Implement function target selectors, set infrastructure and handle pruning (#2447)

* Implement function selectors with basicpipeline test

* Copy generator test

* generator test: only select generated resource

* Unit tests for merging resources

* fix lint errors

* Unit tests for isMatch method

* Validator test

* Select by PackagePath

* Add comment to annotation, optimize presentIn calls

* Address suggested changes

* Imperative filtering

* Out of place fn chain test

* Update flag descriptions

* Optimize calls

* Suggested changes

Author: phanimarupaka

e2e/testdata/fn-eval/selectors/basicpipeline/.expected/diff.patch

@@ -0,0 +1,12 @@
+diff --git a/resources.yaml b/resources.yaml
+index 7a494c9..9d82bd6 100644
+--- a/resources.yaml
++++ b/resources.yaml
+@@ -15,6 +15,7 @@ apiVersion: apps/v1
+ kind: Deployment
+ metadata:
+   name: nginx-deployment
++  namespace: staging
+ spec:
+   replicas: 3
+ ---

e2e/testdata/fn-eval/selectors/basicpipeline/.expected/exec.sh

@@ -0,0 +1,18 @@
+#! /bin/bash
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -eo pipefail
+
+kpt fn eval -i set-namespace:v0.1.3 --name nginx-deployment --kind Deployment -- namespace=staging

e2e/testdata/fn-eval/selectors/basicpipeline/.krmignore

@@ -0,0 +1 @@
+.expected

e2e/testdata/fn-eval/selectors/basicpipeline/resources.yaml

@@ -0,0 +1,26 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nginx-deployment
+spec:
+  replicas: 3
+---
+apiVersion: custom.io/v1
+kind: Custom
+metadata:
+  name: custom
+spec:
+  image: nginx:1.2.3

e2e/testdata/fn-eval/selectors/out-of-place-fnchain-unwrap/.expected/config.yaml

@@ -0,0 +1,49 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+stdErr: |
+  [RUNNING] "gcr.io/kpt-fn/set-namespace:v0.1.3"
+  [PASS] "gcr.io/kpt-fn/set-namespace:v0.1.3" in 0s
+  [RUNNING] "gcr.io/kpt-fn/set-annotations:v0.1.3"
+  [PASS] "gcr.io/kpt-fn/set-annotations:v0.1.3" in 0s
+  [RUNNING] "gcr.io/kpt-fn/set-labels:v0.1.3"
+  [PASS] "gcr.io/kpt-fn/set-labels:v0.1.3" in 0s
+stdOut: |
+  apiVersion: apps/v1
+  kind: Deployment
+  metadata:
+    name: nginx-deployment
+    namespace: staging
+    labels:
+      tier: backend
+  spec:
+    replicas: 3
+    selector:
+      matchLabels:
+        tier: backend
+    template:
+      metadata:
+        labels:
+          tier: backend
+  ---
+  apiVersion: custom.io/v1
+  kind: Custom
+  metadata:
+    name: custom
+    annotations:
+      foo: bar
+    labels:
+      tier: backend
+  spec:
+    image: nginx:1.2.3

e2e/testdata/fn-eval/selectors/out-of-place-fnchain-unwrap/.expected/exec.sh

@@ -0,0 +1,22 @@
+#! /bin/bash
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+set -eo pipefail
+
+kpt fn source \
+| kpt fn eval - --image gcr.io/kpt-fn/set-namespace:v0.1.3 --kind Deployment -o stdout -- namespace=staging \
+| kpt fn eval - --image gcr.io/kpt-fn/set-annotations:v0.1.3 --name custom -- foo=bar \
+| kpt fn eval - --image gcr.io/kpt-fn/set-labels:v0.1.3 -o unwrap -- tier=backend

e2e/testdata/fn-eval/selectors/out-of-place-fnchain-unwrap/.krmignore

@@ -0,0 +1 @@
+.expected

e2e/testdata/fn-eval/selectors/out-of-place-fnchain-unwrap/resources.yaml

@@ -0,0 +1,13 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: nginx-deployment
+spec:
+  replicas: 3
+---
+apiVersion: custom.io/v1
+kind: Custom
+metadata:
+  name: custom
+spec:
+  image: nginx:1.2.3

e2e/testdata/fn-render/selectors/basicpipeline/.expected/diff.patch

@@ -0,0 +1,29 @@
+diff --git a/resources.yaml b/resources.yaml
+index 7a494c9..1d36135 100644
+--- a/resources.yaml
++++ b/resources.yaml
+@@ -15,12 +15,24 @@ apiVersion: apps/v1
+ kind: Deployment
+ metadata:
+   name: nginx-deployment
++  namespace: staging
++  labels:
++    tier: backend
+ spec:
+   replicas: 3
++  selector:
++    matchLabels:
++      tier: backend
++  template:
++    metadata:
++      labels:
++        tier: backend
+ ---
+ apiVersion: custom.io/v1
+ kind: Custom
+ metadata:
+   name: custom
++  labels:
++    tier: backend
+ spec:
+   image: nginx:1.2.3

e2e/testdata/fn-render/selectors/basicpipeline/.krmignore

@@ -0,0 +1 @@
+.expected