coredns/plugin/autopath/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

87 lines
1.9 KiB
Go

package autopath
import (
"fmt"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/metrics"
"github.com/mholt/caddy"
"github.com/miekg/dns"
)
func init() {
caddy.RegisterPlugin("autopath", caddy.Plugin{
ServerType: "dns",
Action: setup,
})
}
func setup(c *caddy.Controller) error {
ap, mw, err := autoPathParse(c)
if err != nil {
return plugin.Error("autopath", err)
}
c.OnStartup(func() error {
metrics.MustRegister(c, autoPathCount)
return nil
})
// Do this in OnStartup, so all plugin has been initialized.
c.OnStartup(func() error {
m := dnsserver.GetConfig(c).Handler(mw)
if m == nil {
return nil
}
if x, ok := m.(AutoPather); ok {
ap.searchFunc = x.AutoPath
} else {
return plugin.Error("autopath", fmt.Errorf("%s does not implement the AutoPather interface", mw))
}
return nil
})
dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
ap.Next = next
return ap
})
return nil
}
func autoPathParse(c *caddy.Controller) (*AutoPath, string, error) {
ap := &AutoPath{}
mw := ""
for c.Next() {
zoneAndresolv := c.RemainingArgs()
if len(zoneAndresolv) < 1 {
return ap, "", fmt.Errorf("no resolv-conf specified")
}
resolv := zoneAndresolv[len(zoneAndresolv)-1]
if resolv[0] == '@' {
mw = resolv[1:]
} else {
// assume file on disk
rc, err := dns.ClientConfigFromFile(resolv)
if err != nil {
return ap, "", fmt.Errorf("failed to parse %q: %v", resolv, err)
}
ap.search = rc.Search
plugin.Zones(ap.search).Normalize()
ap.search = append(ap.search, "") // sentinel value as demanded.
}
ap.Zones = zoneAndresolv[:len(zoneAndresolv)-1]
if len(ap.Zones) == 0 {
ap.Zones = make([]string, len(c.ServerBlockKeys))
copy(ap.Zones, c.ServerBlockKeys)
}
for i, str := range ap.Zones {
ap.Zones[i] = plugin.Host(str).Normalize()
}
}
return ap, mw, nil
}