Merge pull request #863 from carvel-dev/memory-optimisation

Memory optimization
carvel-dev · Jan 19, 2024 · 90412c7 · 90412c7
2 parents b494b67 + 9f70c5d
commit 90412c7
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Showing 23 changed files with 495 additions and 90 deletions.
diff --git a/go.mod b/go.mod
@@ -6,10 +6,10 @@ require (
 	github.com/cppforlife/cobrautil v0.0.0-20221130162803-acdfead391ef
 	github.com/cppforlife/color v1.9.1-0.20200716202919-6706ac40b835
 	github.com/cppforlife/go-cli-ui v0.0.0-20220425131040-94f26b16bc14
-	github.com/cppforlife/go-patch v0.2.0
+	github.com/cppforlife/go-patch v0.0.0-20240118020416-2147782e467b
 	github.com/google/go-cmp v0.6.0
 	github.com/hashicorp/go-version v1.6.0
-	github.com/k14s/difflib v0.0.0-20201117154628-0c031775bf57
+	github.com/k14s/difflib v0.0.0-20240118055029-596a7a5585c3
 	github.com/k14s/ytt v0.36.0
 	github.com/mitchellh/go-wordwrap v1.0.1
 	github.com/spf13/cobra v1.7.0

diff --git a/go.sum b/go.sum
@@ -42,8 +42,8 @@ github.com/cppforlife/color v1.9.1-0.20200716202919-6706ac40b835/go.mod h1:dYeVs
 github.com/cppforlife/go-cli-ui v0.0.0-20200505234325-512793797f05/go.mod h1:I0qrzCmuPWYI6kAOvkllYjaW2aovclWbJ96+v+YyHb0=
 github.com/cppforlife/go-cli-ui v0.0.0-20220425131040-94f26b16bc14 h1:MjRdR01xh0sfkeS3OOBv+MYkYsrbHuTDc4rfBnVdFaI=
 github.com/cppforlife/go-cli-ui v0.0.0-20220425131040-94f26b16bc14/go.mod h1:AlgTssDlstr4mf92TR4DPITLfl5+7wEY4cKStCmeeto=
-github.com/cppforlife/go-patch v0.2.0 h1:Y14MnCQjDlbw7WXT4k+u6DPAA9XnygN4BfrSpI/19RU=
-github.com/cppforlife/go-patch v0.2.0/go.mod h1:67a7aIi94FHDZdoeGSJRRFDp66l9MhaAG1yGxpUoFD8=
+github.com/cppforlife/go-patch v0.0.0-20240118020416-2147782e467b h1:+8LQctLhaj+63L/37l8IK/5Q3odN6RzWlglonUwrKok=
+github.com/cppforlife/go-patch v0.0.0-20240118020416-2147782e467b/go.mod h1:67a7aIi94FHDZdoeGSJRRFDp66l9MhaAG1yGxpUoFD8=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.0/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
@@ -169,8 +169,9 @@ github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHm
 github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
-github.com/k14s/difflib v0.0.0-20201117154628-0c031775bf57 h1:CwBRArr+BWBopnUJhDjJw86rPL/jGbEjfHWKzTasSqE=
 github.com/k14s/difflib v0.0.0-20201117154628-0c031775bf57/go.mod h1:B0xN2MiNBGWOWi9CcfAo9LBI8IU4J1utlbOIJCsmKr4=
+github.com/k14s/difflib v0.0.0-20240118055029-596a7a5585c3 h1:q2ikACDbDDbyUcN9JkDcNMGhIx1EBRkctAsPZMr35qM=
+github.com/k14s/difflib v0.0.0-20240118055029-596a7a5585c3/go.mod h1:B0xN2MiNBGWOWi9CcfAo9LBI8IU4J1utlbOIJCsmKr4=
 github.com/k14s/starlark-go v0.0.0-20200720175618-3a5c849cc368 h1:4bcRTTSx+LKSxMWibIwzHnDNmaN1x52oEpvnjCy+8vk=
 github.com/k14s/starlark-go v0.0.0-20200720175618-3a5c849cc368/go.mod h1:lKGj1op99m4GtQISxoD2t+K+WO/q2NzEPKvfXFQfbCA=
 github.com/k14s/ytt v0.36.0 h1:ERr7q+r3ziYJv91fvTx2b76d1MIo3SI/EsAS01WU+Zo=

diff --git a/pkg/kapp/cmd/app/delete.go b/pkg/kapp/cmd/app/delete.go
@@ -233,7 +233,7 @@ func (o *DeleteOptions) calculateAndPresentChanges(existingResources []ctlres.Re
 	)
 
