refactor: extract DNS configuration from kubernetes/preinstall into dns_config role (#13603)

Extract tasks related to host DNS management from kubernetes/preinstall
into a new kubernetes/dns_config role.

Previously, kubernetes/preinstall was re-invoked at the end of cluster
playbooks with dns_late: true to apply resolvconf changes after cluster
DNS came up. Because of this reuse, several unrelated tasks in preinstall
were guarded with 'when: not dns_late'.

Move resolvconf, systemd-resolved, networkmanager-dns, and dhclient tasks,
along with their associated templates, facts, variables, and handlers, into
kubernetes/dns_config. Update cluster.yml, upgrade_cluster.yml, scale.yml,
and reset.yml to invoke the new role directly and remove dns_late guards.

Signed-off-by: Dasmat13 <gptdasmat@gmail.com>

roles/kubernetes/preinstall/defaults/main.yml

@@ -3,23 +3,11 @@
 ignore_assert_errors: false
 # Set to false to disable the backup parameter, set to true to accumulate backups of config files.
 leave_etc_backup_files: true
-nameservers: []
-cloud_resolver: []
-disable_host_nameservers: false
-# Kubespray sets this to true after clusterDNS is running to apply changes to the host resolv.conf
-dns_late: false
-# DNS resolver option timeout and retry attempts.
-dns_timeout: 2
-dns_attempts: 2
-
 # Set to true if your network does not support IPv6
 # This may be necessary for pulling Docker images from
 # GCE docker repository
 disable_ipv6_dns: false
 
-# Remove default cluster search domains (``default.svc.{{ dns_domain }}, svc.{{ dns_domain }}``).
-remove_default_searchdomains: false
-
 kube_owner: kube
 kube_cert_group: kube-cert
 kube_config_dir: /etc/kubernetes
@@ -27,10 +15,6 @@ kube_cert_dir: "{{ kube_config_dir }}/ssl"
 kube_cert_compat_dir: /etc/kubernetes/pki
 kubelet_flexvolumes_plugins_dir: /usr/libexec/kubernetes/kubelet-plugins/volume/exec
 
-# Flatcar Container Linux by Kinvolk cloud init config file to define /etc/resolv.conf content
-# for hostnet pods and infra needs
-resolveconf_cloud_init_conf: /etc/resolveconf_cloud_init.conf
-
 # sysctl_file_path to add sysctl conf to
 sysctl_file_path: "/etc/sysctl.d/99-sysctl.conf"
 
@@ -106,9 +90,6 @@ redhat_os_family_extensions:
   - "UnionTech"
   - "UniontechOS"
 
-# Sets DNSStubListener=no, useful if you get "0.0.0.0:53: bind: address already in use"
-systemd_resolved_disable_stub_listener: "{{ ansible_facts['os_family'] == 'Flatcar' }}"
-
 # Used to disable File Access Policy Daemon service.
 # If service is enabled, the CNI plugin installation will fail
 disable_fapolicyd: true