Add tests for chunked pulls

Signed-off-by: Miloslav Trmač <[email protected]>

test/e2e/pull_chunked_test.go

@@ -0,0 +1,393 @@
+//go:build linux || freebsd
+
+package integration
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"slices"
+	"strings"
+
+	. "github.com/containers/podman/v5/test/utils"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	. "github.com/onsi/gomega/gexec"
+	"github.com/opencontainers/go-digest"
+	imgspecv1 "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+func pullChunkedTests() { // included in pull_test.go
+	if podmanTest.ImageCacheFS == "vfs" {
+		Skip("VFS does not support chunked pulls") // We could still test that we enforce DiffID correctness.
+	}
+	if os.Getenv("CI_DESIRED_COMPOSEFS") != "" {
+		// With convert_images, we use the partial pulls for all layers, and do not exercise the full pull code path.
+		Skip("The composefs configuration (with convert_images = true) interferes with this test's image ID expectations")
+	}
+	SkipIfRemote("(podman system reset) is required for this test")
+	if isRootless() {
+		err := podmanTest.RestoreArtifact(REGISTRY_IMAGE)
+		Expect(err).ToNot(HaveOccurred())
+	}
+	lock := GetPortLock(pullChunkedRegistryPort)
+	defer lock.Unlock()
+
+	pullChunkedRegistryPrefix := "docker://localhost:" + pullChunkedRegistryPort + "/"
+
+	imageDir := filepath.Join(tempdir, "images")
+	err := os.MkdirAll(imageDir, 0o700)
+	Expect(err).NotTo(HaveOccurred())
+
+	// Prepare test images.
+	pullChunkedStartRegistry()
+	chunkedNormal := &pullChunkedTestImage{
+		registryRef: pullChunkedRegistryPrefix + "chunked-normal",
+		dirPath:     filepath.Join(imageDir, "chunked-normal"),
+	}
+	podmanTest.PodmanExitCleanly("pull", "-q", ALPINE)
+	podmanTest.PodmanExitCleanly("push", "-q", "--tls-verify=false", "--force-compression", "--compression-format=zstd:chunked", ALPINE, chunkedNormal.registryRef)
+	skopeo := SystemExec("skopeo", []string{"copy", "-q", "--preserve-digests", "--all", "--src-tls-verify=false", chunkedNormal.registryRef, "dir:" + chunkedNormal.dirPath})
+	skopeo.WaitWithDefaultTimeout()
+	Expect(skopeo).Should(ExitCleanly())
+	jq := SystemExec("jq", []string{"-r", ".config.digest", filepath.Join(chunkedNormal.dirPath, "manifest.json")})
+	jq.WaitWithDefaultTimeout()
+	Expect(jq).Should(ExitCleanly())
+	cd, err := digest.Parse(jq.OutputToString())
+	Expect(err).NotTo(HaveOccurred())
+	chunkedNormal.configDigest = cd
+
+	schema1 := &pullChunkedTestImage{
+		registryRef:  pullChunkedRegistryPrefix + "schema1",
+		dirPath:      filepath.Join(imageDir, "schema1"),
+		configDigest: "",
+	}
+	skopeo = SystemExec("skopeo", []string{"copy", "-q", "--format=v2s1", "--dest-compress=true", "--dest-compress-format=gzip", "dir:" + chunkedNormal.dirPath, "dir:" + schema1.dirPath})
+	skopeo.WaitWithDefaultTimeout()
+	Expect(skopeo).Should(ExitCleanly())
+
+	createChunkedImage := func(name string, editDiffIDs func([]digest.Digest) []digest.Digest) *pullChunkedTestImage {
+		name = "chunked-" + name
+		res := pullChunkedTestImage{
+			registryRef: pullChunkedRegistryPrefix + name,
+			dirPath:     filepath.Join(imageDir, name),
+		}
+		cmd := SystemExec("cp", []string{"-a", chunkedNormal.dirPath, res.dirPath})
+		cmd.WaitWithDefaultTimeout()
+		Expect(cmd).Should(ExitCleanly())
+
+		configBytes, err := os.ReadFile(filepath.Join(chunkedNormal.dirPath, chunkedNormal.configDigest.Encoded()))
+		Expect(err).NotTo(HaveOccurred())
+		configBytes = editJSON(configBytes, func(config *imgspecv1.Image) {
