helm: install CRDs from a subchart

PROBLEM: Helm 3 only install CRDs during the chart installation. Both
deletes and upgrades are not handled by Helm 3. It requires manual
intervention. Additionally, it is not possible to template CRDs. This is
especially important when installing the chart with an Argo CD
application.

SOLUTION: add the possibility to install the CRDs from a dependency
subchart. This allows clean uninstall, possibility for automated
upgrades, and templating. This feature comes disabled by default.

closes kubernetes-sigs#1637

Signed-off-by: cmontemuino <[email protected]>

Author: cmontemuino

deployment/helm/node-feature-discovery/Chart.yaml

@@ -13,3 +13,7 @@ keywords:
   - node-labels
 type: application
 version: 0.2.1
+dependencies:
+  - name: crds
+    version: 0.0.0
+    condition: crds.install

deployment/helm/node-feature-discovery/charts/crds/Chart.yaml

@@ -0,0 +1,3 @@
+apiVersion: v2
+name: crds
+version: 0.0.0

deployment/helm/node-feature-discovery/charts/crds/README.md

@@ -0,0 +1,9 @@
+# crds
+
+![Version: 0.0.0](https://img.shields.io/badge/Version-0.0.0-informational?style=flat-square)
+
+## Values
+
+| Key | Type | Default | Description |
+|-----|------|---------|-------------|
+| annotations | object | `{}` | Define annotations for CRDs |

deployment/helm/node-feature-discovery/charts/crds/templates/nfd-api-crds.yaml

@@ -0,0 +1,3 @@
+# -- Define annotations for CRDs
+annotations: {}
+#   argocd.argoproj.io/sync-options: Replace=false,ServerSideApply=true

deployment/helm/node-feature-discovery/charts/crds/values.yaml

@@ -16,6 +16,13 @@ featureGates:
 
 priorityClassName: ""
 
+## Custom resource configuration defined as a dependency chart
+crds:
+  # -- Toggle to install and upgrade CRDs from a subchart. Make sure to use it with `--skip-crds` to avoid conflicts. [More info about limitations on CRDs in Helm 3](https://helm.sh/docs/topics/charts/#limitations-on-crds)
+  install: false
+  # -- Annotations to be added to all CRDs
+  annotations: {}
+
 master:
   enable: true
   extraArgs: []

deployment/helm/node-feature-discovery/values.yaml

@@ -149,6 +149,8 @@ Chart parameters are available.
 
 | Name                                                | Type   | Default                                             | Description                                                                                                                                                                                                  |
 | --------------------------------------------------- | ------ | --------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| `crds.install`                                      | bool   | false                                               | Toggle to install and upgrade CRDs from a subchart. Make sure to use it with `--skip-crds` to avoid conflicts. [More info about limitations on CRDs in Helm 3](https://helm.sh/docs/topics/charts/#limitations-on-crds) |
+| `crds.annotations`                                  | object | {}                                                  | Annotations to be added to all CRDs                                                                                                                                                                          |
 | `image.repository`                                  | string | `{{ site.container_image \| split: ":" \| first }}` | NFD image repository                                                                                                                                                                                         |
 | `image.tag`                                         | string | `{{ site.release }}`                                | NFD image tag                                                                                                                                                                                                |
 | `image.pullPolicy`                                  | string | `Always`                                            | Image pull policy                                                                                                                                                                                            |

docs/deployment/helm.md

@@ -0,0 +1,3 @@
+{{- with .Values.annotations }}
+{{- toYaml . | nindent 4 }}
+{{- end }}

hack/crds.annotations.snippet.txt

@@ -44,6 +44,10 @@ NFD_ROOT=$(realpath $(dirname ${BASH_SOURCE[0]})/..)
 controller-gen object crd output:crd:stdout paths=./api/... > deployment/base/nfd-crds/nfd-api-crds.yaml
 mkdir -p deployment/helm/node-feature-discovery/crds
 cp deployment/base/nfd-crds/nfd-api-crds.yaml deployment/helm/node-feature-discovery/crds
+mkdir -p deployment/helm/node-feature-discovery/charts/crds/templates
+for f in deployment/base/nfd-crds/*-crds.yaml; do
+  sed '/controller-gen.kubebuilder.io\/version/ r hack/crds.annotations.snippet.txt' ${f} > deployment/helm/node-feature-discovery/charts/crds/templates/${f##*/}
+done
 
 # Generate clientset and informers
 mv vendor ${TMP_VENDOR_DIR}