X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/7e85063ebffe3a6d990fb0b2eac62b1906660a21..bc3637c90f8e4e3d1bdc61546c3d7fc53da135f6:/lib/controller/localdb/conn.go

diff --git a/lib/controller/localdb/conn.go b/lib/controller/localdb/conn.go
index edbbcb09cd..323e660c6f 100644
--- a/lib/controller/localdb/conn.go
+++ b/lib/controller/localdb/conn.go
@@ -11,23 +11,25 @@ import (
 	"net/http"
 	"os"
 	"strings"
+	"time"
 
 	"git.arvados.org/arvados.git/lib/controller/railsproxy"
 	"git.arvados.org/arvados.git/lib/controller/rpc"
 	"git.arvados.org/arvados.git/sdk/go/arvados"
 	"git.arvados.org/arvados.git/sdk/go/ctxlog"
 	"git.arvados.org/arvados.git/sdk/go/httpserver"
-	"github.com/fsnotify/fsnotify"
 	"github.com/sirupsen/logrus"
 )
 
 type railsProxy = rpc.Conn
 
 type Conn struct {
-	cluster          *arvados.Cluster
-	*railsProxy      // handles API methods that aren't defined on Conn itself
-	vocabularyCache  *arvados.Vocabulary
-	reloadVocabulary bool
+	cluster                    *arvados.Cluster
+	*railsProxy                // handles API methods that aren't defined on Conn itself
+	vocabularyCache            *arvados.Vocabulary
+	vocabularyFileModTime      time.Time
+	lastVocabularyRefreshCheck time.Time
+	lastVocabularyError        error
 	loginController
 }
 
@@ -69,43 +71,35 @@ func (conn *Conn) checkProperties(ctx context.Context, properties interface{}) e
 	return nil
 }
 
-func watchVocabulary(logger logrus.FieldLogger, vocPath string, fn func()) {
-	watcher, err := fsnotify.NewWatcher()
-	if err != nil {
-		logger.WithError(err).Error("vocabulary fsnotify setup failed")
-		return
+func (conn *Conn) maybeRefreshVocabularyCache(logger logrus.FieldLogger) error {
+	if conn.lastVocabularyRefreshCheck.Add(time.Second).After(time.Now()) {
+		// Throttle the access to disk to at most once per second.
+		return nil
 	}
-	defer watcher.Close()
-
-	err = watcher.Add(vocPath)
+	conn.lastVocabularyRefreshCheck = time.Now()
+	fi, err := os.Stat(conn.cluster.API.VocabularyPath)
 	if err != nil {
-		logger.WithError(err).Error("vocabulary file watcher failed")
-		return
+		err = fmt.Errorf("couldn't stat vocabulary file %q: %v", conn.cluster.API.VocabularyPath, err)
+		conn.lastVocabularyError = err
+		return err
 	}
-
-	for {
-		select {
-		case err, ok := <-watcher.Errors:
-			if !ok {
-				return
-			}
-			logger.WithError(err).Warn("vocabulary file watcher error")
-		case _, ok := <-watcher.Events:
-			if !ok {
-				return
-			}
-			for len(watcher.Events) > 0 {
-				<-watcher.Events
-			}
-			fn()
+	if fi.ModTime().After(conn.vocabularyFileModTime) {
+		err = conn.loadVocabularyFile()
+		if err != nil {
+			conn.lastVocabularyError = err
+			return err
 		}
+		conn.vocabularyFileModTime = fi.ModTime()
+		conn.lastVocabularyError = nil
+		logger.Info("vocabulary file reloaded successfully")
 	}
+	return nil
 }
 
 func (conn *Conn) loadVocabularyFile() error {
 	vf, err := os.ReadFile(conn.cluster.API.VocabularyPath)
 	if err != nil {
-		return fmt.Errorf("couldn't read vocabulary file %q: %v", conn.cluster.API.VocabularyPath, err)
+		return fmt.Errorf("couldn't reading the vocabulary file: %v", err)
 	}
 	mk := make([]string, 0, len(conn.cluster.Collections.ManagedProperties))
 	for k := range conn.cluster.Collections.ManagedProperties {
@@ -115,18 +109,24 @@ func (conn *Conn) loadVocabularyFile() error {
 	if err != nil {
 		return fmt.Errorf("while loading vocabulary file %q: %s", conn.cluster.API.VocabularyPath, err)
 	}
-	err = voc.Validate()
-	if err != nil {
-		return fmt.Errorf("while validating vocabulary file %q: %s", conn.cluster.API.VocabularyPath, err)
-	}
 	conn.vocabularyCache = voc
 	return nil
 }
 
+// LastVocabularyError returns the last error encountered while loading the
+// vocabulary file.
+// Implements health.Func
+func (conn *Conn) LastVocabularyError() error {
+	conn.maybeRefreshVocabularyCache(ctxlog.FromContext(context.Background()))
+	return conn.lastVocabularyError
+}
+
 // VocabularyGet refreshes the vocabulary cache if necessary and returns it.
 func (conn *Conn) VocabularyGet(ctx context.Context) (arvados.Vocabulary, error) {
 	if conn.cluster.API.VocabularyPath == "" {
-		return arvados.Vocabulary{}, nil
+		return arvados.Vocabulary{
+			Tags: map[string]arvados.VocabularyTag{},
+		}, nil
 	}
 	logger := ctxlog.FromContext(ctx)
 	if conn.vocabularyCache == nil {
@@ -136,19 +136,10 @@ func (conn *Conn) VocabularyGet(ctx context.Context) (arvados.Vocabulary, error)
 			logger.WithError(err).Error("error loading vocabulary file")
 			return arvados.Vocabulary{}, err
 		}
-		go watchVocabulary(logger, conn.cluster.API.VocabularyPath, func() {
-			logger.Info("vocabulary file changed, it'll be reloaded next time it's needed")
-			conn.reloadVocabulary = true
-		})
-	} else if conn.reloadVocabulary {
-		// Requested reload of vocabulary file.
-		conn.reloadVocabulary = false
-		err := conn.loadVocabularyFile()
-		if err != nil {
-			logger.WithError(err).Error("error reloading vocabulary file - ignoring")
-		} else {
-			logger.Info("vocabulary file reloaded successfully")
-		}
+	}
+	err := conn.maybeRefreshVocabularyCache(logger)
+	if err != nil {
+		logger.WithError(err).Error("error reloading vocabulary file - ignoring")
 	}
 	return *conn.vocabularyCache, nil
 }