Merge pull request #1546 from jedevc/v0.10-inspect-lazy-attestations

[v0.10] Lazily load attestation data in imagetools inspect

util/imagetools/loader.go

@@ -49,6 +49,9 @@ type asset struct {
 	config     *ocispec.Image
 	sbom       *sbomStub
 	provenance *provenanceStub
+
+	deferredSbom       func() (*sbomStub, error)
+	deferredProvenance func() (*provenanceStub, error)
 }
 
 type result struct {
@@ -261,37 +264,41 @@ type sbomStub struct {
 
 func (l *loader) scanSBOM(ctx context.Context, fetcher remotes.Fetcher, r *result, refs []digest.Digest, as *asset) error {
 	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.in-toto+json", "intoto")
+	as.deferredSbom = func() (*sbomStub, error) {
+		var sbom *sbomStub
 		for _, dgst := range refs {
 			mfst, ok := r.manifests[dgst]
 			if !ok {
-			return errors.Errorf("referenced image %s not found", dgst)
+				return nil, errors.Errorf("referenced image %s not found", dgst)
 			}
 			for _, layer := range mfst.manifest.Layers {
 				if layer.MediaType == "application/vnd.in-toto+json" && layer.Annotations["in-toto.io/predicate-type"] == "https://spdx.dev/Document" {
 					_, err := remotes.FetchHandler(l.cache, fetcher)(ctx, layer)
 					if err != nil {
-					return err
+						return nil, err
 					}
 					dt, err := content.ReadBlob(ctx, l.cache, layer)
 					if err != nil {
-					return err
+						return nil, err
 					}
 					var spdx struct {
 						Predicate interface{} `json:"predicate"`
 					}
 					if err := json.Unmarshal(dt, &spdx); err != nil {
-					return err
+						return nil, err
 					}
 
-				if as.sbom == nil {
-					as.sbom = &sbomStub{}
-					as.sbom.SPDX = spdx.Predicate
+					if sbom == nil {
+						sbom = &sbomStub{}
+						sbom.SPDX = spdx.Predicate
 					} else {
-					as.sbom.AdditionalSPDXs = append(as.sbom.AdditionalSPDXs, spdx.Predicate)
+						sbom.AdditionalSPDXs = append(sbom.AdditionalSPDXs, spdx.Predicate)
 					}
 				}
 			}
 		}
+		return sbom, nil
+	}
 	return nil
 }
 
@@ -301,34 +308,38 @@ type provenanceStub struct {
 
 func (l *loader) scanProvenance(ctx context.Context, fetcher remotes.Fetcher, r *result, refs []digest.Digest, as *asset) error {
 	ctx = remotes.WithMediaTypeKeyPrefix(ctx, "application/vnd.in-toto+json", "intoto")
+	as.deferredProvenance = func() (*provenanceStub, error) {
+		var provenance *provenanceStub
 		for _, dgst := range refs {
 			mfst, ok := r.manifests[dgst]
 			if !ok {
-			return errors.Errorf("referenced image %s not found", dgst)
+				return nil, errors.Errorf("referenced image %s not found", dgst)
 			}
 			for _, layer := range mfst.manifest.Layers {
 				if layer.MediaType == "application/vnd.in-toto+json" && strings.HasPrefix(layer.Annotations["in-toto.io/predicate-type"], "https://slsa.dev/provenance/") {
 					_, err := remotes.FetchHandler(l.cache, fetcher)(ctx, layer)
 					if err != nil {
-					return err
+						return nil, err
 					}
 					dt, err := content.ReadBlob(ctx, l.cache, layer)
 					if err != nil {
-					return err
+						return nil, err
 					}
 					var slsa struct {
 						Predicate interface{} `json:"predicate"`
 					}
 					if err := json.Unmarshal(dt, &slsa); err != nil {
-					return err
+						return nil, err
 					}
-				as.provenance = &provenanceStub{
+					provenance = &provenanceStub{
 						SLSA: slsa.Predicate,
 					}
 					break
 				}
 			}
 		}
+		return provenance, nil
+	}
 	return nil
 }
 
@@ -346,30 +357,50 @@ func (r *result) Configs() map[string]*ocispec.Image {
 	return res
 }
 
-func (r *result) Provenance() map[string]provenanceStub {
+func (r *result) Provenance() (map[string]provenanceStub, error) {
 	if len(r.assets) == 0 {
-		return nil
+		return nil, nil
 	}
 	res := make(map[string]provenanceStub)
 	for p, a := range r.assets {
-		if a.provenance == nil {
+		if a.deferredProvenance == nil {
 			continue
 		}
+		if a.provenance == nil {
+			provenance, err := a.deferredProvenance()
+			if err != nil {
+				return nil, err
+			}
+			if provenance == nil {
+				continue
+			}
+			a.provenance = provenance
+		}
 		res[p] = *a.provenance
 	}
-	return res
+	return res, nil
 }
 
