mirror of
https://github.com/containers/gvisor-tap-vsock.git
synced 2025-10-05 16:56:50 +08:00
c56ed7ab4a
fsnotify/fsnotify can't watch a folder that contains a symlink into a socket or named pipe. Use poll-based mechanism to watch the file for the time being until we find a better way or fix the issue in the upstream. Signed-off-by: Fata Nugraha <fatanugraha@outlook.com>
102 lines
2.4 KiB
Go
102 lines
2.4 KiB
Go
package utils
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import (
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"os"
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"path/filepath"
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"sync/atomic"
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"testing"
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"time"
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"github.com/stretchr/testify/assert"
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)
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func TestFileWatcher(t *testing.T) {
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if testing.Short() {
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// we can't really speed up the test as we need to wait for the
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// inode cache to expire so that we can read the latest
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// file's modtime.
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t.Skip("skipping test in short mode.")
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}
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t.Parallel()
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assertSpec := func(t *testing.T, watchedPath, filePath string) {
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t.Helper()
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fw := NewFileWatcher(watchedPath)
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var numTriggered atomic.Int64
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assertNumTriggered := func(expected int) {
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time.Sleep(fw.pollInterval + 200*time.Millisecond)
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assert.Equal(t, int64(expected), numTriggered.Load())
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}
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fw.Start(func() {
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numTriggered.Add(1)
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})
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// important: adding a random sleep here so that the next fw's poll
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// results in inode cache miss, hence calling stat will return the latest
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// modtime.
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time.Sleep(1 * time.Second)
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// CASE: can detect changes to the file.
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if err := os.WriteFile(filePath, []byte("2"), 0o600); err != nil {
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panic(err)
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}
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assertNumTriggered(1)
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// CASE: can detect "swap"-based file modification.
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tmpFile := filepath.Join(filepath.Dir(filePath), "tmp.txt")
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if err := os.WriteFile(tmpFile, []byte("lol"), 0o600); err != nil {
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panic(err)
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}
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if err := os.Rename(tmpFile, filePath); err != nil {
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panic(err)
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}
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assertNumTriggered(2)
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// CASE: combine multiple partial writes into single event.
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fd, err := os.OpenFile(filePath, os.O_WRONLY|os.O_TRUNC, 0o600)
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if err != nil {
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panic(err)
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}
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// we assume these writes happens in less than 50ms.
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_, _ = fd.Write([]byte("a"))
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_ = fd.Sync()
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_, _ = fd.Write([]byte("b"))
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fd.Close()
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assertNumTriggered(3)
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// CASE: closed file watcher should not call the callback after Stop() is called.
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fw.Stop()
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if err := os.WriteFile(filePath, []byte("2"), 0o600); err != nil {
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panic(err)
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}
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assertNumTriggered(3) // does not change.
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}
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t.Run("normal file", func(t *testing.T) {
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t.Parallel()
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dir := t.TempDir()
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path := filepath.Join(dir, "file.txt")
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_ = os.WriteFile(path, []byte("1"), 0o600)
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assertSpec(t, path, path)
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})
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t.Run("symlink", func(t *testing.T) {
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t.Parallel()
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dir := t.TempDir()
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path := filepath.Join(dir, "file.txt")
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_ = os.WriteFile(path, []byte("1"), 0o600)
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symlinkPath := filepath.Join(dir, "symlink.txt")
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_ = os.Symlink(path, symlinkPath)
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assertSpec(t, symlinkPath, path)
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})
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}
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