Stricter kubeadm validation (config and runtime checks) (#11710)

* kubeadm: do not ignore preflight errors blindly

The "ignoring all errors" seems to date back to the inception of the
kubeadm support (it was --skip-preflight-check before).

This can mask real errors and prevent users from seeing them.

Do not ignore any errors by default and make the set of ignored errors
configurable.

* download/kubeadm: remove redundant task

The mode is already set by the previous `copy` task.

* Validate kubeadm configs

This should help to fail early when we have invalid kubeadm configs (from
a kubespray bug or a misconfiguration).

* kubeadm-upgrade: remove unnecessary bool cast

* Convert kubeadm join discovery timeout to v1beta4 config

* CI: Ignore kubeadm:Mem errors on some setup.

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

@@ -36,6 +36,7 @@
     dest: "{{ kube_config_dir }}/kubeadm-controlplane.yaml"
     mode: "0640"
     backup: true
+    validate: "{{ bin_dir }}/kubeadm config validate --config %s"
   when:
     - inventory_hostname != first_kube_control_plane
     - not kubeadm_already_run.stat.exists
@@ -87,7 +88,7 @@
   command: >-
     {{ bin_dir }}/kubeadm join
     --config {{ kube_config_dir }}/kubeadm-controlplane.yaml
-    --ignore-preflight-errors=all
+    --ignore-preflight-errors={{ kubeadm_ignore_preflight_errors | join(',') }}
     --skip-phases={{ kubeadm_join_phases_skip | join(',') }}
   environment:
     PATH: "{{ bin_dir }}:{{ ansible_env.PATH }}"

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

@@ -93,6 +93,7 @@
     src: "kubeadm-config.{{ kubeadm_config_api_version }}.yaml.j2"
     dest: "{{ kube_config_dir }}/kubeadm-config.yaml"
     mode: "0640"
+    validate: "{{ bin_dir }}/kubeadm config validate --config %s"
 
 - name: Kubeadm | Create directory to store admission control configurations
   file:
@@ -168,7 +169,7 @@
     timeout -k {{ kubeadm_init_timeout }} {{ kubeadm_init_timeout }}
     {{ bin_dir }}/kubeadm init
     --config={{ kube_config_dir }}/kubeadm-config.yaml
-    --ignore-preflight-errors=all
+    --ignore-preflight-errors={{ kubeadm_ignore_preflight_errors | join(',') }}
     --skip-phases={{ kubeadm_init_phases_skip | join(',') }}
     {{ kube_external_ca_mode | ternary('', '--upload-certs') }}
   register: kubeadm_init

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

@@ -15,9 +15,9 @@
     {{ bin_dir }}/kubeadm
     upgrade apply -y {{ kube_version }}
     --certificate-renewal={{ kubeadm_upgrade_auto_cert_renewal }}
-    --ignore-preflight-errors=all
+    --ignore-preflight-errors={{ kubeadm_ignore_preflight_errors | join(',') }}
     --allow-experimental-upgrades
-    --etcd-upgrade={{ (etcd_deployment_type == "kubeadm") | bool | lower }}
+    --etcd-upgrade={{ (etcd_deployment_type == "kubeadm") | lower }}
     {% if kubeadm_patches | length > 0 %}--patches={{ kubeadm_patches_dir }}{% endif %}
     --force
   register: kubeadm_upgrade
@@ -36,9 +36,9 @@
     {{ bin_dir }}/kubeadm
     upgrade apply -y {{ kube_version }}
     --certificate-renewal={{ kubeadm_upgrade_auto_cert_renewal }}
-    --ignore-preflight-errors=all
+    --ignore-preflight-errors={{ kubeadm_ignore_preflight_errors | join(',') }}
     --allow-experimental-upgrades
-    --etcd-upgrade={{ (etcd_deployment_type == "kubeadm") | bool | lower }}
+    --etcd-upgrade={{ (etcd_deployment_type == "kubeadm") | lower }}
     {% if kubeadm_patches | length > 0 %}--patches={{ kubeadm_patches_dir }}{% endif %}
     --force
   register: kubeadm_upgrade