+			config.RootFS.DiffIDs = editDiffIDs(config.RootFS.DiffIDs)
+		})
+		res.configDigest = digest.FromBytes(configBytes)
+		err = os.WriteFile(filepath.Join(res.dirPath, res.configDigest.Encoded()), configBytes, 0o600)
+		Expect(err).NotTo(HaveOccurred())
+
+		manifestBytes, err := os.ReadFile(filepath.Join(chunkedNormal.dirPath, "manifest.json"))
+		Expect(err).NotTo(HaveOccurred())
+		manifestBytes = editJSON(manifestBytes, func(manifest *imgspecv1.Manifest) {
+			manifest.Config.Digest = res.configDigest
+			manifest.Config.Size = int64(len(configBytes))
+		})
+		err = os.WriteFile(filepath.Join(res.dirPath, "manifest.json"), manifestBytes, 0o600)
+		Expect(err).NotTo(HaveOccurred())
+
+		return &res
+	}
+	createNonchunkedImage := func(name string, input *pullChunkedTestImage) *pullChunkedTestImage {
+		name = "nonchunked-" + name
+		res := pullChunkedTestImage{
+			registryRef:  pullChunkedRegistryPrefix + name,
+			dirPath:      filepath.Join(imageDir, name),
+			configDigest: input.configDigest,
+		}
+		cmd := SystemExec("cp", []string{"-a", input.dirPath, res.dirPath})
+		cmd.WaitWithDefaultTimeout()
+		Expect(cmd).Should(ExitCleanly())
+
+		manifestBytes, err := os.ReadFile(filepath.Join(input.dirPath, "manifest.json"))
+		Expect(err).NotTo(HaveOccurred())
+		manifestBytes = editJSON(manifestBytes, func(manifest *imgspecv1.Manifest) {
+			manifest.Layers = slices.Clone(manifest.Layers)
+			for i := range manifest.Layers {
+				delete(manifest.Layers[i].Annotations, "io.github.containers.zstd-chunked.manifest-checksum")
+			}
+		})
+		err = os.WriteFile(filepath.Join(res.dirPath, "manifest.json"), manifestBytes, 0o600)
+		Expect(err).NotTo(HaveOccurred())
+
+		return &res
+	}
+	chunkedMismatch := createChunkedImage("mismatch", func(diffIDs []digest.Digest) []digest.Digest {
+		modified := slices.Clone(diffIDs)
+		digestBytes, err := hex.DecodeString(diffIDs[0].Encoded())
+		Expect(err).NotTo(HaveOccurred())
+		digestBytes[len(digestBytes)-1] ^= 1
+		modified[0] = digest.NewDigestFromEncoded(diffIDs[0].Algorithm(), hex.EncodeToString(digestBytes))
+		return modified
+	})
+	chunkedMissing := createChunkedImage("missing", func(diffIDs []digest.Digest) []digest.Digest {
+		return nil
+	})
+	chunkedEmpty := createChunkedImage("empty", func(diffIDs []digest.Digest) []digest.Digest {
+		res := make([]digest.Digest, len(diffIDs))
+		for i := range res {
+			res[i] = ""
+		}
+		return res
+	})
+	nonchunkedNormal := createNonchunkedImage("normal", chunkedNormal)
+	nonchunkedMismatch := createNonchunkedImage("mismatch", chunkedMismatch)
+	nonchunkedMissing := createNonchunkedImage("missing", chunkedMissing)
+	nonchunkedEmpty := createNonchunkedImage("empty", chunkedEmpty)
+	pullChunkedStopRegistry()
+
+	// The actual test
+	for _, c := range []struct {
+		img             *pullChunkedTestImage
+		insecureStorage bool
+		fresh           pullChunkedExpectation
+		reuse           pullChunkedExpectation
+		onSuccess       []string
+		onFailure       []string
+	}{
+		// == Pulls of chunked images
+		{
+			img:   chunkedNormal,
+			fresh: pullChunkedExpectation{success: []string{"Created zstd:chunked differ for blob"}}, // Is a partial pull
+			reuse: pullChunkedExpectation{success: []string{"Skipping blob .*already present"}},
+		},
+		{
+			img: chunkedMismatch,
+			fresh: pullChunkedExpectation{failure: []string{
+				"Created zstd:chunked differ for blob", // Is a partial pull
+				"partial pull of blob.*uncompressed digest of layer.*is.*config claims",
+			}},
