watcher.go

Documentation: github.com/redhat-developer/odo/pkg/apiserver-impl/sse

     1  package sse
     2  
     3  import (
     4  	"context"
     5  
     6  	"github.com/fsnotify/fsnotify"
     7  	"k8s.io/klog"
     8  )
     9  
    10  func (n *Notifier) watchDevfileChanges(ctx context.Context, devfileFiles []string) error {
    11  	devfileWatcher, err := fsnotify.NewWatcher()
    12  	if err != nil {
    13  		return err
    14  	}
    15  
    16  	go func() {
    17  		for {
    18  			select {
    19  			case <-ctx.Done():
    20  				klog.V(2).Infof("context done, reason: %v", ctx.Err())
    21  				cErr := devfileWatcher.Close()
    22  				if cErr != nil {
    23  					klog.V(2).Infof("error closing devfileWater: %v", cErr)
    24  				}
    25  				return
    26  			case ev, ok := <-devfileWatcher.Events:
    27  				if !ok {
    28  					return
    29  				}
    30  				klog.V(7).Infof("event: %v", ev)
    31  				devfileContent, rErr := n.fsys.ReadFile(n.devfilePath)
    32  				if rErr != nil {
    33  					klog.V(1).Infof("unable to read Devfile at path %q: %v", n.devfilePath, rErr)
    34  					continue
    35  				}
    36  				n.eventsChan <- Event{
    37  					eventType: DevfileUpdated,
    38  					data: map[string]string{
    39  						"path":      ev.Name,
    40  						"operation": ev.Op.String(),
    41  						"content":   string(devfileContent),
    42  					},
    43  				}
    44  				if ev.Has(fsnotify.Remove) {
    45  					// For some reason, depending on the editor used to edit the file, changes would be detected only once.
    46  					// Workaround recommended is to re-add the path to the watcher.
    47  					// See https://github.com/fsnotify/fsnotify/issues/363
    48  					wErr := devfileWatcher.Remove(ev.Name)
    49  					if wErr != nil {
    50  						klog.V(7).Infof("error removing file watch: %v", wErr)
    51  					}
    52  					wErr = devfileWatcher.Add(ev.Name)
    53  					if wErr != nil {
    54  						klog.V(0).Infof("error re-adding file watch: %v", wErr)
    55  					}
    56  				}
    57  			case wErr, ok := <-devfileWatcher.Errors:
    58  				if !ok {
    59  					return
    60  				}
    61  				klog.V(0).Infof("error on file watch: %v", wErr)
    62  			}
    63  		}
    64  	}()
    65  
    66  	for _, f := range devfileFiles {
    67  		err = devfileWatcher.Add(f)
    68  		if err != nil {
    69  			klog.V(0).Infof("error adding watcher for path %q: %v", f, err)
    70  		} else {
    71  			klog.V(7).Infof("added watcher for path %q", f)
    72  		}
    73  	}
    74  
    75  	return nil
    76  }
    77
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