Add e2e test for helmfile-diff with post-renderer

Signed-off-by: Yusuke Kuoka <ykuoka@gmail.com>
Signed-off-by: yxxhero <aiopsclub@163.com>

test/e2e/template/helmfile/testdata/snapshot/postrenderer_diff/config.yaml

@@ -0,0 +1,6 @@
+localDockerRegistry:
+  enabled: true
+  port: 5001
+chartifyTempDir: temp1
+helmfileArgs:
+- diff

test/e2e/template/helmfile/testdata/snapshot/postrenderer_diff/input.yaml

@@ -0,0 +1,43 @@
+helmDefaults:
+  postRenderer: ../../postrenderers/add-cm1.bash
+
+releases:
+- name: foo
+  chart: ../../charts/raw-0.1.0
+  values:
+  - templates:
+    - |
+      apiVersion: v1
+      kind: ConfigMap
+      metadata:
+        name: {{`{{ .Release.Name }}`}}-1
+        namespace: {{`{{ .Release.Namespace }}`}}
+      data:
+        foo: FOO
+    dep:
+      templates:
+      - |
+        apiVersion: v1
+        kind: ConfigMap
+        metadata:
+          name: {{`{{ .Release.Name }}`}}-2
+          namespace: {{`{{ .Release.Namespace }}`}}
+        data:
+          bar: BAR
+  postRenderer: ../../postrenderers/add-cm2.bash
+- name: baz
+  chart: ../../charts/raw-0.1.0
+  values:
+  - templates:
+    - |
+      apiVersion: v1
+      kind: ConfigMap
+      metadata:
+        name: {{`{{ .Release.Name }}`}}-3
+        namespace: {{`{{ .Release.Namespace }}`}}
+      data:
+        baz: BAZ
+  dependencies:
+  - alias: dep
+    chart: oci://localhost:5001/myrepo/raw
+    version: 0.1.0

test/e2e/template/helmfile/testdata/snapshot/postrenderer_diff/output.yaml

@@ -0,0 +1,62 @@
+Building dependency release=foo, chart=../../charts/raw-0.1.0
+Building dependency release=baz, chart=$WD/temp1/baz
+Hang tight while we grab the latest from your chart repositories...
+...Successfully got an update from the "myrepo" chart repository
+...Successfully got an update from the "istio" chart repository
+Update Complete. ⎈Happy Helming!⎈
+Saving 1 charts
+Downloading raw from repo oci://localhost:5001/myrepo
+Pulled: localhost:5001/myrepo/raw:0.1.0
+Digest: $DIGEST
+Deleting outdated charts
+
+Comparing release=foo, chart=../../charts/raw-0.1.0
+********************
+
+	Release was not present in Helm.  Diff will show entire contents as new.
+
+********************
+default, cm2, ConfigMap (v1) has been added:
+- 
++ apiVersion: v1
++ kind: ConfigMap
++ data:
++   two: TWO
++ metadata:
++   name: cm2
+default, foo-1, ConfigMap (v1) has been added:
+- 
++ # Source: raw/templates/resources.yaml
++ apiVersion: v1
++ kind: ConfigMap
++ metadata:
++   name: foo-1
++   namespace: default
++ data:
++   foo: FOO
+
+Comparing release=baz, chart=$WD/temp1/baz
+********************
+
+	Release was not present in Helm.  Diff will show entire contents as new.
+
+********************
+default, baz-3, ConfigMap (v1) has been added:
+- 
++ # Source: raw/templates/resources.yaml
++ apiVersion: v1
++ kind: ConfigMap
++ metadata:
++   name: baz-3
++   namespace: default
++ data:
++   baz: BAZ
+default, cm1, ConfigMap (v1) has been added:
+- 
++ apiVersion: v1
++ kind: ConfigMap
++ data:
++   one: ONE
++ metadata:
++   name: cm1
+