+			reuse: pullChunkedExpectation{failure: []string{"trying to reuse blob.*layer.*does not match config's DiffID"}},
+		},
+		{
+			img: chunkedMissing,
+			fresh: pullChunkedExpectation{success: []string{
+				"Failed to retrieve partial blob: DiffID value for layer .* is unknown or explicitly empty", // Partial pull rejected
+				"Detected compression format zstd", // Non-partial pull happens
+			}},
+			reuse: pullChunkedExpectation{success: []string{
+				"Not using TOC .* to look for layer reuse: DiffID value for layer .* is unknown or explicitly empty", // Partial pull reuse rejected
+				"Skipping blob .*already present", // Non-partial reuse happens
+			}},
+		},
+		{
+			img: chunkedEmpty,
+			fresh: pullChunkedExpectation{success: []string{
+				"Failed to retrieve partial blob: DiffID value for layer .* is unknown or explicitly empty", // Partial pull rejected
+				"Detected compression format zstd", // Non-partial pull happens
+			}},
+			reuse: pullChunkedExpectation{success: []string{
+				"Not using TOC .* to look for layer reuse: DiffID value for layer .* is unknown or explicitly empty", // Partial pull reuse rejected
+				"Skipping blob .*already present", // Non-partial reuse happens
+			}},
+		},
+		// == Pulls of images without zstd-chunked metadata (although the layer files are actually zstd:chunked, so blob digest match chunkedNormal and trigger reuse)
+		{
+			img: nonchunkedNormal,
+			fresh: pullChunkedExpectation{success: []string{
+				"Failed to retrieve partial blob: no TOC found and convert_images is not configured", // Partial pull not possible
+				"Detected compression format zstd",                                                   // Non-partial pull happens
+			}},
+			reuse: pullChunkedExpectation{success: []string{"Skipping blob .*already present"}},
+		},
+		{
+			img: nonchunkedMismatch,
+			fresh: pullChunkedExpectation{failure: []string{
+				"Failed to retrieve partial blob: no TOC found and convert_images is not configured", // Partial pull not possible
+				"Detected compression format zstd",                                                   // Non-partial pull happens
+				"writing blob: layer .* does not match config's DiffID",
+			}},
+			reuse: pullChunkedExpectation{failure: []string{"trying to reuse blob.*layer.*does not match config's DiffID"}},
+		},
+		{
+			img: nonchunkedMissing,
+			fresh: pullChunkedExpectation{success: []string{
+				"Failed to retrieve partial blob: no TOC found and convert_images is not configured", // Partial pull not possible
+				"Detected compression format zstd",                                                   // Non-partial pull happens
+			}},
+			reuse: pullChunkedExpectation{success: []string{"Skipping blob .*already present"}}, // Non-partial reuse happens
+		},
+		{
+			img: nonchunkedEmpty,
+			fresh: pullChunkedExpectation{success: []string{
+				"Failed to retrieve partial blob: no TOC found and convert_images is not configured", // Partial pull not possible
+				"Detected compression format zstd",                                                   // Non-partial pull happens
+			}},
+			reuse: pullChunkedExpectation{success: []string{"Skipping blob .*already present"}}, // Non-partial reuse happens
+		},
+		// == Pulls of chunked images with insecure_allow_unpredictable_image_contents
+		// NOTE: This tests current behavior, but we don't promise users that insecure_allow_unpredictable_image_contents is any faster
+		// nor that it sets any particular image IDs.
