add unit test for ValidateLayout function

image/image_test.go

@@ -0,0 +1,331 @@
+// Copyright 2016 The Linux Foundation
+//
+// 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 image
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+const (
+	refTag = "latest"
+
+	layoutStr = `{"imageLayoutVersion": "1.0.0"}`
+
+	configStr = `{
+    "created": "2015-10-31T22:22:56.015925234Z",
+    "author": "Alyssa P. Hacker <[email protected]>",
+    "architecture": "amd64",
+    "os": "linux",
+    "config": {
+        "User": "alice",
+        "Memory": 2048,
+        "MemorySwap": 4096,
+        "CpuShares": 8,
+        "ExposedPorts": {
+            "8080/tcp": {}
+        },
+        "Env": [
+            "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+            "FOO=oci_is_a",
+            "BAR=well_written_spec"
+        ],
+        "Entrypoint": [
+            "/bin/my-app-binary"
+        ],
+        "Cmd": [
+            "--foreground",
+            "--config",
+            "/etc/my-app.d/default.cfg"
+        ],
+        "Volumes": {
+            "/var/job-result-data": {},
+            "/var/log/my-app-logs": {}
+        },
+        "WorkingDir": "/home/alice"
+    },
+    "rootfs": {
+      "diff_ids": [
+        "sha256:c6f988f4874bb0add23a778f753c65efe992244e148a1d2ec2a8b664fb66bbd1",
+        "sha256:5f70bf18a086007016e948b04aed3b82103a36bea41755b6cddfaf10ace3c6ef"
+      ],
+      "type": "layers"
+    },
+    "history": [
+      {
+        "created": "2015-10-31T22:22:54.690851953Z",
+        "created_by": "/bin/sh -c #(nop) ADD file:a3bc1e842b69636f9df5256c49c5374fb4eef1e281fe3f282c65fb853ee171c5 in /"
+      },
+      {
+        "created": "2015-10-31T22:22:55.613815829Z",
+        "created_by": "/bin/sh -c #(nop) CMD [\"sh\"]",
+        "empty_layer": true
+      }
+    ]
+}
+`
+)
+
+var (
+	refStr = `{"digest":"<manifest_digest>","mediaType":"application/vnd.oci.image.manifest.v1+json","size":<manifest_size>}`
+
+	manifestStr = `{
+    "annotations": null,
+    "config": {
+        "digest": "<config_digest>",
+        "mediaType": "application/vnd.oci.image.config.v1+json",
+        "size": <config_size>
+    },
+    "layers": [
+        {
+            "digest": "<layer_digest>",
+            "mediaType": "application/vnd.oci.image.layer.tar+gzip",
+            "size": <layer_size>
+        }
+    ],
+    "mediaType": "application/vnd.oci.image.manifest.v1+json",
+    "schemaVersion": 2
+}
+ `
+)
+
+type tarContent struct {
+	header *tar.Header
+	b      []byte
+}
+
+type imageLayout struct {
+	rootDir  string
+	layout   string
+	ref      string
+	manifest string
+	config   string
+	tarList  []tarContent
+}
+
+func TestValidateLayout(t *testing.T) {
+	root, err := ioutil.TempDir("", "oci-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(root)
+
+	il := imageLayout{
+		rootDir:  root,
+		layout:   layoutStr,
+		ref:      refTag,
+		manifest: manifestStr,
+		config:   configStr,
+		tarList: []tarContent{
+			tarContent{&tar.Header{Name: "test", Size: 4, Mode: 0600}, []byte("test")},
+		},
+	}
+
+	// create image layout bundle
+	err = createImageLayoutBundle(il)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = ValidateLayout(root, []string{refTag}, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func createImageLayoutBundle(il imageLayout) error {
+	err := os.MkdirAll(filepath.Join(il.rootDir, "blobs", "sha256"), 0700)
+	if err != nil {
+		return err
+	}
+
+	err = os.MkdirAll(filepath.Join(il.rootDir, "refs"), 0700)
+	if err != nil {
+		return err
+	}
+
+	// create image layout file
+	err = createLayoutFile(il.rootDir)
+	if err != nil {
+		return err
+	}
+
+	// create image layer blob file.
