calico: default to using kdd datastore (#6693)

If already deployed, get current datastore from CNI config file

roles/network_plugin/calico/defaults/main.yml

@@ -81,7 +81,7 @@ kube_etcd_cert_file: node-{{ inventory_hostname }}.pem
 kube_etcd_key_file: node-{{ inventory_hostname }}-key.pem
 
 # Choose data store type for calico: "etcd" or "kdd" (kubernetes datastore)
-# The default value calico_datastore: "etcd" is set in role kubespray-default
+# The default value for calico_datastore is set in role kubespray-default
 
 # Use typha (only with kdd)
 typha_enabled: false

roles/network_plugin/calico/tasks/pre.yml

@@ -1,4 +1,20 @@
 ---
+- name: Slurp CNI config
+  slurp:
+    src: /etc/cni/net.d/10-calico.conflist
+  register: calico_cni_config_slurp
+  failed_when: false
+
+- block:
+  - name: Set fact calico_cni_config from slurped CNI config
+    set_fact:
+      calico_cni_config: "{{ calico_cni_config_slurp['content'] | b64decode | from_json }}"
+  - name: Set fact calico_datastore to etcd if needed
+    set_fact:
+      calico_datastore: etcd
+    when: "'etcd_endpoints' in calico_cni_config.plugins.0"
+  when: calico_cni_config_slurp.content is defined
+
 - name: Calico | Get kubelet hostname
   shell: >-
     set -o pipefail && {{ bin_dir }}/kubectl get node -o custom-columns='NAME:.metadata.name,INTERNAL-IP:.status.addresses[?(@.type=="InternalIP")].address'
@@ -8,4 +24,4 @@
   register: calico_kubelet_name
   delegate_to: "{{ groups['kube-master'][0] }}"
   when:
-    - "cloud_provider is defined"
+  - "cloud_provider is defined"