+		{
+			img:             chunkedNormal,
+			insecureStorage: true,
+			fresh: pullChunkedExpectation{success: []string{
+				"Created zstd:chunked differ for blob", // Is a partial pull
+				"Ordinary storage image ID .*; a layer was looked up by TOC, so using image ID .*",
+			}},
+			reuse: pullChunkedExpectation{success: []string{
+				"Skipping blob .*already present",
+				"Ordinary storage image ID .*; a layer was looked up by TOC, so using image ID .*",
+			}},
+		},
+		{
+			// WARNING: It happens to be the case that with insecure_allow_unpredictable_image_contents , images with non-matching DiffIDs
+			// can be pulled in these situations.
+			// WE ARE MAKING NO PROMISES THAT THEY WILL WORK. The images are invalid and need to be fixed.
+			// Today, in other situations (e.g. after pulling nonchunkedNormal), c/image will know the uncompressed digest despite insecure_allow_unpredictable_image_contents,
+			// and reject the image as not matching the config.
+			// As implementations change, the conditions when images with invalid DiffIDs will / will not work may also change, without
+			// notice.
+			img:             chunkedMismatch,
+			insecureStorage: true,
+			fresh: pullChunkedExpectation{success: []string{
+				"Created zstd:chunked differ for blob", // Is a partial pull
+				"Ordinary storage image ID .*; a layer was looked up by TOC, so using image ID .*",
+			}},
+			reuse: pullChunkedExpectation{success: []string{
+				"Skipping blob .*already present",
+				"Ordinary storage image ID .*; a layer was looked up by TOC, so using image ID .*",
+			}},
+		},
+		{
+			img:             chunkedMissing,
+			insecureStorage: true,
+			fresh: pullChunkedExpectation{success: []string{
+				"Failed to retrieve partial blob: DiffID value for layer .* is unknown or explicitly empty", // Partial pull rejected (the storage option does not actually make a difference)
+				"Detected compression format zstd", // Non-partial pull happens
+			}},
+			reuse: pullChunkedExpectation{success: []string{
+				"Not using TOC .* to look for layer reuse: DiffID value for layer .* is unknown or explicitly empty", // Partial pull reuse rejected (the storage option does not actually make a difference)
+				"Skipping blob .*already present", // Non-partial reuse happens
+			}},
+		},
+		{
+			img:             chunkedEmpty,
+			insecureStorage: true,
+			fresh: pullChunkedExpectation{success: []string{
+				"Failed to retrieve partial blob: DiffID value for layer .* is unknown or explicitly empty", // Partial pull rejected (the storage option does not actually make a difference)
+				"Detected compression format zstd", // Non-partial pull happens
+			}},
+			reuse: pullChunkedExpectation{success: []string{
+				"Not using TOC .* to look for layer reuse: DiffID value for layer .* is unknown or explicitly empty", // Partial pull reuse rejected (the storage option does not actually make a difference)
+				"Skipping blob .*already present", // Non-partial reuse happens
+			}},
+		},
+		// Schema1
+		{
+			img: schema1,
+			fresh: pullChunkedExpectation{success: []string{
+				"Failed to retrieve partial blob: no TOC found and convert_images is not configured", // Partial pull not possible
+				"Detected compression format gzip",                                                   // Non-partial pull happens
+			}},
+			reuse: pullChunkedExpectation{success: []string{"Skipping blob .*already present"}},
+		},
+		// == No tests of estargz images (Podman can’t create them)
+	} {
+		if c.insecureStorage {
+			GinkgoWriter.Printf("===\n===Testing %s with insecure config\n===\n", c.img.registryRef)
+		} else {
+			GinkgoWriter.Printf("===\n===Testing %s\n===\n", c.img.registryRef)
+		}
+
+		// Do each test with a clean slate: no layer metadata known, no blob info cache.
+		// Annoyingly, we have to re-start and re-populate the registry as well.
