add hot reloading for fs config #2179
+296
−40
There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,152 @@ | ||
| /* | ||
| Copyright The containerd Authors. | ||
|
|
||
| Licensed under the Apache License, Version 2.0 (the "License"); | ||
| you may not use this file except in compliance with the License. | ||
| You may obtain a copy of the License at | ||
|
|
||
| http://www.apache.org/licenses/LICENSE-2.0 | ||
|
|
||
| Unless required by applicable law or agreed to in writing, software | ||
| distributed under the License is distributed on an "AS IS" BASIS, | ||
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| See the License for the specific language governing permissions and | ||
| limitations under the License. | ||
| */ | ||
|
|
||
| package main | ||
|
|
||
| import ( | ||
| "context" | ||
| "path/filepath" | ||
| "reflect" | ||
| "sync" | ||
| "time" | ||
|
|
||
| "github.com/containerd/containerd/v2/core/snapshots" | ||
| "github.com/containerd/log" | ||
| fsconfig "github.com/containerd/stargz-snapshotter/fs/config" | ||
| "github.com/fsnotify/fsnotify" | ||
| "github.com/pelletier/go-toml" | ||
| ) | ||
|
|
||
| // WatchConfig monitors the specified configuration file for changes. | ||
| // It triggers the config reload when a change is detected. | ||
| func WatchConfig( | ||
| ctx context.Context, | ||
| filePath string, | ||
| rs snapshots.Snapshotter, | ||
| initialConfig *fsconfig.Config, | ||
| ) error { | ||
| absFilePath, err := filepath.Abs(filePath) | ||
| if err != nil { | ||
| return err | ||
| } | ||
|
|
||
| watchDir := filepath.Dir(absFilePath) | ||
|
|
||
| watcher, err := fsnotify.NewWatcher() | ||
|
|
||
| if err != nil { | ||
| return err | ||
| } | ||
|
|
||
| if err := watcher.Add(watchDir); err != nil { | ||
| watcher.Close() | ||
| return err | ||
| } | ||
|
|
||
| log.G(ctx).Infof("started monitoring config file: %s", absFilePath) | ||
|
|
||
| cw := &configWatcher{ | ||
| lastConfig: initialConfig, | ||
| } | ||
|
|
||
| go func() { | ||
| defer watcher.Close() | ||
|
|
||
| var ( | ||
| debounceTimer *time.Timer | ||
| mu sync.Mutex | ||
|
Comment on lines
+67
to
+69
Member
There was a problem hiding this comment. Why is |
||
| ) | ||
|
|
||
| for { | ||
| select { | ||
| case event, ok := <-watcher.Events: | ||
| if !ok { | ||
| return | ||
| } | ||
|
|
||
| if event.Name == absFilePath { | ||
| // Trigger on Write, Create, Rename, or Chmod events | ||
| // such as vim, nano, etc. | ||
| if event.Has(fsnotify.Write) || event.Has(fsnotify.Create) || | ||
| event.Has(fsnotify.Rename) || event.Has(fsnotify.Chmod) { | ||
|
Comment on lines
+79
to
+83
Member
There was a problem hiding this comment.
If the file is renamed, the next change won't be detected, will it? Is this an expected behaviour? |
||
|
|
||
| mu.Lock() | ||
| if debounceTimer != nil { | ||
| debounceTimer.Stop() | ||
| } | ||
| // Debounce changes with a 50ms delay | ||
| debounceTimer = time.AfterFunc(50*time.Millisecond, func() { | ||
| log.G(ctx).Infof("config file modification detected: %s", absFilePath) | ||
| cw.reload(ctx, absFilePath, rs) | ||
| }) | ||
| mu.Unlock() | ||
| } | ||
| } | ||
|
|
||
| case err, ok := <-watcher.Errors: | ||
| if !ok { | ||
| return | ||
| } | ||
| log.G(ctx).WithError(err).Error("config watcher encountered an error") | ||
| } | ||
| } | ||
| }() | ||
|
|
||
| return nil | ||
| } | ||
|
|
||
| type configWatcher struct { | ||
| lastConfig *fsconfig.Config | ||
| mu sync.Mutex | ||
| } | ||
|
|
||
| func (w *configWatcher) reload(ctx context.Context, configPath string, rs snapshots.Snapshotter) { | ||
| log.G(ctx).Infof("Config file %s changed, reloading...", configPath) | ||
| var newConfig snapshotterConfig | ||
| tree, err := toml.LoadFile(configPath) | ||
| if err != nil { | ||
| log.G(ctx).WithError(err).Error("failed to reload config file") | ||
| return | ||
| } | ||
| if err := tree.Unmarshal(&newConfig); err != nil { | ||
| log.G(ctx).WithError(err).Error("failed to unmarshal config") | ||
| return | ||
| } | ||
|
|
||
| newFsConfig := newConfig.Config.Config | ||
|
|
||
| w.mu.Lock() | ||
| defer w.mu.Unlock() | ||
|
|
||
| if w.lastConfig != nil && reflect.DeepEqual(*w.lastConfig, newFsConfig) { | ||
| log.G(ctx).Info("Config content unchanged, skipping update") | ||
| return | ||
| } | ||
|
|
||
| if updater, ok := rs.(interface { | ||
| UpdateConfig(context.Context, fsconfig.Config) error | ||
| }); ok { | ||
| log.G(ctx).Debugf("applying new config: %+v", newFsConfig) | ||
| if err := updater.UpdateConfig(ctx, newFsConfig); err != nil { | ||
| log.G(ctx).WithError(err).Error("failed to update config") | ||
| } else { | ||
| log.G(ctx).Info("Config updated successfully") | ||
| cfgCopy := newFsConfig | ||
| w.lastConfig = &cfgCopy | ||
| } | ||
| } else { | ||
| log.G(ctx).Warn("snapshotter does not support config update") | ||
| } | ||
| } | ||
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
You don't need to export this symbol.