cli: when migrating snapshot honor destination policies (#1433)

In particular this applies compression based on destination repository
policies.

By default ignore rules are disabled during migration to preserve all
files, but that can be optionally enabled using '--apply-ignore-rules'.

Fixes #1429

cli/command_snapshot_migrate.go

@@ -22,6 +22,7 @@ type commandSnapshotMigrate struct {
 	migrateOverwritePolicies bool
 	migrateLatestOnly        bool
 	migrateParallel          int
+	applyIgnoreRules         bool
 
 	svc advancedAppServices
 	out textOutput
@@ -36,6 +37,7 @@ func (c *commandSnapshotMigrate) setup(svc advancedAppServices, parent commandPa
 	cmd.Flag("overwrite-policies", "Overwrite policies").BoolVar(&c.migrateOverwritePolicies)
 	cmd.Flag("latest-only", "Only migrate the latest snapshot").BoolVar(&c.migrateLatestOnly)
 	cmd.Flag("parallel", "Number of sources to migrate in parallel").Default("1").IntVar(&c.migrateParallel)
+	cmd.Flag("apply-ignore-rules", "When migrating also apply current ignore rules").BoolVar(&c.applyIgnoreRules)
 	cmd.Action(svc.repositoryWriterAction(c.run))
 
 	c.svc = svc
@@ -269,7 +271,12 @@ func (c *commandSnapshotMigrate) migrateSingleSourceSnapshot(ctx context.Context
 		return err
 	}
 
-	var policyTree *policy.Tree
+	policyTree, err := policy.TreeForSource(ctx, destRepo, m.Source)
+	if err != nil {
+		return errors.Wrap(err, "error generating policy tree")
+	}
+
+	uploader.DisableIgnoreRules = !c.applyIgnoreRules
 
 	newm, err := uploader.Upload(ctx, sourceEntry, policyTree, m.Source, previous...)
 	if err != nil {

snapshot/snapshotfs/upload.go

@@ -70,6 +70,9 @@ type Uploader struct {
 	// How frequently to create checkpoint snapshot entries.
 	CheckpointInterval time.Duration
 
+	// When set to true, do not ignore any files, regardless of policy settings.
+	DisableIgnoreRules bool
+
 	repo repo.RepositoryWriter
 
 	// stats must be allocated on heap to enforce 64-bit alignment due to atomic access on ARM.
@@ -1206,6 +1209,10 @@ func (u *Uploader) Upload(
 }
 
 func (u *Uploader) wrapIgnorefs(entry fs.Directory, policyTree *policy.Tree) fs.Directory {
+	if u.DisableIgnoreRules {
+		return entry
+	}
+
 	return ignorefs.New(entry, policyTree, ignorefs.ReportIgnoredFiles(func(fname string, md fs.Entry) {
 		if md.IsDir() {
 			u.Progress.ExcludedDir(fname)

tests/end_to_end_test/snapshot_migrate_test.go

@@ -1,9 +1,15 @@
 package endtoend_test
 
 import (
+	"os"
 	"path/filepath"
 	"testing"
 
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+
+	"github.com/kopia/kopia/internal/testutil"
+	"github.com/kopia/kopia/snapshot"
 	"github.com/kopia/kopia/tests/testenv"
 )
 
@@ -16,6 +22,7 @@ func (s *formatSpecificTestSuite) TestSnapshotMigrate(t *testing.T) {
 	defer e.RunAndExpectSuccess(t, "repo", "disconnect")
 
 	e.RunAndExpectSuccess(t, "repo", "create", "filesystem", "--path", e.RepoDir)
+	e.RunAndExpectSuccess(t, "policy", "set", "--global", "--compression=pgzip")
 	e.RunAndExpectSuccess(t, "snapshot", "create", ".")
 
 	e.RunAndExpectSuccess(t, "snapshot", "create", sharedTestDataDir1)
@@ -28,19 +35,117 @@ func (s *formatSpecificTestSuite) TestSnapshotMigrate(t *testing.T) {
 	e.RunAndExpectSuccess(t, "snapshot", "create", sharedTestDataDir3)
 	e.RunAndExpectSuccess(t, "policy", "set", sharedTestDataDir3, "--keep-daily=88")
 
+	compressibleDir := testutil.TempDirectory(t)
+
+	for i := 0; i < 10; i++ {
+		require.NoError(t, writeCompressibleFile(filepath.Join(compressibleDir, uuid.NewString())))
+	}
+
+	e.RunAndExpectSuccess(t, "snapshot", "create", compressibleDir)
+
+	dirSize1 := mustGetTotalDirSize(t, e.RepoDir)
+
 	sourceSnapshotCount := len(e.RunAndExpectSuccess(t, "snapshot", "list", ".", "-a"))
 	sourcePolicyCount := len(e.RunAndExpectSuccess(t, "policy", "list"))
 
 	dstenv := testenv.NewCLITest(t, s.formatFlags, runner)
 
 	dstenv.RunAndExpectSuccess(t, "repo", "create", "filesystem", "--path", dstenv.RepoDir)
 