+		podmanTest.PodmanExitCleanly("system", "reset", "-f")
+
+		pullChunkedStartRegistry()
+		c.img.push()
+		chunkedNormal.push()
+
+		// Test fresh pull
+		c.fresh.testPull(c.img, c.insecureStorage)
+
+		podmanTest.PodmanExitCleanly("--pull-option=enable_partial_images=true", fmt.Sprintf("--pull-option=insecure_allow_unpredictable_image_contents=%v", c.insecureStorage),
+			"pull", "-q", "--tls-verify=false", chunkedNormal.registryRef)
+
+		// Test pull after chunked layers are already known, to trigger the layer reuse code
+		c.reuse.testPull(c.img, c.insecureStorage)
+
+		pullChunkedStopRegistry()
+	}
+}
+
+const pullChunkedRegistryPort = "5013"
+
+// pullChunkedStartRegistry creates a registry listening at pullChunkedRegistryPort within the current Podman environment.
+func pullChunkedStartRegistry() {
+	podmanTest.PodmanExitCleanly("run", "-d", "--name", "registry", "--rm", "-p", pullChunkedRegistryPort+":5000", "-e", "REGISTRY_COMPATIBILITY_SCHEMA1_ENABLED=true", REGISTRY_IMAGE, "/entrypoint.sh", "/etc/docker/registry/config.yml")
+	if !WaitContainerReady(podmanTest, "registry", "listening on", 20, 1) {
+		Fail("Cannot start docker registry.")
+	}
+}
+
+// pullChunkedStopRegistry stops a registry started by pullChunkedStartRegistry.
+func pullChunkedStopRegistry() {
+	podmanTest.PodmanExitCleanly("stop", "registry")
+}
+
+// pullChunkedTestImage centralizes data about a single test image in pullChunkedTests.
+type pullChunkedTestImage struct {
+	registryRef, dirPath string
+	configDigest         digest.Digest // "" for a schema1 image
+}
+
+// push copies the image from dirPath to registryRef.
+func (img *pullChunkedTestImage) push() {
+	skopeo := SystemExec("skopeo", []string{"copy", "-q", fmt.Sprintf("--preserve-digests=%v", img.configDigest != ""), "--all", "--dest-tls-verify=false", "dir:" + img.dirPath, img.registryRef})
+	skopeo.WaitWithDefaultTimeout()
+	Expect(skopeo).Should(ExitCleanly())
+}
+
+// pullChunkedExpectations records the expected output of a single "podman pull" command.
+type pullChunkedExpectation struct {
+	success []string // Expected debug log strings; should succeed if != nil
+	failure []string // Expected debug log strings; should fail if != nil
+}
+
+// testPull performs one pull
+func (expectation *pullChunkedExpectation) testPull(image *pullChunkedTestImage, insecureStorage bool) {
+	session := podmanTest.Podman([]string{"--log-level=debug", "--pull-option=enable_partial_images=true", fmt.Sprintf("--pull-option=insecure_allow_unpredictable_image_contents=%v", insecureStorage),
+		"pull", "--tls-verify=false", image.registryRef})
+	session.WaitWithDefaultTimeout()
+	GinkgoWriter.Printf("Pull exit code: %v\n", session.ExitCode())
+	log := session.ErrorToString()
+	if expectation.success != nil {
+		Expect(session).Should(Exit(0))
+		for _, s := range expectation.success {
+			Expect(regexp.MatchString(".*"+s+".*", log)).To(BeTrue(), s)
+		}
+
+		if image.configDigest != "" && !insecureStorage {
+			s2 := podmanTest.PodmanExitCleanly("image", "inspect", "--format={{.ID}}", strings.TrimPrefix(image.registryRef, "docker://"))
+			Expect(s2.OutputToString()).Should(Equal(image.configDigest.Encoded()))
+		}
+	} else {
+		Expect(session).Should(Exit(125))
+		for _, s := range expectation.failure {
+			Expect(regexp.MatchString(".*"+s+".*", log)).To(BeTrue(), s)
+		}
+	}
+}
+
+// editJSON modifies a JSON-formatted input using the provided edit function.
+func editJSON[T any](input []byte, edit func(*T)) []byte {
+	var value T
+	err = json.Unmarshal(input, &value)
+	Expect(err).NotTo(HaveOccurred())
+	edit(&value)
+	res, err := json.Marshal(value)
+	Expect(err).NotTo(HaveOccurred())
+	return res
+}