-func (r *result) SBOM() map[string]sbomStub {
+func (r *result) SBOM() (map[string]sbomStub, error) {
 	if len(r.assets) == 0 {
-		return nil
+		return nil, nil
 	}
 	res := make(map[string]sbomStub)
 	for p, a := range r.assets {
-		if a.sbom == nil {
+		if a.deferredSbom == nil {
 			continue
 		}
+		if a.sbom == nil {
+			sbom, err := a.deferredSbom()
+			if err != nil {
+				return nil, err
+			}
+			if sbom == nil {
+				continue
+			}
+			a.sbom = sbom
+		}
 		res[p] = *a.sbom
 	}
-	return res
+	return res, nil
 }

util/imagetools/printers.go

@@ -99,8 +99,6 @@ func (p *Printer) Print(raw bool, out io.Writer) error {
 	}
 
 	imageconfigs := res.Configs()
-	provenances := res.Provenance()
-	sboms := res.SBOM()
 	format := tpl.Root.String()
 
 	var mfst interface{}
@@ -142,44 +140,22 @@ func (p *Printer) Print(raw bool, out io.Writer) error {
 		}
 	default:
 		if len(res.platforms) > 1 {
-			return tpl.Execute(out, struct {
-				Name       string                     `json:"name,omitempty"`
-				Manifest   interface{}                `json:"manifest,omitempty"`
-				Image      map[string]*ocispecs.Image `json:"image,omitempty"`
-				Provenance map[string]provenanceStub  `json:"Provenance,omitempty"`
-				SBOM       map[string]sbomStub        `json:"SBOM,omitempty"`
-			}{
+			return tpl.Execute(out, tplInputs{
 				Name:     p.name,
 				Manifest: mfst,
 				Image:    imageconfigs,
-				Provenance: provenances,
-				SBOM:       sboms,
+				result:   res,
 			})
 		}
 		var ic *ocispecs.Image
 		for _, v := range imageconfigs {
 			ic = v
 		}
-		var provenance provenanceStub
-		for _, v := range provenances {
-			provenance = v
-		}
-		var sbom sbomStub
-		for _, v := range sboms {
-			sbom = v
-		}
-		return tpl.Execute(out, struct {
-			Name       string          `json:"name,omitempty"`
-			Manifest   interface{}     `json:"manifest,omitempty"`
-			Image      *ocispecs.Image `json:"image,omitempty"`
-			Provenance provenanceStub  `json:"Provenance,omitempty"`
-			SBOM       sbomStub        `json:"SBOM,omitempty"`
-		}{
+		return tpl.Execute(out, tplInput{
 			Name:     p.name,
 			Manifest: mfst,
 			Image:    ic,
-			Provenance: provenance,
-			SBOM:       sbom,
+			result:   res,
 		})
 	}
 
@@ -227,3 +203,49 @@ func (p *Printer) printManifestList(out io.Writer) error {
 	}
 	return w.Flush()
 }
+
+type tplInput struct {
+	Name     string          `json:"name,omitempty"`
+	Manifest interface{}     `json:"manifest,omitempty"`
+	Image    *ocispecs.Image `json:"image,omitempty"`
+
+	result *result
+}
+
+func (inp tplInput) SBOM() (sbomStub, error) {
+	sbom, err := inp.result.SBOM()
+	if err != nil {
+		return sbomStub{}, nil
+	}
+	for _, v := range sbom {
+		return v, nil
+	}
+	return sbomStub{}, nil
+}
+
+func (inp tplInput) Provenance() (provenanceStub, error) {
+	provenance, err := inp.result.Provenance()
+	if err != nil {
+		return provenanceStub{}, nil
+	}
+	for _, v := range provenance {
+		return v, nil
+	}
+	return provenanceStub{}, nil
+}
+
+type tplInputs struct {
+	Name     string                     `json:"name,omitempty"`
+	Manifest interface{}                `json:"manifest,omitempty"`
+	Image    map[string]*ocispecs.Image `json:"image,omitempty"`
+
+	result *result
+}
+
+func (inp tplInputs) SBOM() (map[string]sbomStub, error) {
+	return inp.result.SBOM()
+}
+
+func (inp tplInputs) Provenance() (map[string]provenanceStub, error) {
+	return inp.result.Provenance()
+}