Allow specifying a statsd namespace

[grantr]

It's great that Consul can emit statsd metrics, but without a configurable namespace they aren't as helpful as they could be.

Currently, the namespace varies between consul and consul.<fqdn>. A configuration parameter like statsd_namespace would allow separate consul deployments to each write separate stats.

[ryanuber]

Thanks for the suggestion, marked as an enhancement!

[pwielgolaski]

I looked at the PR that close this issue and it is very misleading.

statsite_prefix The prefix used while writing all telemetry data to statsite. By default, this is set to "consul".

Documentation mention only statsite, but in fact in code this value can be used also for Statsd& DataDog

consul/command/agent/command.go

Line 570 in 5f140f1

metricsConf := metrics.DefaultConfig(config.StatsitePrefix)

I think name should be change or at least description for option