076b8d4fba
Add OnReStartFailed which makes the health plugin stay up if the Corefile is corrupt and we revert to the previous version. Also needs a fix for the channel handling See #2659 Testing it will log the following when restarting with a corrupted Corefile ~~~ 2019-05-04T18:01:59.431Z [INFO] linux/amd64, go1.12.4, CoreDNS-1.5.0 linux/amd64, go1.12.4, [INFO] SIGUSR1: Reloading [INFO] Reloading [ERROR] Restart failed: Corefile:5 - Error during parsing: Unknown directive 'bdhfhdhj' [ERROR] SIGUSR1: starting with listener file descriptors: Corefile:5 - Error during parsing: Unknown directive 'bdhfhdhj' ~~~ After which the curl still works. This also needed a change to reset the channel used for the metrics go-routine which gets closed on shutdown, otherwise you'll see: ~~~ ^C[INFO] SIGINT: Shutting down panic: close of closed channel goroutine 90 [running]: github.com/coredns/coredns/plugin/health.(*health).OnFinalShutdown(0xc000089bc0, 0xc000063d88, 0x4afe6d) ~~~ Signed-off-by: Miek Gieben <miek@miek.nl>
78 lines
1.5 KiB
Go
78 lines
1.5 KiB
Go
package health
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import (
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"fmt"
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"net"
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"time"
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"github.com/coredns/coredns/plugin"
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"github.com/coredns/coredns/plugin/metrics"
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"github.com/mholt/caddy"
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)
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func init() {
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caddy.RegisterPlugin("health", caddy.Plugin{
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ServerType: "dns",
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Action: setup,
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})
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}
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func setup(c *caddy.Controller) error {
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addr, lame, err := parse(c)
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if err != nil {
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return plugin.Error("health", err)
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}
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h := &health{Addr: addr, stop: make(chan bool), lameduck: lame}
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c.OnStartup(func() error {
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metrics.MustRegister(c, HealthDuration)
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return nil
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})
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c.OnStartup(h.OnStartup)
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c.OnRestart(h.OnFinalShutdown)
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c.OnFinalShutdown(h.OnFinalShutdown)
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c.OnRestartFailed(h.OnStartup)
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// Don't do AddPlugin, as health is not *really* a plugin just a separate webserver running.
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return nil
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}
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func parse(c *caddy.Controller) (string, time.Duration, error) {
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addr := ""
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dur := time.Duration(0)
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for c.Next() {
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args := c.RemainingArgs()
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switch len(args) {
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case 0:
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case 1:
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addr = args[0]
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if _, _, e := net.SplitHostPort(addr); e != nil {
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return "", 0, e
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}
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default:
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return "", 0, c.ArgErr()
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}
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for c.NextBlock() {
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switch c.Val() {
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case "lameduck":
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args := c.RemainingArgs()
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if len(args) != 1 {
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return "", 0, c.ArgErr()
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}
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l, err := time.ParseDuration(args[0])
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if err != nil {
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return "", 0, fmt.Errorf("unable to parse lameduck duration value: '%v' : %v", args[0], err)
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}
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dur = l
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default:
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return "", 0, c.ArgErr()
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}
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}
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}
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return addr, dur, nil
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}
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