 	{ // Figure out changes for X existing resources -> 0 new resources
-		changeFactory := ctldiff.NewChangeFactory(nil, nil, nil)
+		changeFactory := ctldiff.NewChangeFactory(nil, nil, nil, ctldiff.ChangeOpts{o.DiffFlags.AnchoredDiff})
 		changeSetFactory := ctldiff.NewChangeSetFactory(o.DiffFlags.ChangeSetOpts, changeFactory)
 
 		changes, err := changeSetFactory.New(existingResources, nil).Calculate()

diff --git a/pkg/kapp/cmd/app/deploy.go b/pkg/kapp/cmd/app/deploy.go
@@ -410,7 +410,7 @@ func (o *DeployOptions) calculateAndPresentChanges(existingResources,
 	var clusterChangeSet ctlcap.ClusterChangeSet
 
 	{ // Figure out changes for X existing resources -> X new resources
-		changeFactory := ctldiff.NewChangeFactory(conf.RebaseMods(), conf.DiffAgainstLastAppliedFieldExclusionMods(), conf.DiffAgainstExistingFieldExclusionMods())
+		changeFactory := ctldiff.NewChangeFactory(conf.RebaseMods(), conf.DiffAgainstLastAppliedFieldExclusionMods(), conf.DiffAgainstExistingFieldExclusionMods(), ctldiff.ChangeOpts{o.DiffFlags.AnchoredDiff})
 		changeSetFactory := ctldiff.NewChangeSetFactory(o.DiffFlags.ChangeSetOpts, changeFactory)
 
 		err := ctldiff.NewRenewableResources(existingResources, newResources).Prepare()

diff --git a/pkg/kapp/cmd/tools/diff.go b/pkg/kapp/cmd/tools/diff.go
@@ -53,7 +53,7 @@ func (o *DiffOptions) Run() error {
 		return err
 	}
 
-	changeFactory := ctldiff.NewChangeFactory(nil, nil, nil)
+	changeFactory := ctldiff.NewChangeFactory(nil, nil, nil, ctldiff.ChangeOpts{o.DiffFlags.AnchoredDiff})
 
 	changes, err := ctldiff.NewChangeSet(existingResources, newResources, o.DiffFlags.ChangeSetOpts, changeFactory).Calculate()
 	if err != nil {

diff --git a/pkg/kapp/cmd/tools/diff_flags.go b/pkg/kapp/cmd/tools/diff_flags.go
@@ -17,6 +17,8 @@ type DiffFlags struct {
 	Run        bool
 	ExitStatus bool
 	UI         bool
+
+	AnchoredDiff bool
 }
 
 func (s *DiffFlags) SetWithPrefix(prefix string, cmd *cobra.Command) {
@@ -39,4 +41,6 @@ func (s *DiffFlags) SetWithPrefix(prefix string, cmd *cobra.Command) {
 
 	cmd.Flags().StringVar(&s.Filter, prefix+"filter", "", `Set changes filter (example: {"and":[{"ops":["update"]},{"existingResource":{"kinds":["Deployment"]}]})`)
 	cmd.Flags().BoolVar(&s.ChangesYAML, prefix+"changes-yaml", false, "Print YAML to be applied")
+
+	cmd.Flags().BoolVar(&s.AnchoredDiff, prefix+"anchored", false, "Allow using anchored diff for large resources")
 }
diff --git a/pkg/kapp/config/default_test.go b/pkg/kapp/config/default_test.go
@@ -15,7 +15,7 @@ import (
 func TestDefaultTemplateRules(t *testing.T) {
 	_, defaultConfig, err := config.NewConfFromResourcesWithDefaults([]ctlres.Resource{})
 	require.NoError(t, err)
-	changeFactory := ctldiff.NewChangeFactory(defaultConfig.RebaseMods(), defaultConfig.DiffAgainstLastAppliedFieldExclusionMods(), defaultConfig.DiffAgainstExistingFieldExclusionMods())
+	changeFactory := ctldiff.NewChangeFactory(defaultConfig.RebaseMods(), defaultConfig.DiffAgainstLastAppliedFieldExclusionMods(), defaultConfig.DiffAgainstExistingFieldExclusionMods(), ctldiff.ChangeOpts{false})
 
