coredns/middleware/pprof/setup.go

package pprof

import (
	"sync"

	"github.com/mholt/caddy"
)

func init() {
	caddy.RegisterPlugin("pprof", caddy.Plugin{
		ServerType: "dns",
		Action:     setup,
	})
}

func setup(c *caddy.Controller) error {
	found := false
	for c.Next() {
		if found {
			return c.Err("pprof can only be specified once")
		}
		if len(c.RemainingArgs()) != 0 {
			return c.ArgErr()
		}
		if c.NextBlock() {
			return c.ArgErr()
		}
		found = true
	}

	handler := &Handler{}
	pprofOnce.Do(func() {
		c.OnStartup(handler.Startup)
		c.OnShutdown(handler.Shutdown)
	})

	return nil
}

var pprofOnce sync.Once