Serialisation: EC2:CreateVPC responses don't always include 'isDefault'.

[fmap]

The following example:

{-# LANGUAGE FlexibleContexts  #-}
{-# LANGUAGE OverloadedStrings #-}

import Control.Lens (view, set)
import Control.Monad.Catch (MonadCatch)
import Control.Monad.Reader.Class (MonadReader)
import Control.Monad.Trans.AWS (Env, envLogger, newLogger, LogLevel(Trace), newEnv, Region(Singapore), Credentials(Discover), runAWST, Env, send)
import Control.Monad.Trans.Resource (MonadResource, runResourceT)
import Data.Functor ((<$>))
import Network.AWS.EC2 (VPC, createVPC, cvrsVPC)
import System.IO (stderr)

mkVPC :: MonadCatch m => MonadResource m => MonadReader Env m => m (Maybe VPC)
mkVPC = view cvrsVPC <$> send (createVPC "10.15.0.0/16") 

main :: IO ()
main = set envLogger <$> newLogger Trace stderr 
   >>= (<$> newEnv Singapore Discover)
   >>= runResourceT . flip runAWST mkVPC
    >> return ()

Currently fails on 'develop' citing:

[Raw Response Body] {
<?xml version="1.0" encoding="UTF-8"?>
<CreateVpcResponse xmlns="http://ec2.amazonaws.com/doc/2015-04-15/">
    <requestId>1007a025-e9e9-469d-b3e4-e8e2d6e79130</requestId>
    <vpc>
        <vpcId>vpc-86ac03e3</vpcId>
        <state>pending</state>
        <cidrBlock>10.15.0.0/16</cidrBlock>
        <dhcpOptionsId>dopt-e7339b8f</dhcpOptionsId>
        <instanceTenancy>default</instanceTenancy>
    </vpc>
</CreateVpcResponse>
}
[SerializeError] {
  service = EC2
  status  = 200 OK
  message = unable to find element "isDefault" in nodes ["vpcId","state","cidrBlock","dhcpOptionsId","instanceTenancy"]
}
*** Exception: SerializeError (SerializeError' {_serializeAbbrev = Abbrev "EC2", _serializeStatus = Status {statusCode = 200, statusMessage = "OK"}, _serializeMessage = "unable to find element \"isDefault\" in nodes [\"vpcId\",\"state\",\"cidrBlock\",\"dhcpOptionsId\",\"instanceTenancy\"]"})

The problem seems to be that the parser of VPC responses expects 'isDefault' to be present in results, while it isn't always(?).

[brendanhay]

Thanks for the example. It appears to have erroneously been added as an override.

[fmap]

Hah, I was just building the generator for fmapfmapfmap@9b4221f. :-)

The override seems to have been introduced here, but it's unclear what motivated it.

Thanks for the quick response! Let's see how it works out.

[brendanhay]

Yes, I also was unable to find reasoning for the addition from commits/memory. Quite alot of the EC2 overrides exist from my own codebases which run against non-standard regions. So it's quite possible they are wrong in the more general sense. #200 exists to try and improve the situation.

[fmap]

Cheers, 🎊.