 	testCases := []struct {
 		description  string

diff --git a/pkg/kapp/diff/change.go b/pkg/kapp/diff/change.go
@@ -6,7 +6,6 @@ package diff
 import (
 	"github.com/cppforlife/go-patch/patch"
 	ctlres "github.com/vmware-tanzu/carvel-kapp/pkg/kapp/resources"
-	"gopkg.in/yaml.v2"
 )
 
 type ChangeOp string
@@ -46,11 +45,13 @@ type ChangeImpl struct {
 	configurableTextDiff *ConfigurableTextDiff
 	opsDiff              *OpsDiff
 	changeOpVal          ChangeOp
+
+	opts ChangeOpts
 }
 
 var _ Change = &ChangeImpl{}
 
-func NewChange(existingRes, newRes, appliedRes, clusterOriginalRes ctlres.Resource) *ChangeImpl {
+func NewChange(existingRes, newRes, appliedRes, clusterOriginalRes ctlres.Resource, opts ChangeOpts) *ChangeImpl {
 	if existingRes == nil && newRes == nil {
 		panic("Expected either existingRes or newRes be non-nil")
 	}
@@ -68,7 +69,7 @@ func NewChange(existingRes, newRes, appliedRes, clusterOriginalRes ctlres.Resour
 		clusterOriginalRes = clusterOriginalRes.DeepCopy()
 	}
 
-	return &ChangeImpl{existingRes: existingRes, newRes: newRes, appliedRes: appliedRes, clusterOriginalRes: clusterOriginalRes}
+	return &ChangeImpl{existingRes: existingRes, newRes: newRes, appliedRes: appliedRes, clusterOriginalRes: clusterOriginalRes, opts: opts}
 }
 
 func (d *ChangeImpl) NewOrExistingResource() ctlres.Resource {
@@ -130,7 +131,7 @@ func (d *ChangeImpl) isIgnoredTransient() bool {
 func (d *ChangeImpl) ConfigurableTextDiff() *ConfigurableTextDiff {
 	// diff is called very often, so memoize
 	if d.configurableTextDiff == nil {
-		d.configurableTextDiff = NewConfigurableTextDiff(d.existingRes, d.newRes, d.IsIgnored())
+		d.configurableTextDiff = NewConfigurableTextDiff(d.existingRes, d.newRes, d.IsIgnored(), d.opts)
 	}
 	return d.configurableTextDiff
 }
@@ -147,36 +148,7 @@ func (d *ChangeImpl) OpsDiff() OpsDiff {
 }
 
 func (d *ChangeImpl) calculateOpsDiff() OpsDiff {
-	var existingObj interface{}
-	var newObj interface{}
-
-	if d.existingRes != nil {
-		existingBytes, err := d.existingRes.AsYAMLBytes()
-		if err != nil {
-			panic("yamling existingRes") // TODO panic
-		}
-
-		err = yaml.Unmarshal(existingBytes, &existingObj)
-		if err != nil {
-			panic("unyamling existingRes") // TODO panic
-		}
-	}
-
-	if d.newRes != nil {
-		newBytes, err := d.newRes.AsYAMLBytes()
-		if err != nil {
-			panic("yamling newRes") // TODO panic
-		}
-
-		err = yaml.Unmarshal(newBytes, &newObj)
-		if err != nil {
-			panic("unyamling newRes") // TODO panic
-		}
-	} else if d.IsIgnored() {
-		newObj = existingObj // show as no changes
-	}
-
-	return OpsDiff(patch.Diff{Left: existingObj, Right: newObj}.Calculate())
+	return OpsDiff(patch.Diff{Left: d.existingRes.UnstructuredObject(), Right: d.newRes.UnstructuredObject()}.Calculate())
 }
 
 func (d *ChangeImpl) newResHasExistsAnnotation() bool {

diff --git a/pkg/kapp/diff/change_factory.go b/pkg/kapp/diff/change_factory.go
@@ -11,12 +11,17 @@ type ChangeFactory struct {
 	rebaseMods                               []ctlres.ResourceModWithMultiple
 	diffAgainstLastAppliedFieldExclusionMods []ctlres.FieldRemoveMod
 	diffAgainstExistingFieldExclusionRules   []ctlres.FieldRemoveMod
+	opts                                     ChangeOpts
+}
+
+type ChangeOpts struct {
+	AllowAnchoredDiff bool
 }
 
