* plugin/health: add lameduck mode
Add a way to configure lameduck more, i.e. set health to false, stop
polling plugins. Then wait for a duration before shutting down. As the
health middleware is configured early on in the plugin list, it will
hold up all other shutdown, meaning we still answer queries.
* Add New
* More tests
* golint
* remove confusing text
* plugin/health: add 'overloaded metrics'
Query our on health endpoint and record (and export as a metric) the
time it takes. The Get has a 5s timeout, that, when reached, will set
the metric duration to 5s. The actually call "I'm I overloaded" is left
to an external entity.
* README
* golint and govet
* and the tests
Switched health and autopath plugin to allow any plugins to be used instead
of a hardcoded list. I did not switch federation over since it wasn't
obvious that anything other than kubernetes could be used with it.
Fixes#1291
* Rename middleware to plugin
first pass; mostly used 'sed', few spots where I manually changed
text.
This still builds a coredns binary.
* fmt error
* Rename AddMiddleware to AddPlugin
* Readd AddMiddleware to remain backwards compat
