kubeadm: allow to provide patch inline in inventories

Specifying one directory for kubeadm patches is not ideal:
1. It does not allow working with multiples inventories easily
2. No ansible templating of the patch
3. Ansible path searching can sometimes be confusing

Instead, provide the patch directly in a variable, and add some quality
of life to handle components targeting and patch ordering more
explicitly (`target` and `type` which are translated to the kubeadm
scheme which is based on the file name)

roles/kubernetes/control-plane/tasks/kubeadm-upgrade.yml

@@ -18,7 +18,7 @@
     --ignore-preflight-errors=all
     --allow-experimental-upgrades
     --etcd-upgrade={{ (etcd_deployment_type == "kubeadm") | bool | lower }}
-    {% if kubeadm_patches is defined and kubeadm_patches.enabled %}--patches={{ kubeadm_patches.dest_dir }}{% endif %}
+    {% if kubeadm_patches | length > 0 %}--patches={{ kubeadm_patches_dir }}{% endif %}
     --force
   register: kubeadm_upgrade
   # Retry is because upload config sometimes fails
@@ -39,7 +39,7 @@
     --ignore-preflight-errors=all
     --allow-experimental-upgrades
     --etcd-upgrade={{ (etcd_deployment_type == "kubeadm") | bool | lower }}
-    {% if kubeadm_patches is defined and kubeadm_patches.enabled %}--patches={{ kubeadm_patches.dest_dir }}{% endif %}
+    {% if kubeadm_patches | length > 0 %}--patches={{ kubeadm_patches_dir }}{% endif %}
     --force
   register: kubeadm_upgrade
   # Retry is because upload config sometimes fails

roles/kubernetes/control-plane/templates/kubeadm-config.v1beta3.yaml.j2

@@ -28,9 +28,9 @@ nodeRegistration:
   kubeletExtraArgs:
     cloud-provider: external
 {% endif %}
-{% if kubeadm_patches is defined and kubeadm_patches.enabled %}
+{% if kubeadm_patches | length > 0 %}
 patches:
-  directory: {{ kubeadm_patches.dest_dir }}
+  directory: {{ kubeadm_patches_dir }}
 {% endif %}
 ---
 apiVersion: kubeadm.k8s.io/v1beta3

roles/kubernetes/control-plane/templates/kubeadm-controlplane.v1beta3.yaml.j2

@@ -31,7 +31,7 @@ nodeRegistration:
 {% else %}
   taints: []
 {% endif %}
-{% if kubeadm_patches is defined and kubeadm_patches.enabled %}
+{% if kubeadm_patches | length > 0 %}
 patches:
-  directory: {{ kubeadm_patches.dest_dir }}
+  directory: {{ kubeadm_patches_dir }}
 {% endif %}

roles/kubernetes/kubeadm/templates/kubeadm-client.conf.v1beta3.j2

@@ -38,7 +38,7 @@ nodeRegistration:
   - effect: NoSchedule
     key: node-role.kubernetes.io/calico-rr
 {% endif %}
-{% if kubeadm_patches is defined and kubeadm_patches.enabled %}
+{% if kubeadm_patches | length > 0 %}
 patches:
-  directory: {{ kubeadm_patches.dest_dir }}
+  directory: {{ kubeadm_patches_dir }}
 {% endif %}

roles/kubernetes/kubeadm_common/defaults/main.yml

+---
+kubeadm_patches_dir: "{{ kube_config_dir }}/patches"
+kubeadm_patches: []
+# kubeadm_patches:
+# - target: kube-apiserver|kube-controller-manager|kube-scheduler|etcd|kubeletconfiguration
+#   type: strategic(default)|json|merge
+#   patch:
+#    metadata:
+#      annotations:
+#        example.com/test: "true"
+#      labels:
+#        example.com/prod_level: "{{ prod_level }}"
+# - ...
+# Patches are applied in the order they are specified.

roles/kubernetes/kubeadm_common/tasks/main.yml

 ---
 - name: Kubeadm | Create directory to store kubeadm patches
   file:
-    path: "{{ kubeadm_patches.dest_dir }}"
+    path: "{{ kubeadm_patches_dir }}"
     state: directory
     mode: "0640"
-  when: kubeadm_patches is defined and kubeadm_patches.enabled
+  when: kubeadm_patches | length > 0
 
 - name: Kubeadm | Copy kubeadm patches from inventory files
   copy:
-    src: "{{ kubeadm_patches.source_dir }}/"
-    dest: "{{ kubeadm_patches.dest_dir }}"
+    content: "{{ item.patch | to_yaml }}"
+    dest: "{{ kubeadm_patches_dir }}/{{ item.target }}{{ suffix }}+{{ item.type | d('strategic') }}.yaml"
     owner: "root"
     mode: "0644"
-  when: kubeadm_patches is defined and kubeadm_patches.enabled
+  loop: "{{ kubeadm_patches }}"
+  loop_control:
+    index_var: suffix