Renamed to --oci-layout-path and added a unit test.

2026-10-18 17:42:49 +02:00 · 2019-08-24 01:28:58 -07:00
parent 7949d0de1d
commit 11f3b791cd
8 changed files with 485 additions and 6 deletions
@@ -0,0 +1,16 @@
+// Copyright 2018 Google LLC All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package validate provides methods for validating image correctness.
+package validate
@@ -0,0 +1,297 @@
+// Copyright 2018 Google LLC All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"strings"
+
+	"github.com/google/go-cmp/cmp"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+)
+
+// Image validates that img does not violate any invariants of the image format.
+func Image(img v1.Image) error {
+	errs := []string{}
+	if err := validateLayers(img); err != nil {
+		errs = append(errs, fmt.Sprintf("validating layers: %v", err))
+	}
+
+	if err := validateConfig(img); err != nil {
+		errs = append(errs, fmt.Sprintf("validating config: %v", err))
+	}
+
+	if err := validateManifest(img); err != nil {
+		errs = append(errs, fmt.Sprintf("validating manifest: %v", err))
+	}
+
+	if len(errs) != 0 {
+		return errors.New(strings.Join(errs, "\n\n"))
+	}
+	return nil
+}
+
+func validateConfig(img v1.Image) error {
+	cn, err := img.ConfigName()
+	if err != nil {
+		return err
+	}
+
+	rc, err := img.RawConfigFile()
+	if err != nil {
+		return err
+	}
+
+	hash, size, err := v1.SHA256(bytes.NewReader(rc))
+	if err != nil {
+		return err
+	}
+
+	m, err := img.Manifest()
+	if err != nil {
+		return err
+	}
+
+	cf, err := img.ConfigFile()
+	if err != nil {
+		return err
+	}
+
+	pcf, err := v1.ParseConfigFile(bytes.NewReader(rc))
+	if err != nil {
+		return err
+	}
+
+	errs := []string{}
+	if cn != hash {
+		errs = append(errs, fmt.Sprintf("mismatched config digest: ConfigName()=%s, SHA256(RawConfigFile())=%s", cn, hash))
+	}
+
+	if want, got := m.Config.Size, size; want != got {
+		errs = append(errs, fmt.Sprintf("mismatched config size: Manifest.Config.Size()=%d, len(RawConfigFile())=%d", want, got))
+	}
+
+	if diff := cmp.Diff(pcf, cf); diff != "" {
+		errs = append(errs, fmt.Sprintf("mismatched config content: (-ParseConfigFile(RawConfigFile()) +ConfigFile()) %s", diff))
+	}
+
+	if cf.RootFS.Type != "layers" {
+		errs = append(errs, fmt.Sprintf("invalid ConfigFile.RootFS.Type: %q != %q", cf.RootFS.Type, "layers"))
+	}
+
+	if len(errs) != 0 {
+		return errors.New(strings.Join(errs, "\n"))
+	}
+
+	return nil
+}
+
+func validateLayers(img v1.Image) error {
+	layers, err := img.Layers()
+	if err != nil {
+		return err
+	}
+
+	digests := []v1.Hash{}
+	diffids := []v1.Hash{}
+	sizes := []int64{}
+	for _, layer := range layers {
+		// TODO: Test layer.Uncompressed.
+		compressed, err := layer.Compressed()
+		if err != nil {
+			return err
+		}
+
+		// Keep track of compressed digest.
+		digester := sha256.New()
+		// Everything read from compressed is written to digester to compute digest.
+		hashCompressed := io.TeeReader(compressed, digester)
+
+		// Call io.Copy to write from the layer Reader through to the tarReader on
+		// the other side of the pipe.
+		pr, pw := io.Pipe()
+		var size int64
+		go func() {
+			n, err := io.Copy(pw, hashCompressed)
+			if err != nil {
+				pw.CloseWithError(err)
+				return
+			}
+			size = n
+
+			// Now close the compressed reader, to flush the gzip stream
+			// and calculate digest/diffID/size. This will cause pr to
+			// return EOF which will cause readers of the Compressed stream
+			// to finish reading.
