cloudfoundry/cf-k8s-controllers

package tools

import (
    "context"

    "github.com/fsnotify/fsnotify"
    "github.com/go-logr/logr"
)

func WatchForConfigChangeEvents(ctx context.Context, configFilePath string, logger logr.Logger, eventChan chan string) error {
    logger.V(1).Info("starting config watcher")

    watcher, err := fsnotify.NewWatcher()
    if err != nil {
        return err
    }

    defer watcher.Close()

    err = watcher.Add(configFilePath)
    if err != nil {
        return err
    }

    eventChan <- configFilePath

    for {
        select {
        case event, ok := <-watcher.Events:
            if !ok {
                return nil
            }

            logger.V(1).Info("config change event", "event", event)

            if isWrite(event) || isCreate(event) {
                eventChan <- configFilePath
            }

        case err, ok := <-watcher.Errors:
            if !ok {
                return nil
            }

            logger.Error(err, "config watcher error")

        case <-ctx.Done():
            logger.V(1).Info("stopping config watcher")
            return nil
        }
    }
}

func isWrite(event fsnotify.Event) bool {
    return event.Op&fsnotify.Write == fsnotify.Write
}

func isCreate(event fsnotify.Event) bool {
    return event.Op&fsnotify.Create == fsnotify.Create
}