feat(replacements): add IgnoreMissingField option

api/filters/replacement/replacement.go

@@ -185,20 +185,24 @@ func containsRejectId(rejects []*types.Selector, ids []resid.ResId) bool {
 func copyValueToTarget(target *yaml.RNode, value *yaml.RNode, selector *types.TargetSelector) error {
 	for _, fp := range selector.FieldPaths {
 		createKind := yaml.Kind(0) // do not create
+		ignoreMissingField := false
+		if selector.Options != nil {
+			ignoreMissingField = selector.Options.IgnoreMissingField
+		}
 		if selector.Options != nil && selector.Options.Create {
 			createKind = value.YNode().Kind
 		}
 		targetFieldList, err := target.Pipe(&yaml.PathMatcher{
 			Path:   kyaml_utils.SmarterPathSplitter(fp, "."),
 			Create: createKind})
-		if err != nil {
+		if err != nil && !ignoreMissingField {
 			return errors.WrapPrefixf(err, fieldRetrievalError(fp, createKind != 0)) //nolint:govet
 		}
 		targetFields, err := targetFieldList.Elements()
-		if err != nil {
+		if err != nil && !ignoreMissingField {
 			return errors.WrapPrefixf(err, fieldRetrievalError(fp, createKind != 0)) //nolint:govet
 		}
-		if len(targetFields) == 0 {
+		if len(targetFields) == 0 && !ignoreMissingField {
 			return errors.Errorf(fieldRetrievalError(fp, createKind != 0)) //nolint:govet
 		}
 

api/filters/replacement/replacement_test.go

@@ -2830,6 +2830,145 @@ spec:
 `,
 			expectedErr: "unable to find or create field \"spec.tls.5.hosts.5\" in replacement target: index 5 specified but only 0 elements found",
 		},
+		"replace target path and ignore missing fields": {
+			input: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: clusterConfig
+data:
+  accountId: "123456789101"
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-with-field
+  annotations:
+    eks.amazonaws.com/role-arn: arn:aws:iam::REPLACEME:role/super-admin
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-without-field
+`,
+			replacements: `replacements:
+- source:
+    kind: ConfigMap
+    name: clusterConfig
+    fieldPath: data.accountId
+  targets:
+    - select:
+        kind: ServiceAccount
+      fieldPaths:
+        - metadata.annotations.[eks.amazonaws.com/role-arn]
+      options:
+        # not all Service Accounts have irsa annotations
+        ignoreMissingField: true
+        delimiter: ":"
+        index: 4
+`,
+			expected: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: clusterConfig
+data:
+  accountId: "123456789101"
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-with-field
+  annotations:
+    eks.amazonaws.com/role-arn: arn:aws:iam::123456789101:role/super-admin
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-without-field`,
+		},
+		"no replacement or error with ignore missing fields when there is no matching field": {
+			input: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: clusterConfig
+data:
+  accountId: "123456789101"
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-without-field
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-without-field-again
+`,
+			replacements: `replacements:
+- source:
+    kind: ConfigMap
+    name: clusterConfig
+    fieldPath: data.accountId
+  targets:
+    - select:
+        kind: ServiceAccount
+      fieldPaths:
+        - metadata.annotations.[eks.amazonaws.com/role-arn]
+      options:
+        # not all Service Accounts have irsa annotations
+        ignoreMissingField: true
+        delimiter: ":"
+        index: 4
+`,
+			expected: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: clusterConfig
+data:
+  accountId: "123456789101"
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-without-field
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-without-field-again`,
+		},
+		"non matching field with no options": {
+			input: `apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: clusterConfig
+data:
+  accountId: "123456789101"
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-with-field
+  annotations:
+    eks.amazonaws.com/role-arn: arn:aws:iam::REPLACEME:role/super-admin
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: service-account-without-field-again
+`,
+			replacements: `replacements:
+- source:
+    kind: ConfigMap
+    name: clusterConfig
+    fieldPath: data.accountId
+  targets:
+    - select:
+        kind: ServiceAccount
+      fieldPaths:
+        - metadata.annotations.[eks.amazonaws.com/role-arn]
+`,
+			expectedErr: `unable to find field "metadata.annotations.[eks.amazonaws.com/role-arn]" in replacement target`,
+		},
 	}
 
 	for tn, tc := range testCases {

api/types/replacement.go

@@ -77,11 +77,14 @@ type FieldOptions struct {
 
 	// If field missing, add it.
 	Create bool `json:"create,omitempty" yaml:"create,omitempty"`
+
+	// If field missing, ignore it.
+	IgnoreMissingField bool `json:"ignoreMissingField,omitempty" yaml:"ignoreMissingField,omitempty"`
 }
 
 func (fo *FieldOptions) String() string {
-	if fo == nil || (fo.Delimiter == "" && !fo.Create) {
+	if fo == nil || (fo.Delimiter == "" && !fo.Create && !fo.IgnoreMissingField) {
 		return ""
 	}
-	return fmt.Sprintf("%s(%d), create=%t", fo.Delimiter, fo.Index, fo.Create)
+	return fmt.Sprintf("%s(%d), create=%t, ignoreMissingField=%t", fo.Delimiter, fo.Index, fo.Create, fo.IgnoreMissingField)
 }

site/content/en/docs/Reference/API/Kustomization File/replacements.md

@@ -63,6 +63,7 @@ replacements:
       delimiter: string
       index: int
       create: bool
+      ignoreMissingField: bool
   targets:
   - select:
       group: string
@@ -103,6 +104,7 @@ replacements:
 |`delimiter`|  | Used to split/join the field
 |`index`| | Which position in the split to consider | `0`
 |`create`|  | If target field is missing, add it | `false`
+|`ignoreMissingField`|  | If target field is missing, ignore it | `false`
 
 #### Source
 The source field is a selector that determines the source of the value by finding a