+			pw.CloseWithError(compressed.Close())
+		}()
+
+		// Read the bytes through gzip.Reader to compute the DiffID.
+		uncompressed, err := gzip.NewReader(pr)
+		if err != nil {
+			return err
+		}
+		diffider := sha256.New()
+		hashUncompressed := io.TeeReader(uncompressed, diffider)
+
+		// Ensure there aren't duplicate file paths.
+		tarReader := tar.NewReader(hashUncompressed)
+		files := make(map[string]struct{})
+		for {
+			hdr, err := tarReader.Next()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				return err
+			}
+			if _, ok := files[hdr.Name]; ok {
+				return fmt.Errorf("duplicate file path: %s", hdr.Name)
+			}
+			files[hdr.Name] = struct{}{}
+		}
+
+		// Discard any trailing padding that the tar.Reader doesn't consume.
+		if _, err := io.Copy(ioutil.Discard, hashUncompressed); err != nil {
+			return err
+		}
+
+		if err := uncompressed.Close(); err != nil {
+			return err
+		}
+
+		digest := v1.Hash{
+			Algorithm: "sha256",
+			Hex:       hex.EncodeToString(digester.Sum(make([]byte, 0, digester.Size()))),
+		}
+
+		diffid := v1.Hash{
+			Algorithm: "sha256",
+			Hex:       hex.EncodeToString(diffider.Sum(make([]byte, 0, diffider.Size()))),
+		}
+
+		// Compute all of these first before we call Config() and Manifest() to allow
+		// for lazy access e.g. for stream.Layer.
+		digests = append(digests, digest)
+		diffids = append(diffids, diffid)
+		sizes = append(sizes, size)
+	}
+
+	cf, err := img.ConfigFile()
+	if err != nil {
+		return err
+	}
+
+	m, err := img.Manifest()
+	if err != nil {
+		return err
+	}
+
+	errs := []string{}
+	for i, layer := range layers {
+		digest, err := layer.Digest()
+		if err != nil {
+			return err
+		}
+		diffid, err := layer.DiffID()
+		if err != nil {
+			return err
+		}
+		size, err := layer.Size()
+		if err != nil {
+			return err
+		}
+
+		if digest != digests[i] {
+			errs = append(errs, fmt.Sprintf("mismatched layer[%d] digest: Digest()=%s, SHA256(Compressed())=%s", i, digest, digests[i]))
+		}
+
+		if m.Layers[i].Digest != digests[i] {
+			errs = append(errs, fmt.Sprintf("mismatched layer[%d] digest: Manifest.Layers[%d].Digest=%s, SHA256(Compressed())=%s", i, i, m.Layers[i].Digest, digests[i]))
+		}
+
+		if diffid != diffids[i] {
+			errs = append(errs, fmt.Sprintf("mismatched layer[%d] diffid: DiffID()=%s, SHA256(Gunzip(Compressed()))=%s", i, diffid, diffids[i]))
+		}
+
+		if cf.RootFS.DiffIDs[i] != diffids[i] {
+			errs = append(errs, fmt.Sprintf("mismatched layer[%d] diffid: ConfigFile.RootFS.DiffIDs[%d]=%s, SHA256(Gunzip(Compressed()))=%s", i, i, cf.RootFS.DiffIDs[i], diffids[i]))
+		}
+
+		if size != sizes[i] {
+			errs = append(errs, fmt.Sprintf("mismatched layer[%d] size: Size()=%d, len(Compressed())=%d", i, size, sizes[i]))
+		}
+
+		if m.Layers[i].Size != sizes[i] {
+			errs = append(errs, fmt.Sprintf("mismatched layer[%d] size: Manifest.Layers[%d].Size=%d, len(Compressed())=%d", i, i, m.Layers[i].Size, sizes[i]))
+		}
+
+	}
+	if len(errs) != 0 {
+		return errors.New(strings.Join(errs, "\n"))
+	}
+
+	return nil
+}
+
+func validateManifest(img v1.Image) error {
+	digest, err := img.Digest()
+	if err != nil {
+		return err
+	}
+
+	rm, err := img.RawManifest()
+	if err != nil {
+		return err
+	}
+
+	hash, _, err := v1.SHA256(bytes.NewReader(rm))
+	if err != nil {
+		return err
+	}
+
+	m, err := img.Manifest()
+	if err != nil {
+		return err
+	}
+
+	pm, err := v1.ParseManifest(bytes.NewReader(rm))
+	if err != nil {
+		return err
+	}
+
+	errs := []string{}
+	if digest != hash {
+		errs = append(errs, fmt.Sprintf("mismatched manifest digest: Digest()=%s, SHA256(RawManifest())=%s", digest, hash))
+	}
+
+	if diff := cmp.Diff(pm, m); diff != "" {
+		errs = append(errs, fmt.Sprintf("mismatched manifest content: (-ParseManifest(RawManifest()) +Manifest()) %s", diff))
+	}
+
+	if len(errs) != 0 {
+		return errors.New(strings.Join(errs, "\n"))
+	}
+
+	return nil
+}
@@ -0,0 +1,123 @@
+// Copyright 2018 Google LLC All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package validate
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/google/go-cmp/cmp"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/types"
+)
+
+// Index validates that idx does not violate any invariants of the index format.
