Fix error handling in tail methods

tail.go

@@ -8,6 +8,7 @@ import (
 	"time"
 
 	"github.com/hpcloud/tail"
+	"gopkg.in/tomb.v1"
 )
 
 func tailFile(ctx context.Context, file string, poll bool, dest *os.File) {
@@ -49,7 +50,7 @@ func tailFile(ctx context.Context, file string, poll bool, dest *os.File) {
 			return
 		// get the next log line and echo it out
 		case line := <-t.Lines:
-			if t.Err() != nil {
+			if t.Err() != nil && t.Err() != tomb.ErrStillAlive {
 				log.Printf("Warning: unable to tail %s: %s", file, t.Err())
 				errCount++
 				if errCount > 30 {
@@ -58,6 +59,13 @@ func tailFile(ctx context.Context, file string, poll bool, dest *os.File) {
 				time.Sleep(2 * time.Second) // Sleep for 2 seconds before retrying
 			} else if line == nil {
 				return
+			} else if line.Err != nil {
+				log.Printf("Warning: unable to tail %s: %s", file, t.Err())
+				errCount++
+				if errCount > 30 {
+					log.Fatalf("Logged %d consecutive errors while tailing. Exiting", errCount)
+				}
+				time.Sleep(2 * time.Second) // Sleep for 2 seconds before retrying
 			} else {
 				fmt.Fprintln(dest, line.Text)
 				errCount = 0 // Zero the error count