-	dstenv.RunAndExpectSuccess(t, "snapshot", "migrate", "--source-config", filepath.Join(e.ConfigDir, ".kopia.config"), "--all", "--parallel=5")
+	dstenv.RunAndExpectSuccess(t, "snapshot", "migrate", "--source-config", filepath.Join(e.ConfigDir, ".kopia.config"), "--all", "--parallel=5", "--overwrite-policies")
 	dstenv.RunAndVerifyOutputLineCount(t, sourceSnapshotCount, "snapshot", "list", ".", "-a")
 	dstenv.RunAndVerifyOutputLineCount(t, sourcePolicyCount, "policy", "list")
 
 	// migrate again, which should be a no-op, and should not create any more policies/snapshots
-	dstenv.RunAndExpectSuccess(t, "snapshot", "migrate", "--source-config", filepath.Join(e.ConfigDir, ".kopia.config"), "--all")
+	dstenv.RunAndExpectSuccess(t, "snapshot", "migrate", "--source-config", filepath.Join(e.ConfigDir, ".kopia.config"), "--all", "--overwrite-policies")
 	dstenv.RunAndVerifyOutputLineCount(t, sourceSnapshotCount, "snapshot", "list", ".", "-a")
 	dstenv.RunAndVerifyOutputLineCount(t, sourcePolicyCount, "policy", "list")
+
+	// make sure compression was applied during migration
+	dirSize2 := mustGetTotalDirSize(t, dstenv.RepoDir)
+
+	require.Less(t, dirSize2, dirSize1*110/100)
+}
+
+func (s *formatSpecificTestSuite) TestSnapshotMigrateWithIgnores(t *testing.T) {
+	t.Parallel()
+
+	runner := testenv.NewInProcRunner(t)
+	e := testenv.NewCLITest(t, s.formatFlags, runner)
+
+	defer e.RunAndExpectSuccess(t, "repo", "disconnect")
+
+	sd := testutil.TempDirectory(t)
+
+	require.NoError(t, os.WriteFile(filepath.Join(sd, "file1.txt"), []byte{1, 2, 3}, 0o666))
+	require.NoError(t, os.WriteFile(filepath.Join(sd, "file2.txt"), []byte{1, 2, 3}, 0o666))
+
+	e.RunAndExpectSuccess(t, "repo", "create", "filesystem", "--path", e.RepoDir)
+	e.RunAndExpectSuccess(t, "snapshot", "create", sd)
+
+	dstenv := testenv.NewCLITest(t, s.formatFlags, runner)
+	dstenv.RunAndExpectSuccess(t, "repo", "create", "filesystem", "--path", dstenv.RepoDir)
+
+	// now set policy to ignore file2.txt and migrate
+	dstenv.RunAndExpectSuccess(t, "policy", "set", sd, "--add-ignore", "file2.txt")
+	dstenv.RunAndExpectSuccess(t, "snapshot", "migrate", "--source-config", filepath.Join(e.ConfigDir, ".kopia.config"), "--all", "--apply-ignore-rules")
+
+	var manifests []snapshot.Manifest
+
+	testutil.MustParseJSONLines(t, dstenv.RunAndExpectSuccess(t, "snapshot", "list", "-a", sd, "--json"), &manifests)
+
+	if got, want := len(manifests), 1; got != want {
+		t.Fatalf("unexpected number of snapshots %v want %v", got, want)
+	}
+
+	lines := dstenv.RunAndExpectSuccess(t, "ls", string(manifests[0].RootObjectID()))
+
+	// make sure file2.txt was not migrated.
+	require.Contains(t, lines, "file1.txt")
+	require.NotContains(t, lines, "file2.txt")
+}
+
+func mustGetTotalDirSize(t *testing.T, dirpath string) int64 {
+	t.Helper()
+
+	ent, err := os.ReadDir(dirpath)
+	require.NoError(t, err)
+
+	var total int64
+
+	for _, e := range ent {
+		fi, err := e.Info()
+
+		require.NoError(t, err)
+
+		if !fi.IsDir() {
+			total += fi.Size()
+		} else {
+			total += mustGetTotalDirSize(t, filepath.Join(dirpath, e.Name()))
+		}
+	}
+
+	return total
+}
+
+func writeCompressibleFile(fname string) error {
+	f, err := os.Create(fname)
+	if err != nil {
+		return err
+	}
+
+	defer f.Close()
+
+	// 1000 x 64000
+	for i := 0; i < 1000; i++ {
+		val := uuid.NewString()
+
+		for j := 0; j < 100; j++ {
+			if _, err := f.WriteString(val); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
 }