+	desc, err := createImageLayerFile(il.rootDir, il.tarList)
+	if err != nil {
+		return err
+	}
+	il.manifest = strings.Replace(il.manifest, "<layer_digest>", desc.Digest, 1)
+	il.manifest = strings.Replace(il.manifest, "<layer_size>", strconv.FormatInt(desc.Size, 10), 1)
+
+	desc, err = createConfigFile(il.rootDir, il.config)
+	if err != nil {
+		return err
+	}
+	il.manifest = strings.Replace(il.manifest, "<config_digest>", desc.Digest, 1)
+	il.manifest = strings.Replace(il.manifest, "<config_size>", strconv.FormatInt(desc.Size, 10), 1)
+
+	// create manifest blob file
+	desc, err = createManifestFile(il.rootDir, il.manifest)
+	if err != nil {
+		return err
+	}
+
+	return createRefFile(il.rootDir, il.ref, desc)
+}
+
+func createLayoutFile(root string) error {
+	layoutPath := filepath.Join(root, "oci-layout")
+	f, err := os.Create(layoutPath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	_, err = io.Copy(f, bytes.NewBuffer([]byte(layoutStr)))
+	return err
+}
+
+func createRefFile(root, ref string, mft descriptor) error {
+	refpath := filepath.Join(root, "refs", ref)
+	f, err := os.Create(refpath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	refStr = strings.Replace(refStr, "<manifest_digest>", mft.Digest, -1)
+	refStr = strings.Replace(refStr, "<manifest_size>", strconv.FormatInt(mft.Size, 10), -1)
+	_, err = io.Copy(f, bytes.NewBuffer([]byte(refStr)))
+	return err
+}
+
+func createManifestFile(root, str string) (descriptor, error) {
+	name := filepath.Join(root, "blobs", "sha256", "test-manifest")
+	f, err := os.Create(name)
+	if err != nil {
+		return descriptor{}, err
+	}
+	defer f.Close()
+
+	_, err = io.Copy(f, bytes.NewBuffer([]byte(str)))
+	if err != nil {
+		return descriptor{}, err
+	}
+
+	return createHashedBlob(name)
+}
+
+func createConfigFile(root, config string) (descriptor, error) {
+	name := filepath.Join(root, "blobs", "sha256", "test-config")
+	f, err := os.Create(name)
+	if err != nil {
+		return descriptor{}, err
+	}
+	defer f.Close()
+
+	_, err = io.Copy(f, bytes.NewBuffer([]byte(config)))
+	if err != nil {
+		return descriptor{}, err
+	}
+
+	return createHashedBlob(name)
+}
+
+func createImageLayerFile(root string, list []tarContent) (descriptor, error) {
+	name := filepath.Join(root, "blobs", "sha256", "test-layer")
+	err := createTarBlob(name, list)
+	if err != nil {
+		return descriptor{}, err
+	}
+
+	desc, err := createHashedBlob(name)
+	if err != nil {
+		return descriptor{}, err
+	}
+
+	desc.MediaType = v1.MediaTypeImageLayer
+	return desc, nil
+}
+
+func createTarBlob(name string, list []tarContent) error {
+	file, err := os.Create(name)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	gzipWriter := gzip.NewWriter(file)
+	defer gzipWriter.Close()
+	tarWriter := tar.NewWriter(gzipWriter)
+	defer tarWriter.Close()
+
+	for _, content := range list {
+		if err = tarWriter.WriteHeader(content.header); err != nil {
+			return err
+		}
+		if _, err = io.Copy(tarWriter, bytes.NewReader(content.b)); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func createHashedBlob(name string) (descriptor, error) {
+	desc, err := newDescriptor(name)
+	if err != nil {
+		return descriptor{}, err
+	}
+
+	// Rename the file to hashed-digest name.
+	err = os.Rename(name, filepath.Join(filepath.Dir(name), desc.Digest))
+	if err != nil {
+		return descriptor{}, err
+	}
+
+	//Normalize the hashed digest.
+	desc.Digest = "sha256:" + desc.Digest
+
+	return desc, nil
+}
+
+func newDescriptor(name string) (descriptor, error) {
+	file, err := os.Open(name)
+	if err != nil {
+		return descriptor{}, err
+	}
+	defer file.Close()
+
+	// generate sha256 hash
+	hash := sha256.New()
+	size, err := io.Copy(hash, file)
+	if err != nil {
+		return descriptor{}, err
+	}
+
+	return descriptor{
+		Digest: fmt.Sprintf("%x", hash.Sum(nil)),
+		Size:   size,
+	}, nil
+}