refactor minio.credentials

[balamurugana]

Depends on Minio.get_assume_role_creds() in #900

[Praveenrajmani]

Just few minor nits - Otherwise LGTM

[Praveenrajmani]

LGTM

[vadmeste]

@balamurugana could you explain what the API change done in this PR ?

Also could you make sure that examples are updated ?

[balamurugana]

@balamurugana could you explain what the API change done in this PR ?

Below is the design change I proposed earlier and this PR is a refactor with this design.

from abc import ABCMeta, abstractmethod
from datetime import datetime


class Value():
    """
    Denotes credential values such as access key, secret key and session token.
    """
    def init(self, access_key, secret_key, session_token):
        self.access_key = access_key
        self.secret_key = secret_key
        self.session_token = session_token


class Provider():
    """Credential retriever."""
    metaclass = ABCMeta

    @abstractmethod
    def retrieve(self) -> (Value, datetime):
        """Retrieve credential value and its expiry."""


class Credentials():
    def __init__(self, provider):
        self._provider = provider
        self._value = None
        self._validity = None

    def get(self, force=False):
        if (
                not self._value or
                (self._validity and self._validity < datetime.utcnow()) or
                force
        ):
            self._value, self._validity = self._provider.retrieva()
        return self._value

Also could you make sure that examples are updated ?

Let me check once again.

[Praveenrajmani]

LGTM

[vadmeste]

Few comments, LGTM otherwise. Not tested yet

[vadmeste]

Maybe here we should return the last encountered ValueError exception.. so at least the user can see a more self explaining error.

[balamurugana]

Done

[vadmeste]

Maybe it is enough if we can credentials in this form:

  Static(access_key, secret_key, session_token),

and create a Value instance inside Static init() function.

Let's review the API with @abperiasamy one last time.

[balamurugana]

I have changed to Static(access_key, secret_key, session_token=None, expiry=None)

[vadmeste]

Well, this is a breaking change, we should not forget about mentioning it when we release minio-py

[balamurugana]

Yes. I think we are covering in #902

[vadmeste]

LGTM & tested, we probably need to write all possible breaking things in a document before we release

[kannappanr]

ping @Praveenrajmani