Do not alter etc/hosts (#12382)

This is no longer needed, likely for a long time.

roles/kubernetes/preinstall/defaults/main.yml

@@ -28,28 +28,8 @@ kubelet_flexvolumes_plugins_dir: /usr/libexec/kubernetes/kubelet-plugins/volume/
 # for hostnet pods and infra needs
 resolveconf_cloud_init_conf: /etc/resolveconf_cloud_init.conf
 
-# All inventory hostnames will be written into each /etc/hosts file.
-populate_inventory_to_hosts_file: true
-# K8S Api FQDN will be written into /etc/hosts file.
-populate_loadbalancer_apiserver_to_hosts_file: true
-# etc_hosts_localhost_entries will be written into /etc/hosts file.
-populate_localhost_entries_to_hosts_file: true
-
 sysctl_file_path: "/etc/sysctl.d/99-sysctl.conf"
 
-etc_hosts_localhost_entries:
-  127.0.0.1:
-    expected:
-      - localhost
-      - localhost.localdomain
-  ::1:
-    expected:
-      - localhost6
-      - localhost6.localdomain
-    unexpected:
-      - localhost
-      - localhost.localdomain
-
 # Minimal memory requirement in MB for safety checks
 minimal_node_memory_mb: 1024
 minimal_master_memory_mb: 1500

roles/kubernetes/preinstall/tasks/0090-etchosts.yml

@@ -1,80 +0,0 @@
----
-- name: Hosts | create hosts list from inventory
-  set_fact:
-    etc_hosts_inventory_block: |-
-      {% for item in (groups['k8s_cluster'] + groups['etcd'] | default([]) + groups['calico_rr'] | default([])) | unique %}
-      {{ hostvars[item]['main_access_ip'] }} {{ hostvars[item]['ansible_hostname'] | default(item) }}.{{ dns_domain }} {{ hostvars[item]['ansible_hostname'] | default(item) }}
-      {% if ipv4_stack and ipv6_stack %}
-      {{ hostvars[item]['access_ip6'] | default(hostvars[item]['ip6'] | default(hostvars[item]['ansible_default_ipv6']['address'])) }} {{ hostvars[item]['ansible_hostname'] | default(item) }}.{{ dns_domain }} {{ hostvars[item]['ansible_hostname'] | default(item) }}
-      {% endif %}
-      {% endfor %}
-  delegate_to: localhost
-  connection: local
-  delegate_facts: true
-  run_once: true
-
-- name: Hosts | populate inventory into hosts file
-  blockinfile:
-    path: /etc/hosts
-    block: "{{ hostvars.localhost.etc_hosts_inventory_block }}"
-    state: "{{ 'present' if populate_inventory_to_hosts_file else 'absent' }}"
-    create: true
-    backup: "{{ leave_etc_backup_files }}"
-    unsafe_writes: true
-    marker: "# Ansible inventory hosts {mark}"
-    mode: "0644"
-
-- name: Hosts | populate kubernetes loadbalancer address into hosts file
-  lineinfile:
-    dest: /etc/hosts
-    regexp: ".*{{ apiserver_loadbalancer_domain_name }}$"
-    line: "{{ loadbalancer_apiserver.address }} {{ apiserver_loadbalancer_domain_name }}"
-    state: present
-    backup: "{{ leave_etc_backup_files }}"
-    unsafe_writes: true
-  when:
-    - populate_loadbalancer_apiserver_to_hosts_file
-    - loadbalancer_apiserver is defined
-    - loadbalancer_apiserver.address is defined
-
-- name: Hosts | Update localhost entries in hosts file
-  when: populate_localhost_entries_to_hosts_file
-  block:
-    - name: Hosts | Retrieve hosts file content
-      slurp:
-        src: /etc/hosts
-      register: etc_hosts_content
-
-    - name: Hosts | Extract existing entries for localhost from hosts file
-      set_fact:
-        etc_hosts_localhosts_dict: >-
-          {%- set splitted = (item | regex_replace('[ \t]+', ' ') | regex_replace('#.*$') | trim).split(' ') -%}
-          {{ etc_hosts_localhosts_dict | default({}) | combine({splitted[0]: splitted[1::]}) }}
-      with_items: "{{ (etc_hosts_content['content'] | b64decode).splitlines() }}"
-      when:
-        - etc_hosts_content.content is defined
-        - (item is match('^::1 .*') or item is match('^127.0.0.1 .*'))
-
-    - name: Hosts | Update target hosts file entries dict with required entries
-      set_fact:
-        etc_hosts_localhosts_dict_target: >-
-          {%- set target_entries = (etc_hosts_localhosts_dict | default({})).get(item.key, []) | difference(item.value.get('unexpected', [])) -%}
-          {{ etc_hosts_localhosts_dict_target | default({}) | combine({item.key: (target_entries + item.value.expected) | unique}) }}
-      loop: "{{ etc_hosts_localhost_entries | dict2items }}"
-
-    - name: Hosts | Update (if necessary) hosts file
-      lineinfile:
-        dest: /etc/hosts
-        line: "{{ item.key }} {{ item.value | join(' ') }}"
-        regexp: "^{{ item.key }}.*$"
-        state: present
-        backup: "{{ leave_etc_backup_files }}"
-        unsafe_writes: true
-      loop: "{{ etc_hosts_localhosts_dict_target | default({}) | dict2items }}"
-
-# gather facts to update ansible_fqdn
-- name: Update facts
-  setup:
-    gather_subset: min
-  when:
-    - not dns_late

roles/kubernetes/preinstall/tasks/main.yml

@@ -77,12 +77,6 @@
   tags:
     - bootstrap_os
 
-- name: Configure /etc/hosts
-  import_tasks: 0090-etchosts.yml
-  tags:
-    - bootstrap_os
-    - etchosts
-
 - name: Configure dhclient
   import_tasks: 0100-dhclient-hooks.yml
   when:

roles/reset/tasks/main.yml

@@ -395,6 +395,7 @@
     - files
     - dns
 
+  # TODO: remove after release 2.29
 - name: Reset | remove host entries from /etc/hosts
   blockinfile:
     path: "/etc/hosts"