Elasticsearch Metrics containing '[=]' Characters not being properly whitelisted

[jamesalanthompson]

We've come across an issue when trying to delivery metrics generated by the elasticsearch collectd plugin to cloudwatch via collectd-cloudwatch.

I suspect it may have something to do with the characters contained within the naming used:

elasticsearch-clustername-gauge-indices[index=indexname].total.docs.count

The metrics show as expected in the blocked_metrics, but on adding them in that format, or with a wildcard I'm so far unable to see the metrics arriving in cloudwatch. All other metrics are seemingly fine.