plugin/file: make non-existent file non-fatal (#2955)

* plugin/file: make non-existent file non-fatal

If the zone file being loaded doesn't exist *and* reload is enabled,
just wait the file to pop up in the normal Reload routine.

If reload is set to 0s; we keep this a fatal error on startup. Aslo fix
the ticker in z.Reload(): remove the per second ticks and just use the
reload interval for the ticker.

Brush up the documentation a bit as well.

Fixes: #2951

Signed-off-by: Miek Gieben <miek@miek.nl>

* Stickler and test compile

Signed-off-by: Miek Gieben <miek@miek.nl>

* Remove there too

Signed-off-by: Miek Gieben <miek@miek.nl>

* Cant README test these because zone files dont exist

Signed-off-by: Miek Gieben <miek@miek.nl>

1 files changed, 1 insertions, 11 deletions

diff --git a/plugin/file/reload.go b/plugin/file/reload.go
index e73c5b87d..ce5c81335 100644
--- a/plugin/file/reload.go
+++ b/plugin/file/reload.go
@@ -5,15 +5,12 @@ import (
 	"time"
 )
 
-// TickTime is clock resolution. By default ticks every second. Handler checks if reloadInterval has been reached on every tick.
-var TickTime = 1 * time.Second
-
 // Reload reloads a zone when it is changed on disk. If z.NoReload is true, no reloading will be done.
 func (z *Zone) Reload() error {
 	if z.ReloadInterval == 0 {
 		return nil
 	}
-	tick := time.NewTicker(TickTime)
+	tick := time.NewTicker(z.ReloadInterval)
 
 	go func() {
 
@@ -21,13 +18,6 @@ func (z *Zone) Reload() error {
 			select {
 
 			case <-tick.C:
-				if z.LastReloaded.Add(z.ReloadInterval).After(time.Now()) {
-					//reload interval not reached yet
-					continue
-				}
-				//saving timestamp of last attempted reload
-				z.LastReloaded = time.Now()
-
 				zFile := z.File()
 				reader, err := os.Open(zFile)
 				if err != nil {