+func Index(idx v1.ImageIndex) error {
+	errs := []string{}
+
+	if err := validateChildren(idx); err != nil {
+		errs = append(errs, fmt.Sprintf("validating children: %v", err))
+	}
+
+	if err := validateIndexManifest(idx); err != nil {
+		errs = append(errs, fmt.Sprintf("validating index manifest: %v", err))
+	}
+
+	if len(errs) != 0 {
+		return errors.New(strings.Join(errs, "\n\n"))
+	}
+	return nil
+}
+
+func validateChildren(idx v1.ImageIndex) error {
+	manifest, err := idx.IndexManifest()
+	if err != nil {
+		return err
+	}
+
+	errs := []string{}
+	for i, desc := range manifest.Manifests {
+		switch desc.MediaType {
+		case types.OCIImageIndex, types.DockerManifestList:
+			idx, err := idx.ImageIndex(desc.Digest)
+			if err != nil {
+				return err
+			}
+			if err := Index(idx); err != nil {
+				errs = append(errs, fmt.Sprintf("failed to validate index Manifests[%d](%s): %v", i, desc.Digest, err))
+			}
+		case types.OCIManifestSchema1, types.DockerManifestSchema2:
+			img, err := idx.Image(desc.Digest)
+			if err != nil {
+				return err
+			}
+			if err := Image(img); err != nil {
+				errs = append(errs, fmt.Sprintf("failed to validate image Manifests[%d](%s): %v", i, desc.Digest, err))
+			}
+		default:
+			return fmt.Errorf("todo: validate index Blob()")
+		}
+	}
+
+	if len(errs) != 0 {
+		return errors.New(strings.Join(errs, "\n"))
+	}
+
+	return nil
+}
+
+func validateIndexManifest(idx v1.ImageIndex) error {
+	digest, err := idx.Digest()
+	if err != nil {
+		return err
+	}
+
+	rm, err := idx.RawManifest()
+	if err != nil {
+		return err
+	}
+
+	hash, _, err := v1.SHA256(bytes.NewReader(rm))
+	if err != nil {
+		return err
+	}
+
+	m, err := idx.IndexManifest()
+	if err != nil {
+		return err
+	}
+
+	pm, err := v1.ParseIndexManifest(bytes.NewReader(rm))
+	if err != nil {
+		return err
+	}
+
+	errs := []string{}
+	if digest != hash {
+		errs = append(errs, fmt.Sprintf("mismatched manifest digest: Digest()=%s, SHA256(RawManifest())=%s", digest, hash))
+	}
+
+	if diff := cmp.Diff(pm, m); diff != "" {
+		errs = append(errs, fmt.Sprintf("mismatched manifest content: (-ParseIndexManifest(RawManifest()) +Manifest()) %s", diff))
+	}
+
+	if len(errs) != 0 {
+		return errors.New(strings.Join(errs, "\n"))
+	}
+
+	return nil
+}