Remove kernel-upgrade role (#1798)

This role only support Red Hat type distros and is not maintained
or used by many users. It should be removed because it creates
feature disparity between supported OSes and is not maintained.

cluster.yml

@@ -26,7 +26,6 @@
   any_errors_fatal: "{{ any_errors_fatal | default(true) }}"
   roles:
     - { role: kubespray-defaults}
-    - { role: kernel-upgrade, tags: kernel-upgrade, when: kernel_upgrade is defined and kernel_upgrade }
     - { role: kubernetes/preinstall, tags: preinstall }
     - { role: docker, tags: docker }
     - role: rkt

inventory/group_vars/all.yml

@@ -114,9 +114,6 @@ bin_dir: /usr/local/bin
 ## as a backend). Options are "script" or "vault"
 #cert_management: script
 
-## Please specify true if you want to perform a kernel upgrade
-kernel_upgrade: false
-
 # Set to true to allow pre-checks to fail and continue deployment
 #ignore_assert_errors: false
 

roles/kernel-upgrade/defaults/main.yml

----
-elrepo_key_url: 'https://www.elrepo.org/RPM-GPG-KEY-elrepo.org'
-elrepo_rpm: elrepo-release-7.0-3.el7.elrepo.noarch.rpm
-elrepo_mirror: http://www.elrepo.org
-
-elrepo_url: '{{elrepo_mirror}}/{{elrepo_rpm}}'
-
-elrepo_kernel_package: "kernel-lt"

roles/kernel-upgrade/tasks/centos-7.yml

----
-
-- name: install ELRepo key
-  rpm_key:
-    state: present
-    key: '{{ elrepo_key_url }}'
-
-- name: install elrepo repository
-  yum:
-    name: '{{elrepo_url}}'
-    state: present
-
-- name: upgrade kernel
-  yum:
-    name: "{{elrepo_kernel_package}}"
-    state: present
-    enablerepo: elrepo-kernel
-  register: upgrade
-
-- name: change default grub entry
-  lineinfile:
-    dest: '/etc/default/grub'
-    regexp: '^GRUB_DEFAULT=.*'
-    line: 'GRUB_DEFAULT=0'
-  when: upgrade.changed
-  register: grub_entry
-
-- name: re-generate grub-config
-  command: grub2-mkconfig -o /boot/grub2/grub.cfg
-  when: upgrade.changed and grub_entry.changed
-
-- include: reboot.yml
-  when: upgrade.changed
\ No newline at end of file

roles/kernel-upgrade/tasks/main.yml

----
-
-- include: centos-7.yml
-  when: ansible_distribution in ["CentOS","RedHat"] and
-        ansible_distribution_major_version >= 7 and not is_atomic
\ No newline at end of file

roles/kernel-upgrade/tasks/reboot.yml

----
-
-# Reboot the machine gets more complicated as we want to support bastion hosts. A simple wait_for task would not work
-# as we can not directly reach the hosts (except the bastion). In case a basion is used, we first check for it to come
-# back. After it is back, we check for all the hosts by delegating to the bastion.
-
-- name: Rebooting server
-  shell: nohup bash -c "sleep 5 && shutdown -r now 'Reboot required for updated kernel'" &
-
-- name: Wait for some seconds
-  pause:
-    seconds: 10
-
-- set_fact:
-    is_bastion: "{{ inventory_hostname == 'bastion' }}"
-    wait_for_delegate: "localhost"
-
-- set_fact:
-    wait_for_delegate: "{{hostvars['bastion']['ansible_ssh_host']}}"
-  when: "'bastion' in groups['all']"
-
-- name: wait for bastion to come back
-  wait_for:
-    host: "{{ ansible_ssh_host }}"
-    port: 22
-    delay: 10
-    timeout: 300
-  become: false
-  delegate_to: localhost
-  when: is_bastion
-
-- name: waiting for server to come back (using bastion if necessary)
-  wait_for:
-    host: "{{ ansible_ssh_host }}"
-    port: 22
-    delay: 10
-    timeout: 300
-  become: false
-  delegate_to: "{{ wait_for_delegate }}"
-  when: not is_bastion

scale.yml

@@ -22,7 +22,6 @@
   any_errors_fatal: "{{ any_errors_fatal | default(true) }}"
   roles:
     - { role: kubespray-defaults}
-    - { role: kernel-upgrade, tags: kernel-upgrade, when: kernel_upgrade is defined and kernel_upgrade }
     - { role: kubernetes/preinstall, tags: preinstall }
     - { role: docker, tags: docker }
     - role: rkt

upgrade-cluster.yml

@@ -26,7 +26,6 @@
   any_errors_fatal: "{{ any_errors_fatal | default(true) }}"
   roles:
     - { role: kubespray-defaults}
-    - { role: kernel-upgrade, tags: kernel-upgrade, when: kernel_upgrade is defined and kernel_upgrade }
     - { role: kubernetes/preinstall, tags: preinstall }
     - { role: docker, tags: docker }
     - role: rkt