mirror of
https://github.com/coredns/coredns.git
synced 2025-11-02 02:03:13 -05:00
acbcad7b4e
* reload: use OnRestart
Close the listener on OnRestart for health and metrics so the default
setup function can setup the listener when the plugin is "starting up".
Lightly test with some SIGUSR1-ing. Also checked the reload plugin with
this, seems fine:
.com.:1043
.:1043
2018/04/20 15:01:25 [INFO] CoreDNS-1.1.1
2018/04/20 15:01:25 [INFO] linux/amd64, go1.10,
CoreDNS-1.1.1
linux/amd64, go1.10,
2018/04/20 15:01:25 [INFO] Running configuration MD5 = aa8b3f03946fb60546ca1f725d482714
2018/04/20 15:02:01 [INFO] Reloading
2018/04/20 15:02:01 [INFO] Running configuration MD5 = b34a96d99e01db4015a892212560155f
2018/04/20 15:02:01 [INFO] Reloading complete
^C2018/04/20 15:02:06 [INFO] SIGINT: Shutting down
With this corefile:
.com {
proxy . 127.0.0.1:53
prometheus :9054
whoami
reload
}
. {
proxy . 127.0.0.1:53
prometheus :9054
whoami
reload
}
The prometheus port was 9053, changed that to 54 so reload would pick it
up.
From a cursory look it seems this also fixes:
Fixes #1604 #1618 #1686 #1492
* At least make it test
* Use onfinalshutdown
* reload: add reload test
This test #1604 adn right now fails.
* Address review comments
* Add bug section explaining things a bit
* compile tests
* Fix tests
* fixes
* slightly less crazy
* try to make prometheus setup less confusing
* Use ephermal port for test
* Don't use the listener
* These are shared between goroutines, just use the boolean in the main
structure.
* Fix text in the reload README,
* Set addr to TODO once stopping it
* Morph fturb's comment into test, to test reload and scrape health and
metric endpoint
95 lines
1.7 KiB
Go
95 lines
1.7 KiB
Go
// Package health implements an HTTP handler that responds to health checks.
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package health
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import (
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"io"
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"net"
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"net/http"
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"sync"
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"time"
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"github.com/coredns/coredns/plugin/pkg/log"
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)
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// Health implements healthchecks by polling plugins.
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type health struct {
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Addr string
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lameduck time.Duration
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ln net.Listener
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nlSetup bool
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mux *http.ServeMux
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// A slice of Healthers that the health plugin will poll every second for their health status.
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h []Healther
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sync.RWMutex
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ok bool // ok is the global boolean indicating an all healthy plugin stack
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stop chan bool
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pollstop chan bool
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}
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// newHealth returns a new initialized health.
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func newHealth(addr string) *health {
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return &health{Addr: addr, stop: make(chan bool), pollstop: make(chan bool)}
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}
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func (h *health) OnStartup() error {
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if h.Addr == "" {
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h.Addr = defAddr
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}
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ln, err := net.Listen("tcp", h.Addr)
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if err != nil {
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return err
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}
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h.ln = ln
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h.mux = http.NewServeMux()
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h.nlSetup = true
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h.mux.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
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if h.Ok() {
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w.WriteHeader(http.StatusOK)
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io.WriteString(w, ok)
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return
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}
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w.WriteHeader(http.StatusServiceUnavailable)
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})
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go func() { http.Serve(h.ln, h.mux) }()
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go func() { h.overloaded() }()
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return nil
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}
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func (h *health) OnRestart() error { return h.OnFinalShutdown() }
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func (h *health) OnFinalShutdown() error {
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if !h.nlSetup {
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return nil
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}
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// Stop polling plugins
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h.pollstop <- true
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// NACK health
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h.SetOk(false)
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if h.lameduck > 0 {
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log.Infof("Going into lameduck mode for %s", h.lameduck)
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time.Sleep(h.lameduck)
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}
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h.ln.Close()
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h.stop <- true
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h.nlSetup = false
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return nil
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}
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const (
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ok = "OK"
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defAddr = ":8080"
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path = "/health"
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)
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