Add namespace for config map and secret generators

pkg/commands/build/testdata/testcase-generators-namespace/expected.yaml

@@ -0,0 +1,33 @@
+apiVersion: v1
+data:
+  altGreeting: Good Morning from default namespace!
+  enableRisky: "false"
+kind: ConfigMap
+metadata:
+  name: the-map-4959m5tm6c
+---
+apiVersion: v1
+data:
+  altGreeting: Good Morning from non-default namespace!
+  enableRisky: "false"
+kind: ConfigMap
+metadata:
+  name: the-non-default-namespace-map-b6h49k7mt8
+  namespace: non-default
+---
+apiVersion: v1
+data:
+  password.txt: dmVyeSRlY3JldA==
+kind: Secret
+metadata:
+  name: the-secret-cfbmct72tb
+type: Opaque
+---
+apiVersion: v1
+data:
+  password.txt: dmVyeSRlY3JldA==
+kind: Secret
+metadata:
+  name: the-non-default-namespace-secret-255294gd9d
+  namespace: non-default
+type: Opaque

pkg/commands/build/testdata/testcase-generators-namespace/in/kustomization.yaml

@@ -0,0 +1,19 @@
+configMapGenerator:
+- name: the-non-default-namespace-map
+  namespace: non-default
+  literals:
+  - altGreeting=Good Morning from non-default namespace!
+  - enableRisky="false"
+- name: the-map
+  literals:
+  - altGreeting=Good Morning from default namespace!
+  - enableRisky="false"
+
+secretGenerator:
+- name: the-non-default-namespace-secret
+  namespace: non-default
+  commands:
+    password.txt: "cat password.txt"
+- name: the-secret
+  commands:
+    password.txt: "cat password.txt"

pkg/commands/build/testdata/testcase-generators-namespace/in/password.txt

@@ -0,0 +1 @@
+very$ecret

pkg/commands/build/testdata/testcase-generators-namespace/test.yaml

@@ -0,0 +1,4 @@
+description: generators-namespace
+args: []
+filename: testdata/testcase-generators-namespace/in
+expectedStdout: testdata/testcase-generators-namespace/expected.yaml

pkg/types/kustomization.go

@@ -153,6 +153,9 @@ type ConfigMapArgs struct {
 	// hash(content of configmap).
 	Name string `json:"name,omitempty" yaml:"name,omitempty"`
 
+	// Namespace for the configmap, optional
+	Namespace string `json:"namespace,omitempty" yaml:"namespace,omitempty"`
+
 	// behavior of configmap, must be one of create, merge and replace
 	// 'create': create a new one;
 	// 'replace': replace the existing one;
@@ -170,6 +173,9 @@ type SecretArgs struct {
 	// hash(content of secret).
 	Name string `json:"name,omitempty" yaml:"name,omitempty"`
 
+	// Namespace for the secret, optional
+	Namespace string `json:"namespace,omitempty" yaml:"namespace,omitempty"`
+
 	// behavior of secretGenerator, must be one of create, merge and replace
 	// 'create': create a new one;
 	// 'replace': replace the existing one;