user name, password once users login
• Check users' name and password
• SQL check interface and framework
• SQL checking for use DB and show DB
• SQL checking for other SQLs

Tests

• PrivilegeBuilder
• PrivilegeMerger
• PrivilegeLoader
• MetadataRefreshEngine