 func NewChangeFactory(rebaseMods []ctlres.ResourceModWithMultiple,
-	diffAgainstLastAppliedFieldExclusionMods []ctlres.FieldRemoveMod, diffAgainstExistingFieldExclusionRules []ctlres.FieldRemoveMod) ChangeFactory {
+	diffAgainstLastAppliedFieldExclusionMods []ctlres.FieldRemoveMod, diffAgainstExistingFieldExclusionRules []ctlres.FieldRemoveMod, opts ChangeOpts) ChangeFactory {
 
-	return ChangeFactory{rebaseMods, diffAgainstLastAppliedFieldExclusionMods, diffAgainstExistingFieldExclusionRules}
+	return ChangeFactory{rebaseMods, diffAgainstLastAppliedFieldExclusionMods, diffAgainstExistingFieldExclusionRules, opts}
 }
 
 func (f ChangeFactory) NewChangeAgainstLastApplied(existingRes, newRes ctlres.Resource) (Change, error) {
@@ -59,7 +64,7 @@ func (f ChangeFactory) NewChangeAgainstLastApplied(existingRes, newRes ctlres.Re
 		return nil, err
 	}
 
-	return NewChange(existingRes, rebasedNewRes, newRes, existingResForRebasing), nil
+	return NewChange(existingRes, rebasedNewRes, newRes, existingResForRebasing, f.opts), nil
 }
 
 func (f ChangeFactory) NewExactChange(existingRes, newRes ctlres.Resource) (Change, error) {
@@ -86,7 +91,7 @@ func (f ChangeFactory) NewExactChange(existingRes, newRes ctlres.Resource) (Chan
 		return nil, err
 	}
 
-	return NewChange(existingRes, rebasedNewRes, newRes, existingRes), nil
+	return NewChange(existingRes, rebasedNewRes, newRes, existingRes, f.opts), nil
 }
 
 func (f ChangeFactory) NewResourceWithHistory(resource ctlres.Resource) ResourceWithHistory {

diff --git a/pkg/kapp/diff/change_set_test.go b/pkg/kapp/diff/change_set_test.go
@@ -48,7 +48,7 @@ metadata:
 		},
 	}
 
-	changeFactory := ctldiff.NewChangeFactory(mods, nil, nil)
+	changeFactory := ctldiff.NewChangeFactory(mods, nil, nil, ctldiff.ChangeOpts{false})
 	changeSet := ctldiff.NewChangeSet([]ctlres.Resource{existingRes}, []ctlres.Resource{newRes},
 		ctldiff.ChangeSetOpts{}, changeFactory)
 
@@ -106,7 +106,7 @@ metadata:
 		},
 	}
 
-	changeFactory := ctldiff.NewChangeFactory(mods, nil, nil)
+	changeFactory := ctldiff.NewChangeFactory(mods, nil, nil, ctldiff.ChangeOpts{false})
 	changeSet := ctldiff.NewChangeSet([]ctlres.Resource{existingRes}, []ctlres.Resource{newRes},
 		ctldiff.ChangeSetOpts{}, changeFactory)
 
@@ -174,7 +174,7 @@ metadata:
 		},
 	}
 
-	changeFactory := ctldiff.NewChangeFactory(rebaseMods, ignoreFieldsMods, nil)
+	changeFactory := ctldiff.NewChangeFactory(rebaseMods, ignoreFieldsMods, nil, ctldiff.ChangeOpts{false})
 	changeSet := ctldiff.NewChangeSet([]ctlres.Resource{existingRes}, []ctlres.Resource{newRes},
 		ctldiff.ChangeSetOpts{AgainstLastApplied: true}, changeFactory)
 
@@ -246,7 +246,7 @@ metadata:
 		},
 	}
 
-	changeFactory := ctldiff.NewChangeFactory(rebaseMods, ignoreFieldsMods, nil)
+	changeFactory := ctldiff.NewChangeFactory(rebaseMods, ignoreFieldsMods, nil, ctldiff.ChangeOpts{false})
 	changeSet := ctldiff.NewChangeSet([]ctlres.Resource{existingRes}, []ctlres.Resource{newRes},
 		ctldiff.ChangeSetOpts{AgainstLastApplied: true}, changeFactory)
 
