This PR refactors object layer handling such
that upon failure in sub-system initialization
server reaches a stage of safe-mode operation
wherein only certain API operations are enabled
and available.
This allows for fixing many scenarios such as
- incorrect configuration in vault, etcd,
notification targets
- missing files, incomplete config migrations
unable to read encrypted content etc
- any other issues related to notification,
policies, lifecycle etc
This PR adds code to appropriately handle versioning issues
that come up quite constantly across our API changes. Currently
we were also routing our requests wrong which sort of made it
harder to write a consistent error handling code to appropriately
reject or honor requests.
This PR potentially fixes issues
- old mc is used against new minio release which is incompatible
returns an appropriate for client action.
- any older servers talking to each other, report appropriate error
- incompatible peer servers should report error and reject the calls
with appropriate error
- Supports migrating only when the credential ENVs are set,
so any FS mode deployments which do not have ENVs set will
continue to remain as is.
- Credential ENVs can be rotated using MINIO_ACCESS_KEY_OLD
and MINIO_SECRET_KEY_OLD envs, in such scenarios it allowed
to rotate the encrypted content to a new admin key.