AutoScalingReplacingUpdatePolicy.hs

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE TupleSections #-}

-- | To specify how AWS CloudFormation handles replacing updates for an Auto
-- Scaling group, use the AutoScalingReplacingUpdate policy.

module Stratosphere.ResourceAttributes.AutoScalingReplacingUpdatePolicy where

import Stratosphere.ResourceImports


-- | Full data type definition for AutoScalingReplacingUpdatePolicy. See
-- 'autoScalingReplacingUpdatePolicy' for a more convenient constructor.
data AutoScalingReplacingUpdatePolicy =
  AutoScalingReplacingUpdatePolicy
  { _autoScalingReplacingUpdatePolicyWillReplace :: Maybe (Val Bool)
  } deriving (Show, Eq)

instance ToJSON AutoScalingReplacingUpdatePolicy where
  toJSON AutoScalingReplacingUpdatePolicy{..} =
    object $
    catMaybes
    [ fmap (("WillReplace",) . toJSON . fmap Bool') _autoScalingReplacingUpdatePolicyWillReplace
    ]

instance FromJSON AutoScalingReplacingUpdatePolicy where
  parseJSON (Object obj) =
    AutoScalingReplacingUpdatePolicy <$>
      fmap (fmap (fmap unBool')) (obj .:? "WillReplace")
  parseJSON _ = mempty

-- | Constructor for 'AutoScalingReplacingUpdatePolicy' containing required fields
-- as arguments.
autoScalingReplacingUpdatePolicy
  :: AutoScalingReplacingUpdatePolicy
autoScalingReplacingUpdatePolicy  =
  AutoScalingReplacingUpdatePolicy
  { _autoScalingReplacingUpdatePolicyWillReplace = Nothing
  }

-- | Specifies whether an Auto Scaling group and the instances it contains are
-- replaced during an update. During replacement, AWS CloudFormation retains
-- the old group until it finishes creating the new one. This allows AWS
-- CloudFormation to roll back to the old Auto Scaling group if the update
-- doesn't succeed. While AWS CloudFormation creates the new group, it doesn't
-- detach or attach any instances. After creating the new Auto Scaling group,
-- AWS CloudFormation removes the old Auto Scaling group during the cleanup
-- process. If the update doesn't succeed, AWS CloudFormation removes the new
-- Auto Scaling group.
asrupWillReplace :: Lens' AutoScalingReplacingUpdatePolicy (Maybe (Val Bool))
asrupWillReplace = lens _autoScalingReplacingUpdatePolicyWillReplace (\s a -> s { _autoScalingReplacingUpdatePolicyWillReplace = a })