etcd: deploy container engine if needed (#7532)

If the etcd cluster is separate and the etcd_deployment_type is "host",
there is no need for a container engine on the etcd nodes

Do not rely on a 'default(true)' filter, but define a proper default in
kubespray-defaults depending on etcd deployment method and if internal
or external etcd is used

cluster.yml

@@ -32,7 +32,7 @@
   roles:
     - { role: kubespray-defaults }
     - { role: kubernetes/preinstall, tags: preinstall }
-    - { role: "container-engine", tags: "container-engine", when: deploy_container_engine|default(true) }
+    - { role: "container-engine", tags: "container-engine", when: deploy_container_engine }
     - { role: download, tags: download, when: "not skip_downloads" }
 
 - hosts: etcd

roles/kubespray-defaults/defaults/main.yaml

@@ -244,6 +244,9 @@ kubelet_shutdown_grace_period: 60s
 # to give normal pods time to be gracefully evacuated
 kubelet_shutdown_grace_period_critical_pods: 20s
 
+# Whether to deploy the container engine
+deploy_container_engine: inventory_hostname in groups['k8s_cluster'] or etcd_deployment_type != 'host'
+
 # Container for runtime
 container_manager: docker
 

roles/reset/tasks/main.yml

@@ -100,7 +100,7 @@
   when:
     - crictl.stat.exists
     - container_manager in ["crio", "containerd"]
-    - deploy_container_engine|default(true)
+    - deploy_container_engine
 
 - name: reset | stop and disable crio service
   service:

scale.yml

@@ -53,7 +53,7 @@
   roles:
     - { role: kubespray-defaults }
     - { role: kubernetes/preinstall, tags: preinstall }
-    - { role: container-engine, tags: "container-engine", when: deploy_container_engine|default(true) }
+    - { role: container-engine, tags: "container-engine", when: deploy_container_engine }
     - { role: download, tags: download, when: "not skip_downloads" }
     - { role: etcd, tags: etcd, etcd_cluster_setup: false, when: "not etcd_kubeadm_enabled|default(false)" }
 

upgrade-cluster.yml

@@ -57,7 +57,7 @@
   serial: "{{ serial | default('20%') }}"
   roles:
     - { role: kubespray-defaults }
-    - { role: container-engine, tags: "container-engine", when: deploy_container_engine|default(true) }
+    - { role: container-engine, tags: "container-engine", when: deploy_container_engine }
 
 - hosts: etcd
   gather_facts: False
@@ -94,7 +94,7 @@
   roles:
     - { role: kubespray-defaults }
     - { role: upgrade/pre-upgrade, tags: pre-upgrade }
-    - { role: container-engine, tags: "container-engine", when: deploy_container_engine|default(true) }
+    - { role: container-engine, tags: "container-engine", when: deploy_container_engine }
     - { role: kubernetes/node, tags: node }
     - { role: kubernetes/control-plane, tags: master, upgrade_cluster_setup: true }
     - { role: kubernetes/client, tags: client }
@@ -125,7 +125,7 @@
   roles:
     - { role: kubespray-defaults }
     - { role: upgrade/pre-upgrade, tags: pre-upgrade }
-    - { role: container-engine, tags: "container-engine", when: deploy_container_engine|default(true) }
+    - { role: container-engine, tags: "container-engine", when: deploy_container_engine }
     - { role: kubernetes/node, tags: node }
     - { role: kubernetes/kubeadm, tags: kubeadm }
     - { role: kubernetes/node-label, tags: node-label }