From a4f43ca65377643e96ec91108effe7321a6b0d6c Mon Sep 17 00:00:00 2001
From: Justin Venus <justin.venus@gmail.com>
Date: Wed, 4 Feb 2026 19:12:43 -0600
Subject: [PATCH] Add support for Rename and Create events in inotify file
 watching

Fixes #204

Previously, the inotify watcher only handled Write and Remove events.
This caused issues when editors like vim perform atomic writes (which
generate Rename events) or when files are atomically swapped via
directory operations.

This change:
- Adds explicit handling for Rename events by re-adding the watch
  after rename operations (ensuring continued monitoring when files
  are replaced)
- Adds handling for Create events (which occur with atomic writes
  from some editors)
- Improves error handling for Remove events to be non-fatal (important
  for Kubernetes configmap/secret mounts)
- Maintains watching the specific file path rather than the directory
  or inode, as preferred by users

The solution watches the file path and handles all event types that
can occur during atomic file operations, making it robust for both
editor-based edits and atomic swap scenarios without requiring
directory-level watching.
---
 integration/reload.bats | 37 +++++++++++++++++++++++++++++++++++++
 main.go                 | 31 +++++++++++++++++++++++--------
 2 files changed, 60 insertions(+), 8 deletions(-)

diff --git a/integration/reload.bats b/integration/reload.bats
index e8219d7..5110199 100755
--- a/integration/reload.bats
+++ b/integration/reload.bats
@@ -85,3 +85,40 @@ grep_test_file() {
   kill -s TERM "$PID"
   wait
 }
+
+@test "if inotify is enabled it handles RENAME events (vim-style atomic writes)" {
+  echo '* * * * * * * echo a > "$TEST_FILE"' > "$CRONTAB_FILE"
+
+  "${BATS_TEST_DIRNAME}/../supercronic" -inotify "$CRONTAB_FILE" 3>&- &
+  PID="$!"
+
+  wait_for grep_test_file a
+
+  # Simulate vim-style atomic write: create temp file, write to it, rename over original
+  TEMP_FILE="${CRONTAB_FILE}.tmp"
+  echo '* * * * * * * echo b > "$TEST_FILE"' > "$TEMP_FILE"
+  mv "$TEMP_FILE" "$CRONTAB_FILE"
+
+  wait_for grep_test_file b
+
+  kill -s TERM "$PID"
+  wait
+}
+
+@test "if inotify is enabled it handles CREATE events (file recreation)" {
+  echo '* * * * * * * echo a > "$TEST_FILE"' > "$CRONTAB_FILE"
+
+  "${BATS_TEST_DIRNAME}/../supercronic" -inotify "$CRONTAB_FILE" 3>&- &
+  PID="$!"
+
+  wait_for grep_test_file a
+
+  # Simulate Create event: remove file, then create new one at same path
+  rm "$CRONTAB_FILE"
+  echo '* * * * * * * echo b > "$TEST_FILE"' > "$CRONTAB_FILE"
+
+  wait_for grep_test_file b
+
+  kill -s TERM "$PID"
+  wait
+}
diff --git a/main.go b/main.go
index 8c6de95..094ac1c 100644
--- a/main.go
+++ b/main.go
@@ -202,19 +202,34 @@ func main() {
 					}
 					logrus.Debugf("event: %v, watch-list: %v", event, watcher.WatchList())
 
-					switch event.Op {
-					case event.Op & fsnotify.Write:
-						logrus.Debug("watched file changed")
+					// Handle any file modification event (Write, Create, Remove, Rename)
+					// Many editors use atomic writes that generate Rename or Create events
+					if event.Op&fsnotify.Write != 0 {
+						logrus.Debug("watched file changed (write)")
 						termChan <- syscall.SIGUSR2
-
-					// workaround for k8s configmap and secret mounts
-					case event.Op & fsnotify.Remove:
-						logrus.Debug("watched file changed")
+						// workaround for k8s configmap and secret mounts
+					} else if event.Op&fsnotify.Create != 0 {
+						logrus.Debug("watched file changed (create)")
+						termChan <- syscall.SIGUSR2
+					} else if event.Op&fsnotify.Rename != 0 {
+						logrus.Debug("watched file changed (rename)")
+						// Re-add watch after rename (file might have been replaced)
 						if err := watcher.Add(crontabFileName); err != nil {
+							logrus.Errorf("failed to re-add watch after rename: %s", err)
 							logrus.Fatal(err)
 							return
+						} else {
+							termChan <- syscall.SIGUSR2
+						}
+					} else if event.Op&fsnotify.Remove != 0 {
+						// workaround for k8s configmap and secret mounts
+						logrus.Debug("watched file changed (remove)")
+						if err := watcher.Add(crontabFileName); err != nil {
+							logrus.Errorf("failed to re-add watch: %s", err)
+							// Don't return/fatal here - just log and continue
+						} else {
+							termChan <- syscall.SIGUSR2
 						}
-						termChan <- syscall.SIGUSR2
 					}
 
 				case err, ok := <-watcher.Errors: