[8.19] (backport #9386) Enhancement/5235 upgrade cleans up downloads and extracted agent (#10037)

* Enhancement/5235 upgrade cleans up downloads and extracted agent (#9386)

* enhancement(5235): added comments describing updates in error handling. returning path in error cases if the download is completed

* enhancement(5235): added wrapper var for verifier
constructor in download step to improve testability

* enhancement(5235): added test for downloadArtifact
verifier errors

* enhancement(5235): addded cleanupPaths slice. added deferred call to remove paths in the cleanupPaths slice

* enhancement(5235): add archive and hash path to cleanup paths after artifact download

* enhancement(5235): update error handling after unpack. add new versioned home to cleanup paths

enhancement(5235): move newHome declaration

* enhancement(5235): added upgrade cleanup test

* enhancement(5235): added changelog fragment

enhancement(5235): updated changelog fragment

* enhancement(5235): fix errors in step_download after rebase

* enhancement(5235): fix error in step_download_test after rebase

* enhancement(5235): refactor disk space error check and path cleanup into one deferred call

* enhancement(5235): refactored verifier factory and updated relevant download tests

* enhancement(5235): removed separate test for cleanup, added cleanup checks in error handling test

* enhancement(5235): changed function name in verifier

* enhancement(5235): using AddHashExtension instead of hard coded hash extension string in upgrader

(cherry picked from commit ab23962)

# Conflicts:
#	internal/pkg/agent/application/upgrade/upgrade.go
#	internal/pkg/agent/application/upgrade/upgrade_test.go

* resolved merge conflicts

---------

Co-authored-by: Kaan Yalti <[email protected]>

Author: mergify[bot]

changelog/fragments/1755268130-cleanup-downloads-directory-and-the-new-versioned-home-if-upgrade-fails.yaml

@@ -0,0 +1,32 @@
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: enhancement
+
+# Change summary; a 80ish characters long description of the change.
+summary: agent cleans up downloads directory and the new versioned home if upgrade fails
+
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# NOTE: This field will be rendered only for breaking-change and known-issue kinds at the moment.
+#description:
+
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: "elastic-agent"
+
+# PR URL; optional; the PR number that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+pr: https://github.com/elastic/elastic-agent/pull/9386
+
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+issue: https://github.com/elastic/elastic-agent/issues/5235

internal/pkg/agent/application/upgrade/artifact/download/verifier.go

@@ -106,12 +106,12 @@ func VerifySHA512HashWithCleanup(log infoWarnLogger, filename string) error {
 			}
 		} else if err != nil && !errors.Is(err, os.ErrNotExist) {
 			// it's not a simple hash mismatch, probably something is wrong with the hash file
-			hashFileName := getHashFileName(filename)
+			hashFileName := AddHashExtension(filename)
 			hashFileBytes, readErr := os.ReadFile(hashFileName)
 			if readErr != nil {
-				log.Warnf("error verifying the package using hash file %q, unable do read contents for logging: %v", getHashFileName(filename), readErr)
+				log.Warnf("error verifying the package using hash file %q, unable do read contents for logging: %v", AddHashExtension(filename), readErr)
 			} else {
-				log.Warnf("error verifying the package using hash file %q, contents: %q", getHashFileName(filename), string(hashFileBytes))
+				log.Warnf("error verifying the package using hash file %q, contents: %q", AddHashExtension(filename), string(hashFileBytes))
 			}
 		}
 
@@ -121,20 +121,20 @@ func VerifySHA512HashWithCleanup(log infoWarnLogger, filename string) error {
 	return nil
 }
 
-func getHashFileName(filename string) string {
+func AddHashExtension(file string) string {
 	const hashFileExt = ".sha512"
-	if strings.HasSuffix(filename, hashFileExt) {
-		return filename
+	if strings.HasSuffix(file, hashFileExt) {
+		return file
 	}
-	return filename + hashFileExt
+	return file + hashFileExt
 }
 
 // VerifySHA512Hash checks that a sidecar file containing a sha512 checksum
 // exists and that the checksum in the sidecar file matches the checksum of
 // the file. It returns an error if validation fails.
 func VerifySHA512Hash(filename string) error {
 	hasher := sha512.New()
-	checksumFileName := getHashFileName(filename)
+	checksumFileName := AddHashExtension(filename)
 	return VerifyChecksum(hasher, filename, checksumFileName)
 }
 

internal/pkg/agent/application/upgrade/step_download.go

@@ -41,16 +41,21 @@ type downloaderFactory func(*agtversion.ParsedSemVer, *logger.Logger, *artifact.
 
 type downloader func(context.Context, downloaderFactory, *agtversion.ParsedSemVer, *artifact.Config, *details.Details) (string, error)
 
+// abstraction for testability for newVerifier
+type verifierFactory func(*agtversion.ParsedSemVer, *logger.Logger, *artifact.Config) (download.Verifier, error)
+
 type artifactDownloader struct {
 	log            *logger.Logger
 	settings       *artifact.Config
 	fleetServerURI string
+	newVerifier    verifierFactory
 }
 
 func newArtifactDownloader(settings *artifact.Config, log *logger.Logger) *artifactDownloader {
 	return &artifactDownloader{
-		log:      log,
-		settings: settings,
+		log:         log,
+		settings:    settings,
+		newVerifier: newVerifier,
 	}
 }
 
@@ -123,19 +128,21 @@ func (a *artifactDownloader) downloadArtifact(ctx context.Context, parsedVersion
 		return "", fmt.Errorf("failed download of agent binary: %w", err)
 	}
 
+	// If there are errors in the following steps, we return the path so that we
+	// can cleanup the downloaded files.
 	if skipVerifyOverride {
 		return path, nil
 	}
 
 	if verifier == nil {
-		verifier, err = newVerifier(parsedVersion, a.log, &settings)
+		verifier, err = a.newVerifier(parsedVersion, a.log, &settings)
 		if err != nil {
-			return "", errors.New(err, "initiating verifier")
+			return path, errors.New(err, "initiating verifier")
 		}
 	}
 
 	if err := verifier.Verify(ctx, agentArtifact, *parsedVersion, skipDefaultPgp, pgpBytes...); err != nil {
-		return "", errors.New(err, "failed verification of agent binary")
+		return path, errors.New(err, "failed verification of agent binary")
 	}
 	return path, nil
 }

internal/pkg/agent/application/upgrade/step_download_test.go

@@ -8,13 +8,16 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"net/http"
+	"net/http/httptest"
 	"strings"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/require"
 
 	"github.com/elastic/elastic-agent-libs/transport/httpcommon"
+	"github.com/elastic/elastic-agent/internal/pkg/agent/application/paths"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/upgrade/artifact"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/upgrade/artifact/download"
 	downloadErrors "github.com/elastic/elastic-agent/internal/pkg/agent/application/upgrade/artifact/download/errors"
@@ -303,6 +306,86 @@ func TestDownloadWithRetries(t *testing.T) {
 	})
 }
 
+type mockVerifier struct {
+	called      bool
+	returnError error
+}
+
+func (mv *mockVerifier) Name() string {
+	return ""
+}
+
+func (mv *mockVerifier) Verify(ctx context.Context, a artifact.Artifact, version agtversion.ParsedSemVer, skipDefaultPgp bool, pgpBytes ...string) error {
+	mv.called = true
+	return mv.returnError
+}
+
+func TestDownloadArtifact(t *testing.T) {
+	testLogger, _ := loggertest.New("TestDownloadArtifact")
+	tempConfig := &artifact.Config{} // used only to get os and arch, runtime.GOARCH returns amd64 which is not a valid arch when used in GetArtifactName
+
+	parsedVersion, err := agtversion.ParseVersion("8.9.0")
+	require.NoError(t, err)
+
+	upgradeDeatils := details.NewDetails(parsedVersion.String(), details.StateRequested, "")
+
+	mockContent := []byte("mock content")
+
+	testServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		_, err := w.Write(mockContent)
+		require.NoError(t, err)
+	}))
+	defer testServer.Close()
+
+	testError := errors.New("test error")
+
+	type testCase struct {
+		mockNewVerifierFactory verifierFactory
+		expectedError          error
+	}
+
+	testCases := map[string]testCase{
+		"should return path if verifier constructor fails": {
+			mockNewVerifierFactory: func(version *agtversion.ParsedSemVer, log *logger.Logger, settings *artifact.Config) (download.Verifier, error) {
+				return nil, testError
+			},
+			expectedError: testError,
+		},
+		"should return path if verifier fails": {
+			mockNewVerifierFactory: func(version *agtversion.ParsedSemVer, log *logger.Logger, settings *artifact.Config) (download.Verifier, error) {
+				return &mockVerifier{returnError: testError}, nil
+			},
+			expectedError: testError,
+		},
+	}
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			paths.SetTop(t.TempDir())
+
+			artifactPath, err := artifact.GetArtifactPath(agentArtifact, *parsedVersion, tempConfig.OS(), tempConfig.Arch(), paths.Downloads())
+			require.NoError(t, err)
+
+			settings := artifact.Config{
+				RetrySleepInitDuration: 20 * time.Millisecond,
+				HTTPTransportSettings: httpcommon.HTTPTransportSettings{
+					Timeout: 2 * time.Second,
+				},
+				SourceURI:       testServer.URL,
+				TargetDirectory: paths.Downloads(),
+			}
+
+			a := newArtifactDownloader(&settings, testLogger)
+			a.newVerifier = tc.mockNewVerifierFactory
+
+			path, err := a.downloadArtifact(t.Context(), parsedVersion, testServer.URL, upgradeDeatils, false, true)
+			require.ErrorIs(t, err, tc.expectedError)
+			require.Equal(t, artifactPath, path)
+		})
+	}
+}
+
 // mockUpgradeDetails returns a *details.Details value that has an observer registered on it for inspecting
 // certain properties of the object being set and unset.  It also returns:
 // - a *time.Time value, which will be not nil if Metadata.RetryUntil is set on the mock value,

internal/pkg/agent/application/upgrade/upgrade.go

@@ -23,6 +23,7 @@ import (
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/paths"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/reexec"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/upgrade/artifact"
+	"github.com/elastic/elastic-agent/internal/pkg/agent/application/upgrade/artifact/download"
 	upgradeErrors "github.com/elastic/elastic-agent/internal/pkg/agent/application/upgrade/artifact/download/errors"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/application/upgrade/details"
 	"github.com/elastic/elastic-agent/internal/pkg/agent/configuration"
@@ -241,14 +242,23 @@ func checkUpgrade(log *logger.Logger, currentVersion, newVersion agentVersion, m
 // Upgrade upgrades running agent, function returns shutdown callback that must be called by reexec.
 func (u *Upgrader) Upgrade(ctx context.Context, version string, sourceURI string, action *fleetapi.ActionUpgrade, det *details.Details, skipVerifyOverride bool, skipDefaultPgp bool, pgpBytes ...string) (_ reexec.ShutdownCallbackFn, err error) {
 	u.log.Infow("Upgrading agent", "version", version, "source_uri", sourceURI)
-
+	cleanupPaths := []string{}
 	defer func() {
 		if err != nil {
 			// Add the disk space error to the error chain if it is a disk space error
 			// so that we can use errors.Is to check for it
 			if u.isDiskSpaceErrorFunc(err) {
 				err = goerrors.Join(err, upgradeErrors.ErrInsufficientDiskSpace)
 			}
+			// If there is an error, we need to clean up downloads and any
+			// extracted agent files.
+			for _, path := range cleanupPaths {
+				rmErr := os.RemoveAll(path)
+				if rmErr != nil {
+					u.log.Errorw("error removing path during upgrade cleanup", "error.message", rmErr, "path", path)
+					err = goerrors.Join(err, rmErr)
+				}
+			}
 		}
 	}()
 
@@ -293,6 +303,15 @@ func (u *Upgrader) Upgrade(ctx context.Context, version string, sourceURI string
 	}
 
 	archivePath, err := u.artifactDownloader.downloadArtifact(ctx, parsedVersion, sourceURI, det, skipVerifyOverride, skipDefaultPgp, pgpBytes...)
+
+	// If the artifactPath is not empty, then the artifact was downloaded.
+	// There may still be an error in the download process, so we need to add
+	// the archive and hash path to the cleanup slice.
+	if archivePath != "" {
+		archiveHashPath := download.AddHashExtension(archivePath)
+		cleanupPaths = append(cleanupPaths, archivePath, archiveHashPath)
+	}
+
 	if err != nil {
 		// Run the same pre-upgrade cleanup task to get rid of any newly downloaded files
 		// This may have an issue if users are upgrading to the same version number.
@@ -317,7 +336,22 @@ func (u *Upgrader) Upgrade(ctx context.Context, version string, sourceURI string
 
 	u.log.Infow("Unpacking agent package", "version", newVersion)
 
+	// Nice to have: add check that no archive files end up in the current versioned home
 	unpackRes, err := u.unpacker.unpack(version, archivePath, paths.Data())
+
+	// If VersionedHome is empty then unpack has not started unpacking the
+	// archive yet. There's nothing to clean up. Return the error.
+	if unpackRes.VersionedHome == "" {
+		return nil, goerrors.Join(err, fmt.Errorf("versionedhome is empty: %v", unpackRes))
+	}
+
+	// If VersionedHome is not empty, it means that the unpack function has
+	// started extracting the archive. It may have failed while extracting.
+	// Setup newHome to be cleanedup.
+	newHome := filepath.Join(paths.Top(), unpackRes.VersionedHome)
+
+	cleanupPaths = append(cleanupPaths, newHome)
+
 	if err != nil {
 		return nil, err
 	}
@@ -327,12 +361,6 @@ func (u *Upgrader) Upgrade(ctx context.Context, version string, sourceURI string
 		return nil, errors.New("unknown hash")
 	}
 
-	if unpackRes.VersionedHome == "" {
-		return nil, fmt.Errorf("versionedhome is empty: %v", unpackRes)
-	}
-
-	newHome := filepath.Join(paths.Top(), unpackRes.VersionedHome)
-
 	if err := u.copyActionStore(u.log, newHome); err != nil {
 		return nil, fmt.Errorf("failed to copy action store: %w", err)
 	}