Question

我尝试访问存储桶中的密钥，但我没有权限，尽管我为密钥做了。为了能够get_key('this/is/my_key')，我需要桶对象：

conn = boto.connect_s3(key, secret_key)
my_bucket = conn.get_bucket('a_bucket')

收益S3ResponseError: S3ResponseError: 403 Forbidden。

另一方面，以下作品

my_bucket = boto.s3.bucket.Bucket(conn, 'a_bucket')
my_bucket.get_key('this/is/my_key')

问题：创建对象Bucket和使用get_bucket方法有什么区别？检查docu我只看到检查验证。还有什么吗？

Answer 1

validate=True中的验证（get_bucket默认值）在调用时检查存在桶。由于您无权访问存储桶，因此拒绝了您的请求（403）。在另一种情况下，类实例化似乎没有进行验证，因此get_key方法按预期工作。

Answer 2

get_bucket（）需要s3：listObject权限

get_key（）只需要s3：GetObject权限

因此，以下行不会创建任何桶。

{-# language GeneralizedNewtypeDeriving #-}
{-# language DeriveFunctor #-}
{-# language FlexibleInstances #-}
{-# language MultiParamTypeClasses #-}
{-# language RankNTypes #-}
{-# language TypeFamilies #-}
{-# language UndecidableInstances #-}
{-# language ScopedTypeVariables #-}
module Eve.Internal.Actions
( AppF(..)
, ActionT(..)
, AppT

, execApp
, liftAction
) where

import Control.Monad.State
import Control.Monad.Trans.Free
import Control.Lens

-- | An 'App' has the same base and zoomed values.
type AppT s m a = ActionT s s m a

-- | A Free Functor for storing lifted App actions.
newtype AppF base m next = LiftAction (StateT base m next)
    deriving (Functor, Applicative)

-- | Base Action type. Allows paramaterization over application state,
-- zoomed state and underlying monad.
newtype ActionT base zoomed m a = ActionT
    { getAction :: FreeT (AppF base m) (StateT zoomed m) a
    } deriving (Functor, Applicative, Monad, MonadIO, MonadState zoomed)

instance Monad n => MonadFree (AppF base n) (ActionT base zoomed n) where
    wrap (LiftAction act) = join . ActionT . liftF . LiftAction $ act

instance MonadTrans (ActionT base zoomed) where
    lift = ActionT . lift . lift

-- | Helper method to run FreeTs.
unLift :: Monad m => FreeT (AppF base m) (StateT base m) a -> StateT base m a
unLift m = do
    step <- runFreeT m
    case step of
        Pure a -> return a
        Free (LiftAction next) -> next >>= unLift

-- | Allows 'zoom'ing 'Action's.
type instance Zoomed (ActionT base zoomed m) =
    Zoomed (FreeT (AppF base m) (StateT zoomed m))
instance Monad m => Zoom (ActionT base s m) (ActionT base t m) s t where
    zoom l (ActionT action) = ActionT $ zoom l action

-- | Given a 'Lens' or 'Traversal' or something similar from "Control.Lens"
-- which focuses the state (t) of an 'Action' from a base state (s),
-- this will convert @Action t a -> Action s a@.
--
-- Given a lens @HasStates s => Lens' s t@ it can also convert 
-- @Action t a -> App a@
runAction :: Zoom m n s t => LensLike' (Zoomed m c) t s -> m c -> n c
runAction = zoom

-- | Allows you to run an 'App' or 'AppM' inside of an 'Action' or 'ActionM'
liftAction :: Monad m => AppT base m a -> ActionT base zoomed m a
liftAction = liftF .  LiftAction . unLift . getAction

-- | Runs an application and returns the value and state.
runApp :: Monad m => base -> AppT base m a -> m (a, base)
runApp baseState = flip runStateT baseState . unLift . getAction

-- | Runs an application and returns the resulting state.
execApp :: Monad m => base -> AppT base m a -> m base
execApp baseState = fmap snd . runApp baseState

它只是创建一个指向存储桶的python对象类。只要您没有执行任何与存储桶相关的任务，就没有错误。如果你可以没有错误地执行get_key（），那就意味着你获得了对桶的s3：GetObject权限。

boto s3 Bucket与get_bucket

2 个答案: