Out of place hydration using render and eval (#2137)

* Implement out of place hydration for eval and render

* e2e tests for oop hydration

* Reference docs

* Fix tests

* Address suggested changes

* Unit tests for WriteFnOutput

* out of place support in test harness

* added support for fn-eval

* output of place tests

* --results-dir option should not print progress to stdout

* print results dir message for error

* Update reference docs with default behavior

Co-authored-by: droot <sunilarora@google.com>

e2e/testdata/fn-eval/out-of-place-dir/.expected/diff.patch

@@ -0,0 +1,34 @@
+diff --git a/out/resources.yaml b/out/resources.yaml
+new file mode 100644
+index 0000000..254b9cd
+--- /dev/null
++++ b/out/resources.yaml
+@@ -0,0 +1,28 @@
++# 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
++  namespace: staging
++spec:
++  replicas: 3
++---
++apiVersion: custom.io/v1
++kind: Custom
++metadata:
++  name: custom
++  namespace: staging
++spec:
++  image: nginx:1.2.3

e2e/testdata/fn-eval/out-of-place-dir/.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 --image gcr.io/kpt-fn/set-namespace:v0.1.3 -o out -- namespace=staging

e2e/testdata/fn-eval/out-of-place-dir/.krmignore

@@ -0,0 +1,2 @@
+.expected
+out

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

@@ -0,0 +1,52 @@
+stdOut: |
+  apiVersion: config.kubernetes.io/v1alpha1
+  kind: ResourceList
+  items:
+    # 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
+        namespace: staging
+        labels:
+          tier: backend
+        annotations:
+          config.kubernetes.io/index: "0"
+          config.kubernetes.io/path: resources.yaml
+          foo: bar
+      spec:
+        replicas: 3
+        selector:
+          matchLabels:
+            tier: backend
+        template:
+          metadata:
+            labels:
+              tier: backend
+            annotations:
+              foo: bar
+    - apiVersion: custom.io/v1
+      kind: Custom
+      metadata:
+        name: custom
+        namespace: staging
+        labels:
+          tier: backend
+        annotations:
+          config.kubernetes.io/index: "1"
+          config.kubernetes.io/path: resources.yaml
+          foo: bar
+      spec:
+        image: nginx:1.2.3

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

@@ -0,0 +1,7 @@
+#! /bin/bash
+
+set -eo pipefail
+
+kpt fn eval --image gcr.io/kpt-fn/set-namespace:v0.1.3 -o stdout -- namespace=staging \
+| kpt fn eval - --image gcr.io/kpt-fn/set-annotations:v0.1.3 -- foo=bar \
+| kpt fn eval - --image gcr.io/kpt-fn/set-labels:v0.1.3 -- tier=backend

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

@@ -0,0 +1,27 @@
+# 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/out-of-place-fnchain-unwrap/.expected/config.yaml

@@ -0,0 +1,33 @@
+stdOut: |
+  apiVersion: apps/v1
+  kind: Deployment
+  metadata:
+    name: nginx-deployment
+    namespace: staging
+    labels:
+      tier: backend
+    annotations:
+      foo: bar
+  spec:
+    replicas: 3
+    selector:
+      matchLabels:
+        tier: backend
+    template:
+      metadata:
+        labels:
+          tier: backend
+        annotations:
+          foo: bar
+  ---
+  apiVersion: custom.io/v1
+  kind: Custom
+  metadata:
+    name: custom
+    namespace: staging
+    labels:
+      tier: backend
+    annotations:
+      foo: bar
+  spec:
+    image: nginx:1.2.3

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

@@ -0,0 +1,7 @@
+#! /bin/bash
+
+set -eo pipefail
+
+kpt fn eval --image gcr.io/kpt-fn/set-namespace:v0.1.3 -o stdout -- namespace=staging \
+| kpt fn eval - --image gcr.io/kpt-fn/set-annotations:v0.1.3 -- foo=bar \
+| kpt fn eval - --image gcr.io/kpt-fn/set-labels:v0.1.3 -o unwrap -- tier=backend

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

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

e2e/testdata/fn-eval/out-of-place-fnchain-unwrap/Kptfile

@@ -0,0 +1,9 @@
+apiVersion: kpt.dev/v1alpha2
+kind: Kptfile
+metadata:
+  name: app
+pipeline:
+  mutators:
+    - image: gcr.io/kpt-fn/set-namespace:v0.1.3
+      configMap:
+        namespace: staging

e2e/testdata/fn-eval/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-eval/out-of-place-source-sink/.expected/diff.patch

@@ -0,0 +1,34 @@
+diff --git a/out/resources.yaml b/out/resources.yaml
+new file mode 100644
+index 0000000..254b9cd
+--- /dev/null
++++ b/out/resources.yaml
+@@ -0,0 +1,28 @@
++# 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
++  namespace: staging
++spec:
++  replicas: 3
++---
++apiVersion: custom.io/v1
++kind: Custom
++metadata:
++  name: custom
++  namespace: staging
++spec:
++  image: nginx:1.2.3

e2e/testdata/fn-eval/out-of-place/.expected/exec.sh → e2e/testdata/fn-eval/out-of-place-source-sink/.expected/exec.sh

@@ -15,16 +15,8 @@
 
 set -eo pipefail
 
-# create a temporary directory
-TEMP_DIR=$(mktemp -d)
+rm -rf out; mkdir out
 
 kpt fn source \
 | kpt fn eval - --image gcr.io/kpt-fn/set-namespace:v0.1.3 -- namespace=staging \
-| kpt fn sink $TEMP_DIR
-
-# copy back the resources
-rm -r ./*
-cp $TEMP_DIR/* .
-
-# remove temporary directory
-rm -r $TEMP_DIR
+| kpt fn sink out

e2e/testdata/fn-eval/out-of-place-source-sink/.krmignore

@@ -0,0 +1,2 @@
+.expected
+out

e2e/testdata/fn-eval/out-of-place-source-sink/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/output-to-stdout/.expected/config.yaml

@@ -13,35 +13,39 @@
 # limitations under the License.
 
 stdOut: |
-  # 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
-    namespace: staging
-    annotations:
-      config.kubernetes.io/path: resources.yaml
-  spec:
-    replicas: 3
-  ---
-  apiVersion: custom.io/v1
-  kind: Custom
-  metadata:
-    name: custom
-    namespace: staging
-    annotations:
-      config.kubernetes.io/path: resources.yaml
-  spec:
-    image: nginx:1.2.3
+  apiVersion: config.kubernetes.io/v1alpha1
+  kind: ResourceList
+  items:
+    - # 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
+        namespace: staging
+        annotations:
+          config.kubernetes.io/index: "0"
+          config.kubernetes.io/path: resources.yaml
+      spec:
+        replicas: 3
+    - apiVersion: custom.io/v1
+      kind: Custom
+      metadata:
+        name: custom
+        namespace: staging
+        annotations:
+          config.kubernetes.io/index: "1"
+          config.kubernetes.io/path: resources.yaml
+      spec:
+        image: nginx:1.2.3