Dynamic topic configuration

I have lots of metric data coming into my Influx installation from a very heterogeneous environment. To correctly route alerts, I want to add a global ``contact`` Telegraf tag to every metric line and have Kapacitor route any relevant alerts to the e-mail defined in that tag. Because it's a very heterogeneous environment, there are lots of users -- statically defining topics for all of these users/groups would be very time-consuming and burdensome.

I don't *think* it's possible to do this with Kapacitor currently, but I'm not sure. Is it possible to configure aspects of a topic via tags on the data being sent to that topic?

Start by reviewing Kapacitor's topic routing and alert configuration, then trace how Telegraf tags are carried into metric data. Determine whether a topic can use a tag value for dynamic email routing; done means documenting the supported behavior or defining and validating the required configuration change.

Written by the indexing model from the issue text.