coredns/plugin/proxy/setup.go
Francois Tur f9bdd382dd Ensure Re-register of metrics variables after a reload (#2080)
* - ensure plugins that use prometheus.MustRegister, re-register after reload
- removing once.Do on the startup function was simplest way to do it.

* - fix underscored names (advice of bot)

* - tune existing UT for reload, and add a test verifying failing reload does not prevent correct registering for metrics

* - ensure different ports for tests that can run in same time ..
2018-09-19 02:11:24 -07:00

53 lines
1.1 KiB
Go

package proxy
import (
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/metrics"
clog "github.com/coredns/coredns/plugin/pkg/log"
"github.com/mholt/caddy"
)
var log = clog.NewWithPlugin("proxy")
func init() {
caddy.RegisterPlugin("proxy", caddy.Plugin{
ServerType: "dns",
Action: setup,
})
}
func setup(c *caddy.Controller) error {
upstreams, err := NewStaticUpstreams(&c.Dispenser)
if err != nil {
return plugin.Error("proxy", err)
}
t := dnsserver.GetConfig(c).Handler("trace")
P := &Proxy{Trace: t}
dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
P.Next = next
P.Upstreams = &upstreams
return P
})
c.OnStartup(func() error {
metrics.MustRegister(c, RequestCount, RequestDuration)
return nil
})
for i := range upstreams {
u := upstreams[i]
c.OnStartup(func() error {
return u.Exchanger().OnStartup(P)
})
c.OnShutdown(func() error {
return u.Exchanger().OnShutdown(P)
})
// Register shutdown handlers.
c.OnShutdown(u.Stop)
}
return nil
}