c12s-kubespray/roles/kubernetes/preinstall/tasks/resolvconf.yml
Bogdan Dobrelya a15d626771 Preconfigure DNS stack and docker early
In order to enable offline/intranet installation cases:
* Move DNS/resolvconf configuration to preinstall role. Remove
  skip_dnsmasq_k8s var as not needed anymore.

* Preconfigure DNS stack early, which may be the case when downloading
  artifacts from intranet repositories. Do not configure
  K8s DNS resolvers for hosts /etc/resolv.conf yet early (as they may be
  not existing).

* Reconfigure K8s DNS resolvers for hosts only after kubedns/dnsmasq
  was set up and before K8s apps to be created.

* Move docker install task to early stage as well and unbind it from the
  etcd role's specific install path. Fix external flannel dependency on
  docker role handlers. Also fix the docker restart handlers' steps
  ordering to match the expected sequence (the socket then the service).

* Add default resolver fact, which is
  the cloud provider specific and remove hardcoded GCE resolver.

* Reduce default ndots for hosts /etc/resolv.conf to 2. Multiple search
  domains combined with high ndots values lead to poor performance of
  DNS stack and make ansible workers to fail very often with the
  "Timeout (12s) waiting for privilege escalation prompt:" error.

* Update docs.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>
2016-12-09 17:30:55 +01:00

169 lines
4.6 KiB
YAML

---
- name: check resolvconf
shell: which resolvconf
register: resolvconf
ignore_errors: yes
changed_when: false
tags: facts
- name: check kubelet
stat:
path: "{{ bin_dir }}/kubelet"
register: kubelet
changed_when: false
tags: facts
- name: check if early DNS configuration stage
set_fact:
dns_early: >-
{%- if kubelet.stat.exists -%}false{%- else -%}true{%- endif -%}
tags: facts
- name: target resolv.conf file
set_fact:
resolvconffile: >-
{%- if resolvconf.rc == 0 -%}/etc/resolvconf/resolv.conf.d/head{%- else -%}/etc/resolv.conf{%- endif -%}
when: ansible_os_family != "CoreOS"
tags: facts
- name: target temporary resolvconf cloud init file
set_fact:
resolvconffile: /tmp/resolveconf_cloud_init_conf
when: ansible_os_family == "CoreOS"
tags: facts
- name: create temporary resolveconf cloud init file
command: cp -f /etc/resolv.conf "{{ resolvconffile }}"
when: ansible_os_family == "CoreOS"
- name: generate search domains to resolvconf
set_fact:
searchentries:
"{{ ([ 'default.svc.' + dns_domain, 'svc.' + dns_domain ] + searchdomains|default([])) | join(' ') }}"
tags: facts
- name: decide on dns server IP
set_fact:
dns_server_real: >-
{%- if dns_early|bool -%}{{default_resolver}}{%- else -%}{{dns_server}}{%- endif -%}
- name: pick dnsmasq cluster IP or default resolver
set_fact:
dnsmasq_server: |-
{%- if skip_dnsmasq|bool and not dns_early|bool -%}
{{ [ skydns_server ] + upstream_dns_servers|default([]) }}
{%- elif dns_early|bool -%}
{{ [ dns_server_real ] + upstream_dns_servers|default([]) }}
{%- else -%}
{{ [ dns_server ] }}
{%- endif -%}
tags: facts
- name: generate nameservers to resolvconf
set_fact:
nameserverentries:
"{{ dnsmasq_server|default([]) + nameservers|default([]) }}"
tags: facts
- name: Remove search and nameserver options from resolvconf head
lineinfile:
dest: /etc/resolvconf/resolv.conf.d/head
state: absent
regexp: "^{{ item }}.*$"
backup: yes
follow: yes
with_items:
- search
- nameserver
when: resolvconf.rc == 0
notify: Preinstall | update resolvconf
- name: Remove search and nameserver options from resolvconf cloud init temporary file
lineinfile:
dest: "{{resolvconffile}}"
state: absent
regexp: "^{{ item }}.*$"
backup: yes
follow: yes
with_items:
- search
- nameserver
when: ansible_os_family == "CoreOS"
notify: Preinstall | update resolvconf for CoreOS
- name: Add search domains to resolvconf file
lineinfile:
line: "search {{searchentries}}"
dest: "{{resolvconffile}}"
state: present
insertbefore: BOF
backup: yes
follow: yes
notify: Preinstall | update resolvconf
- name: Add nameservers to resolv.conf
blockinfile:
dest: "{{resolvconffile}}"
block: |-
{% for item in nameserverentries -%}
nameserver {{ item }}
{% endfor %}
state: present
insertafter: "^search default.svc.*$"
create: yes
backup: yes
follow: yes
marker: "# Ansible nameservers {mark}"
notify: Preinstall | update resolvconf
- name: Add options to resolv.conf
lineinfile:
line: options {{ item }}
dest: "{{resolvconffile}}"
state: present
regexp: "^options.*{{ item }}$"
insertafter: EOF
backup: yes
follow: yes
with_items:
- ndots:{{ ndots }}
- timeout:2
- attempts:2
notify: Preinstall | update resolvconf
- name: Remove search and nameserver options from resolvconf base
lineinfile:
dest: /etc/resolvconf/resolv.conf.d/base
state: absent
regexp: "^{{ item }}.*$"
backup: yes
follow: yes
with_items:
- search
- nameserver
when: resolvconf.rc == 0
notify: Preinstall | update resolvconf
- name: disable resolv.conf modification by dhclient
copy: src=dhclient_nodnsupdate dest=/etc/dhcp/dhclient-enter-hooks.d/znodnsupdate mode=0755
notify: Preinstall | restart network
when: ansible_os_family == "Debian"
- name: disable resolv.conf modification by dhclient
copy: src=dhclient_nodnsupdate dest=/etc/dhcp/dhclient.d/nodnsupdate mode=u+x
notify: Preinstall | restart network
when: ansible_os_family == "RedHat"
- name: get temporary resolveconf cloud init file content
command: cat {{ resolvconffile }}
register: cloud_config
when: ansible_os_family == "CoreOS"
- name: persist resolvconf cloud init file
template:
dest: "{{resolveconf_cloud_init_conf}}"
src: resolvconf.j2
owner: root
mode: 0644
notify: Preinstall | update resolvconf for CoreOS
when: ansible_os_family == "CoreOS"