Fix infinite loop on cloudwatchlogs GetLogEventsPages

[johanneswuerbach]

Cloudwatch log event responses always include the next token even when there are no more results and pagination will never terminate.

More details aws/aws-sdk-ruby#712

This replicates a similar fix applied to the ruby aws-sdk aws/aws-sdk-ruby#730

[jasdel]

Thanks for creating this PR @johanneswuerbach, was this a recent issue that started to fail? I noticed the Ruby issue is back in 2015 so i'm curious if this is a new regression with CloudWatchLogs, or a bug that has always existed.

Is there a specific condition where this error occurs with CloudWatchLogs, does this error occur for any pagination of the CloudWatchLogs GetLogEvents API?

[johanneswuerbach]

I just started to use this API and noticed the never ending pagination with any kind of provided input.

The current ruby sdk also still has the last page condition changes added in 2015, so I would say those changes are still valid https://github.com/aws/aws-sdk-ruby/blob/4edc8bc84b8994b9db497ecd5ad229348252bb37/gems/aws-sdk-core/lib/aws-sdk-core/pager.rb#L42-L44

[johanneswuerbach]

Any additional details I can provide @jasdel?

An example requiring a workaround can now be seen here https://github.com/virtual-kubelet/virtual-kubelet/blob/b4cb8099681118f8049234f12328f7a73c4b1a50/providers/aws/fargate/cluster.go#L330-L344

//cc @ofiliz

[xibz]

Hello @johanneswuerbach, I've went ahead and expanding on your PR to allow for users to opt into this functionality in addition to fixing the paginator for the service. Please see #1945! And thank you again for taking the time to do this. I'll go ahead and close this PR.