@@ -304,7 +304,7 @@ metadata:
 		},
 	}
 
-	changeFactory := ctldiff.NewChangeFactory(mods, nil, nil)
+	changeFactory := ctldiff.NewChangeFactory(mods, nil, nil, ctldiff.ChangeOpts{false})
 	changeSet := ctldiff.NewChangeSet([]ctlres.Resource{existingRes}, []ctlres.Resource{newRes},
 		ctldiff.ChangeSetOpts{}, changeFactory)
 

diff --git a/pkg/kapp/diff/change_set_with_versioned_rs.go b/pkg/kapp/diff/change_set_with_versioned_rs.go
@@ -198,7 +198,7 @@ func (d ChangeSetWithVersionedRs) noopAndDeleteChanges(
 }
 
 func (d ChangeSetWithVersionedRs) newKeepChange(existingRes ctlres.Resource) Change {
-	return NewChangePrecalculated(existingRes, nil, nil, ChangeOpKeep, NewConfigurableTextDiff(existingRes, nil, true), OpsDiff{})
+	return NewChangePrecalculated(existingRes, nil, nil, ChangeOpKeep, NewConfigurableTextDiff(existingRes, nil, true, ChangeOpts{false}), OpsDiff{})
 }
 
 func (d ChangeSetWithVersionedRs) newNoopChange(existingRes ctlres.Resource) Change {

diff --git a/pkg/kapp/diff/configurable_text_diff.go b/pkg/kapp/diff/configurable_text_diff.go
@@ -16,10 +16,12 @@ type ConfigurableTextDiff struct {
 	ignored             bool
 
 	memoizedTextDiff *TextDiff
+
+	opts ChangeOpts
 }
 
-func NewConfigurableTextDiff(existingRes, newRes ctlres.Resource, ignored bool) *ConfigurableTextDiff {
-	return &ConfigurableTextDiff{existingRes, newRes, ignored, nil}
+func NewConfigurableTextDiff(existingRes, newRes ctlres.Resource, ignored bool, opts ChangeOpts) *ConfigurableTextDiff {
+	return &ConfigurableTextDiff{existingRes, newRes, ignored, nil, opts}
 }
 
 func (d ConfigurableTextDiff) Full() TextDiff {
@@ -73,5 +75,5 @@ func (d ConfigurableTextDiff) calculate(existingRes, newRes ctlres.Resource) Tex
 		newLines = existingLines // show as no changes
 	}
 
-	return NewTextDiff(existingLines, newLines)
+	return NewTextDiff(existingLines, newLines, d.opts.AllowAnchoredDiff)
 }
diff --git a/pkg/kapp/diff/masked_resource.go b/pkg/kapp/diff/masked_resource.go
@@ -21,7 +21,7 @@ func NewMaskedResource(res ctlres.Resource, rules []ctlconf.DiffMaskRule) Masked
 	if res == nil {
 		panic("Expected res be non-nil")
 	}
-	return MaskedResource{res.DeepCopy(), rules}
+	return MaskedResource{res, rules}
 }
 
 func (r MaskedResource) Resource() (ctlres.Resource, error) {

diff --git a/pkg/kapp/diff/rebased_resource.go b/pkg/kapp/diff/rebased_resource.go
@@ -19,13 +19,6 @@ func NewRebasedResource(existingRes, newRes ctlres.Resource, mods []ctlres.Resou
 		panic("Expected either existingRes or newRes be non-nil")
 	}
 
-	if existingRes != nil {
-		existingRes = existingRes.DeepCopy()
-	}
-	if newRes != nil {
-		newRes = newRes.DeepCopy()
-	}
-
 	return RebasedResource{existingRes: existingRes, newRes: newRes, mods: mods}
 }
 
