change: components apply after all generators and transformers applied (#5170)

* change: components apply after all generator and transformer applied

* fix name for a test case

* add comment about when the components will be executed

* components are applied before transformer

api/internal/target/kusttarget.go

@@ -202,10 +202,6 @@ func (kt *KustTarget) accumulateTarget(ra *accumulator.ResAccumulator) (
 	if err != nil {
 		return nil, errors.WrapPrefixf(err, "accumulating resources")
 	}
-	ra, err = kt.accumulateComponents(ra, kt.kustomization.Components)
-	if err != nil {
-		return nil, errors.WrapPrefixf(err, "accumulating components")
-	}
 	tConfig, err := builtinconfig.MakeTransformerConfig(
 		kt.ldr, kt.kustomization.Configurations)
 	if err != nil {
@@ -230,6 +226,14 @@ func (kt *KustTarget) accumulateTarget(ra *accumulator.ResAccumulator) (
 	if err != nil {
 		return nil, err
 	}
+
+	// components are expected to execute after reading resources and adding generators ,before applying transformers and validation.
+	// https://github.com/kubernetes-sigs/kustomize/pull/5170#discussion_r1212101287
+	ra, err = kt.accumulateComponents(ra, kt.kustomization.Components)
+	if err != nil {
+		return nil, errors.WrapPrefixf(err, "accumulating components")
+	}
+
 	err = kt.runTransformers(ra)
 	if err != nil {
 		return nil, err

api/krusty/component_test.go

@@ -39,7 +39,7 @@ resources:
 - deploy.yaml
 configMapGenerator:
 - name: my-configmap
-  literals:	
+  literals:
   - testValue=purple
   - otherValue=green
 `)
@@ -64,7 +64,7 @@ resources:
 configMapGenerator:
 - name: my-configmap
   behavior: merge
-  literals:	
+  literals:
   - testValue=blue
   - compValue=red
 `)
@@ -154,7 +154,7 @@ spec:
 configMapGenerator:
 - name: my-configmap
   behavior: merge
-  literals:	
+  literals:
   - otherValue=orange
 `),
 				writeK("prod", `
@@ -319,7 +319,7 @@ resources:
 configMapGenerator:
 - name: my-configmap
   behavior: merge
-  literals:	
+  literals:
   - compValue=red
   - testValue=blue
 `),
@@ -350,7 +350,7 @@ kind: Component
 configMapGenerator:
 - name: my-configmap
   behavior: merge
-  literals:	
+  literals:
   - otherValue=orange
 `),
 			},
@@ -562,7 +562,7 @@ kind: Component
 configMapGenerator:
 - name: my-configmap
   behavior: merge
-  literals:	
+  literals:
   - otherValue=orange
 `),
 			},
@@ -657,3 +657,113 @@ components:
 		})
 	}
 }
+
+func TestOrderOfAccumulatedComponent(t *testing.T) {
+	tests := map[string]struct {
+		input          []FileGen
+		expectedOutput string
+	}{
+		"components_using_a_generated_resource_by_configMapGenerator": {
+			input: []FileGen{
+				writeK("", `
+resources:
+- resource.yaml
+components:
+- components
+configMapGenerator:
+- name: generated-resource
+  literals:
+  - key=value
+  options:
+    disableNameSuffixHash: true`),
+				writeF("resource.yaml", `
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: config-from-resources
+data:
+  foo: bar`),
+				writeC("/components", `
+apiVersion: kustomize.config.k8s.io/v1alpha1
+kind: Component
+nameSuffix: -suffix
+`),
+			},
+			expectedOutput: `
+apiVersion: v1
+data:
+  foo: bar
+kind: ConfigMap
+metadata:
+  name: config-from-resources-suffix
+---
+apiVersion: v1
+data:
+  key: value
+kind: ConfigMap
+metadata:
+  name: generated-resource-suffix
+`},
+		"components_are_applied_before_replacements_transformer_applied": {
+			input: []FileGen{
+				writeK("", `
+resources:
+- resource.yaml
+components:
+- components
+replacements:
+- source:
+    kind: Pod
+    name: myapp-pod
+    fieldPath: metadata.namespace
+  targets:
+  - select:
+      kind: Pod
+      name: myapp-pod
+    fieldPaths:
+    - spec.containers.[name=myapp-container].env.[name=CURRENT_POD_NAMESPACE].value`),
+				writeF("resource.yaml", `
+apiVersion: v1
+kind: Pod
+metadata:
+  name: myapp-pod
+  namespace: dev-assa
+spec:
+  containers:
+  - image: busybox
+    name: myapp-container
+    env:
+    - name: CURRENT_POD_NAMESPACE
+      value: "$(PLACEHOLDER)"`),
+				writeC("/components", `
+apiVersion: kustomize.config.k8s.io/v1alpha1
+kind: Component
+namespace: kustomize-namespace`),
+			},
+			expectedOutput: `
+apiVersion: v1
+kind: Pod
+metadata:
+  name: myapp-pod
+  namespace: kustomize-namespace
+spec:
+  containers:
+  - env:
+    - name: CURRENT_POD_NAMESPACE
+      value: kustomize-namespace
+    image: busybox
+    name: myapp-container
+`},
+	}
+
+	for testName, test := range tests {
+		t.Run(testName, func(t *testing.T) {
+			th := kusttest_test.MakeHarness(t)
+			for _, f := range test.input {
+				f(th)
+			}
+			m := th.Run(".", th.MakeDefaultOptions())
+			th.AssertActualEqualsExpected(m, test.expectedOutput)
+		})
+	}
+}