AutoscalingGroups with a TargetGroup set are not parsed correctly

[msiuts]

There is an issue with parsing the response of DescribeAutoscalingGroups.

We have 52 ASGs. Two of them have one TargetGroup associated.

When we get all the ASGs via fog with something like Fog::AWS[:auto_scaling].groups the two ASGs with the assigned TargetGroups are not parsed correctly and appear two times in the list with different attributes not set (nil) for example the ARN or the Id.

Here are some steps that show the issue:

irb(main):005:0* require 'fog/aws'
=> true
irb(main):006:0> asg_ids = Fog::AWS[:auto_scaling].groups.all.size
=> 54
irb(main):007:0> asg_ids = Fog::AWS[:auto_scaling].groups.all.select{ |g| g.arn}.size
=> 52
irb(main):008:0> asg_ids = Fog::AWS[:auto_scaling].groups.all.select{ |g| g.id}.size
=> 52

The issue seems to be in the parser which does not recognize the TargetGroups element and closes the parsed ASG too early and starting the next one.

I think it would be easy to provide support for TargetGroups and we are going to provide a PR for this.

It should be discussed how the parser (DescribeAutoScalingGroups) can be more robust for new elements, especially since the AWS-API version does not seem to be pinned.

[geemus]

I think we do pin the version actually: https://github.com/fog/fog-aws/blob/master/lib/fog/aws/compute.rb#L462

Unfortunately, the changelog from AWS sometimes leaves something to be desired (so we occasionally miss things like this). I think the parsers usually do a pretty good job of being resilient (at least in terms of continuing to work as expected, but just lacking new info), but we definitely have some outliers like this. Hopefully it is the exception rather than the rule, but certainly worth keeping an eye on.

Going to go ahead and close this in favor of the PR, which looks like it has the particular issue in hand.