@@ -45,10 +38,10 @@ func (r RebasedResource) Resource() (ctlres.Resource, error) {
 		if t.IsResourceMatching(result) {
 			// copy newRes and existingRes as they may be modified in place
 			resSources := map[ctlres.FieldCopyModSource]ctlres.Resource{
-				ctlres.FieldCopyModSourceNew:      r.newRes.DeepCopy(),
-				ctlres.FieldCopyModSourceExisting: r.existingRes.DeepCopy(),
+				ctlres.FieldCopyModSourceNew:      r.newRes,
+				ctlres.FieldCopyModSourceExisting: r.existingRes,
 				// Might be useful for more advanced rebase rules like ytt-based
-				ctlres.FieldCopyModSource("_current"): result.DeepCopy(),
+				ctlres.FieldCopyModSource("_current"): result,
 			}
 
 			err := t.ApplyFromMultiple(result, resSources)

diff --git a/pkg/kapp/diff/resource_with_removed_fields.go b/pkg/kapp/diff/resource_with_removed_fields.go
@@ -13,9 +13,6 @@ type ResourceWithRemovedFields struct {
 }
 
 func NewResourceWithRemovedFields(res ctlres.Resource, mods []ctlres.FieldRemoveMod) ResourceWithRemovedFields {
-	if res != nil {
-		res = res.DeepCopy()
-	}
 	return ResourceWithRemovedFields{res: res, mods: mods}
 }
 

diff --git a/pkg/kapp/diff/text_diff.go b/pkg/kapp/diff/text_diff.go
@@ -15,7 +15,11 @@ type TextDiff struct {
 	recs []difflib.DiffRecord
 }
 
-func NewTextDiff(existingLines, newLines []string) TextDiff {
+func NewTextDiff(existingLines, newLines []string, allowAnchoredDiff bool) TextDiff {
+	if allowAnchoredDiff && (len(existingLines) > 500 || len(newLines) > 500) {
+		// Diff is memory hungry, use AnchoredDiff for large resources
+		return TextDiff{difflib.AnchoredDiff(existingLines, newLines)}
+	}
 	return TextDiff{difflib.Diff(existingLines, newLines)}
 }
 

diff --git a/pkg/kapp/resources/mod_field_copy.go b/pkg/kapp/resources/mod_field_copy.go
@@ -39,6 +39,7 @@ func (t FieldCopyMod) ApplyFromMultiple(res Resource, srcs map[FieldCopyModSourc
 		// Make a copy of resource, to avoid modifications
 		// that may be done even in case when there is nothing to copy
 		updatedRes := res.DeepCopy()
+		source = source.DeepCopy()
 		updated, err := t.apply(updatedRes.unstructured().Object, source.unstructured().Object, t.Path, Path{}, srcs)
 		if err != nil {
 			return fmt.Errorf("FieldCopyMod for path '%s' on resource '%s': %s", t.Path.AsString(), res.Description(), err)
@@ -198,7 +199,7 @@ func (t FieldCopyMod) copyIntoMap(obj map[string]interface{}, fullPath Path, src
 			continue
 		}
 
-		val, found, err := t.obtainValue(srcRes.unstructured().Object, fullPath)
+		val, found, err := t.obtainValue(srcRes.DeepCopy().unstructured().Object, fullPath)
 		if err != nil {
 			return false, err
 		} else if !found {

diff --git a/pkg/kapp/resources/resource.go b/pkg/kapp/resources/resource.go
@@ -61,6 +61,8 @@ type Resource interface {
 	MarkTransient(bool)
 	Transient() bool
 
+	UnstructuredObject() map[string]interface{}
+
 	unstructured() unstructured.Unstructured     // private
 	unstructuredPtr() *unstructured.Unstructured // private
 	setUnstructured(unstructured.Unstructured)   // private
@@ -280,6 +282,8 @@ func (r *ResourceImpl) Debug(title string) {
 func (r *ResourceImpl) SetOrigin(origin string) { r.origin = origin }
 func (r *ResourceImpl) Origin() string          { return r.origin }
 
+func (r *ResourceImpl) UnstructuredObject() map[string]interface{} { return r.un.Object }
+
 func (r *ResourceImpl) unstructured() unstructured.Unstructured      { return r.un }
 func (r *ResourceImpl) unstructuredPtr() *unstructured.Unstructured  { return &r.un }
 func (r *ResourceImpl) setUnstructured(un unstructured.Unstructured) { r.un = un }
diff --git a/pkg/kapp/resources/resource_with_managed_fields.go b/pkg/kapp/resources/resource_with_managed_fields.go
@@ -9,9 +9,6 @@ type ResourceWithManagedFields struct {
 }
 
 func NewResourceWithManagedFields(res Resource, managedFields bool) ResourceWithManagedFields {
-	if res != nil {
-		res = res.DeepCopy()
-	}
 	return ResourceWithManagedFields{res: res, managedFields: managedFields}
 }