Since AssumeRole API was introduced we have a wrong route
match which results in certain clients failing to upload objects
using multipart because, multipart POST conflicts with STS POST
AssumeRole API.
Write a proper matcher function which verifies the route more
appropriately such that both can co-exist.
Deprecate the use of Admin Peers concept and migrate all peer
communication to Notification subsystem. This finally allows
for a common subsystem for all peer notification in case of
distributed server deployments.
This PR introduces two new features
- AWS STS compatible STS API named AssumeRoleWithClientGrants
```
POST /?Action=AssumeRoleWithClientGrants&Token=<jwt>
```
This API endpoint returns temporary access credentials, access
tokens signature types supported by this API
- RSA keys
- ECDSA keys
Fetches the required public key from the JWKS endpoints, provides
them as rsa or ecdsa public keys.
- External policy engine support, in this case OPA policy engine
- Credentials are stored on disks
