Update will cleanup unneeded artifacts.

CHANGELOG.next.asciidoc

@@ -111,6 +111,7 @@
 - Allow the - char to appear as part of variable names in eql expressions. {issue}709[709] {pull}710[710]
 - Allow the / char in variable names in eql and transpiler. {issue}715[715] {pull}718[718]
 - Fix data duplication for standalone agent on Kubernetes using the default manifest {issue-beats}31512[31512] {pull}742[742]
+- Agent updates will clean up unneeded artifacts. {issue}693[693] {issue}694[694] {pull}752[752]
 
 ==== New features
 

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

@@ -0,0 +1,49 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License;
+// you may not use this file except in compliance with the Elastic License.
+
+package upgrade
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/elastic/elastic-agent/internal/pkg/agent/application/paths"
+)
+
+// preUpgradeCleanup will remove files that do not have the passed version number from the downloads directory.
+func preUpgradeCleanup(version string) error {
+	files, err := os.ReadDir(paths.Downloads())
+	if err != nil {
+		return err
+	}
+	for _, file := range files {
+		if file.IsDir() {
+			continue
+		}
+		if !strings.Contains(file.Name(), version) {
+			if err := os.Remove(filepath.Join(paths.Downloads(), file.Name())); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// cleanAllDownloads will remove all files from the downloads directory
+func cleanAllDownloads() error {
+	files, err := os.ReadDir(paths.Downloads())
+	if err != nil {
+		return err
+	}
+	for _, file := range files {
+		if file.IsDir() {
+			continue
+		}
+		if err := os.Remove(filepath.Join(paths.Downloads(), file.Name())); err != nil {
+			return err
+		}
+	}
+	return nil
+}

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

@@ -0,0 +1,61 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License;
+// you may not use this file except in compliance with the Elastic License.
+
+package upgrade
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/elastic/elastic-agent/internal/pkg/agent/application/paths"
+
+	"github.com/stretchr/testify/require"
+)
+
+func setupDir(t *testing.T) {
+	t.Helper()
+	dir := t.TempDir()
+	paths.SetDownloads(dir)
+
+	err := os.WriteFile(filepath.Join(dir, "test-8.3.0-file"), []byte("hello, world!"), 0600)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = os.WriteFile(filepath.Join(dir, "test-8.4.0-file"), []byte("hello, world!"), 0600)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = os.WriteFile(filepath.Join(dir, "test-8.5.0-file"), []byte("hello, world!"), 0600)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = os.WriteFile(filepath.Join(dir, "test-hash-file"), []byte("hello, world!"), 0600)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPreUpgradeCleanup(t *testing.T) {
+	setupDir(t)
+	err := preUpgradeCleanup("8.4.0")
+	require.NoError(t, err)
+
+	files, err := os.ReadDir(paths.Downloads())
+	require.NoError(t, err)
+	require.Len(t, files, 1)
+	require.Equal(t, "test-8.4.0-file", files[0].Name())
+	fi, err := files[0].Info()
+	require.NoError(t, err)
+	require.Greater(t, fi.Size(), int64(0))
+}
+
+func TestCleanAllDownloads(t *testing.T) {
+	setupDir(t)
+	err := cleanAllDownloads()
+	require.NoError(t, err)
+	files, err := os.ReadDir(paths.Downloads())
+	require.NoError(t, err)
+	require.Len(t, files, 0)
+}

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

@@ -126,6 +126,11 @@ func (u *Upgrader) Upgrade(ctx context.Context, a Action, reexecNow bool) (_ ree
 				"running under control of the systems supervisor")
 	}
 
+	err = preUpgradeCleanup(a.Version())
+	if err != nil {
+		u.log.Errorf("Unable to clean downloads dir %q before update: %v", paths.Downloads(), err)
+	}
+
 	if u.caps != nil {
 		if _, err := u.caps.Apply(a); errors.Is(err, capabilities.ErrBlocked) {
 			return nil, nil
@@ -137,6 +142,11 @@ func (u *Upgrader) Upgrade(ctx context.Context, a Action, reexecNow bool) (_ ree
 	sourceURI := u.sourceURI(a.SourceURI())
 	archivePath, err := u.downloadArtifact(ctx, a.Version(), sourceURI)
 	if err != nil {
+		// Run the same preUpgradeCleanup task to get rid of any newly downloaded files
+		// This may have an issue if users are upgrading to the same version number.
+		if dErr := preUpgradeCleanup(a.Version()); dErr != nil {
+			u.log.Errorf("Unable to remove file after verification failure: %v", dErr)
+		}
 		return nil, err
 	}
 
@@ -184,6 +194,13 @@ func (u *Upgrader) Upgrade(ctx context.Context, a Action, reexecNow bool) (_ ree
 		return nil, nil
 	}
 
+	// Clean everything from the downloads dir
+	// If we wanted to be a bit simpler we could call os.RemoveAll to remove the dir + children
+	err = cleanAllDownloads()
+	if err != nil {
+		u.log.Errorf("Unable to clean downloads dir %q after update: %v", paths.Downloads(), err)
+	}
+
 	return cb, nil
 }