prechecks.yml

---
# A simple playbook with Tendrl installation pre checks as listed in:
# https://tendrl.atlassian.net/browse/TEN-257
# This playbook doesn't modify machines in any way.

- hosts: localhost
  connection: local
  tasks:

    - name: Check if python dns is installed on ansible control machine
      command: python2 -c 'import dns'
      register: python2_c_import_dns
      changed_when: False
      failed_when: python2_c_import_dns.rc > 1

    - name: Abort the playbook if python dns is not installed
      assert:
        that:
          - python2_c_import_dns.rc == 0
        msg: >
          This playbook uses dig lookup module[1], which requires python
          dns module[2] installed[3] on ansible control machine (the
          machine where you run this ansible playbook from).
          [1] https://docs.ansible.com/ansible/latest/playbooks_lookups.html#the-dns-lookup-dig
          [2] http://www.dnspython.org/
          [3] Fedora package: python2-dns, RHEL 7 package: python-dns

#
# Check requirements for *Tendrl Server* only
#

- hosts: tendrl_server
  tags:
    - production
  user: root
  # become: yes
  tasks:

    # Based on Tendrl Server System Requirements
    # From https://github.com/Tendrl/documentation/wiki/Tendrl-release-v1.6.0-(install-guide)#tendrl-server-system-requirements
    - name: Assert that hw requirements are met
      assert:
        that:
          - ansible_memtotal_mb >= 3700
          - ansible_processor_vcpus >= 4

    - name: Check if /var/lib/etcd is a mountpoint
      command: mountpoint /var/lib/etcd
      register: mountpoint_var_lib_etcd
      changed_when: False
      failed_when: mountpoint_var_lib_etcd.rc > 1

    - name: Assert that /var/lib/etcd is a mount point
      assert:
        that:
          - mountpoint_var_lib_etcd.rc == 0
        msg: >
          Directory /var/lib/etcd is not a mountpoint.
          Ensure that Etcd data directory is located on an separate
          dedicated disk which is not being used by any other process
          or the OS.
          See *Tendrl Server System Requirements* section in the
          documentation for more details.

#
# General checks applicable to all machines.
#

- hosts: tendrl_server:gluster_servers
  user: root
  # become: yes
  tasks:

    # example of the transforamtion: "7.10.123" -> "10"
    - name: Extract minor version number from full ansible_distribution_version
      set_fact:
        distribution_minor_version: "{{ ansible_distribution_version|regex_replace('[0-9]\\.([0-9]+).*', '\\1') }}"

    - name: Check that we run on CentOS or Red Hat Enterprise Linux >= 7.6
      assert:
        that:
          - ansible_distribution == "CentOS" or ansible_distribution == "RedHat"
          - ansible_distribution_major_version == '7'
          - distribution_minor_version|int >= 6

    # Checking that NTP is configured. Based on RHEL 7 *System Administrators
    # Guide*.

    - name: Run timedatectl to see if NTP is enabled and synchronized
      command: timedatectl
      changed_when: False
      register: timedatectl_run

    - name: Check that NTP is enabled
      assert:
        that:
          - '"NTP enabled: yes" in timedatectl_run.stdout'

    - name: Check that NTP is synchronized
      assert:
        that:
          - '"NTP synchronized: yes" in timedatectl_run.stdout'

    # Check that hostnames are reachable and available via dns

    # Note that the dns lookup is performed on the ansible control machine (as
    # all ansible lookup plugins are executed locally).
    - name: Check that fqdn of the host is available via dns
      assert:
        that:
          - lookup('dig', ansible_fqdn) != 'NXDOMAIN'

    # This check doesn't use assert, but expects that getent tool ends with
    # nonzero error code when the translation can't be done, so that ansible
    # would consider such state as an failure anyway by default.
    # And again, the implementation is not very efficient (linear check on
    # each machine ... o(n^2)), but here we don't have any other choice: we
    # have to make sure that on each machine, we can get an ip address of all
    # the others to be sure that the dns is configured right.
    - name: Check that the host can get an ip address for all the others
      command: getent hosts "{{ hostvars[item]['ansible_fqdn'] }}"
      changed_when: False
      with_items: "{{ groups['tendrl_server'] + groups['gluster_servers'] }}"