MAISTRA-1862 Fix NilPointerException when images can't be pulled (#183)

This also improves logging by dropping some loglevels and always
logging errors when calling pullStrategy.GetImage()

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

mec/pkg/model/types.go

@@ -45,11 +45,10 @@ const (
 )
 
 func (i *ImageRef) String() string {
-	tag := i.Tag
 	if i.SHA256 != "" {
-		tag = fmt.Sprintf("sha256:%s", i.SHA256)
+		return fmt.Sprintf("%s/%s@sha256:%s", i.Hub, i.Repository, i.SHA256)
 	}
-	return fmt.Sprintf("%s/%s:%s", i.Hub, i.Repository, tag)
+	return fmt.Sprintf("%s/%s:%s", i.Hub, i.Repository, i.Tag)
 }
 
 func StringToImageRef(ref string) *ImageRef {

mec/pkg/pullstrategy/ossm/strategy.go

@@ -102,11 +102,11 @@ func (p *ossmPullStrategy) GetImage(image *model.ImageRef) (model.Image, error)
 	if image.SHA256 == "" {
 		return nil, fmt.Errorf("getImage() only works for pinned images")
 	}
-	imageID, err := podman.GetImageID(image.String())
+	imageID, err := podman.GetImageID(image.SHA256)
 	if err != nil {
 		return nil, err
 	} else if imageID == "" {
-		return nil, fmt.Errorf("failed to read imageID from podman CLI")
+		return nil, nil
 	}
 	manifest, err := extractManifest(imageID)
 	if err != nil {
@@ -130,19 +130,39 @@ func (p *ossmPullStrategy) PullImage(image *model.ImageRef) (model.Image, error)
 		if errors.IsNotFound(err) {
 			createdIsi, err := p.createImageStreamImport(image)
 			if err != nil {
-				log.Errorf("failed to create ImageStreamImport: %s, attempt %d", err, attempt)
+				log.Warnf("failed to create ImageStreamImport: %s, attempt %d", err, attempt)
 				continue
 			}
 			log.Infof("Created ImageStreamImport %s", createdIsi.Name)
 		}
 		if err != nil {
-			log.Errorf("failed to Get() ImageStream: %s, attempt %d", err, attempt)
+			log.Warnf("failed to Get() ImageStream: %s, attempt %d", err, attempt)
+			continue
+		}
+		if imageStream != nil {
+			for _, tag := range imageStream.Spec.Tags {
+				if tag.From.Name == image.String() {
+					break
+				}
+			}
+			createdIsi, err := p.createImageStreamImport(image)
+			if err != nil {
+				log.Warnf("failed to create ImageStreamImport: %s, attempt %d", err, attempt)
+				continue
+			}
+			log.Infof("Created ImageStreamImport %s", createdIsi.Name)
 		}
 	}
 	if err != nil {
 		return nil, err
 	}
 
+	for _, condition := range imageStream.Status.Tags[0].Conditions {
+		if condition.Status == corev1.ConditionFalse {
+			return nil, fmt.Errorf("failed to pull image: %s", condition.Message)
+		}
+	}
+
 	// TODO implement importing always when ImagePullPolicy == Always
 	repo := imageStream.Status.DockerImageRepository
 	sha := imageStream.Status.Tags[0].Items[0].Image

mec/pkg/server/worker.go

@@ -88,8 +88,15 @@ func (w *Worker) processEvent(event ExtensionEvent) {
 		imageRef.SHA256 = extension.Status.Deployment.ContainerSHA256
 	}
 
-	img, err := w.pullStrategy.GetImage(imageRef)
-	if err != nil {
+	var img model.Image
+	var err error
+	if imageRef.SHA256 != "" {
+		img, err = w.pullStrategy.GetImage(imageRef)
+		if err != nil {
+			log.Errorf("Failed to check whether image is already present: %s", err)
+		}
+	}
+	if img == nil {
 		log.Infof("Image %s not present. Pulling", imageRef.String())
 		img, err = w.pullStrategy.PullImage(imageRef)
 		if err != nil {