etc_hosts

Populate /etc/hosts with the primary IPv4 addresses or specified addresses of an inventory group or a list of names and addresses. This will overwrite existing entries for hosts in the specified group. In the event of an IP address left without a hostname it will be commented out.

Requirements

Either or both:

• An inventory group with one or more hosts. The hosts don't need an ansible_default_ipv4.address defined if etc_hosts_address is set. One of those values is required to create an entry in /etc/hosts.
• A list of names and addresses.

Role Variables

• etc_hosts_group - This is used to select the group to load into /etc/hosts. Defaults to all.
• etc_hosts_path - The path to the hosts file. Defaults to /etc/hosts
• etc_hosts_localhost_ipv4_address - The IP address to use in the hosts file for the current node. Defaults to 127.0.0.11.
• etc_hosts_suffix - The suffix to add to the hostname (eg .local). Defaults to nothing (an empty string).
• etc_hosts_orphaned_message - The message to leave in the comment for orphaned IP addresses. Defaults Orphaned by Ansible {{ ansible_date_time.iso8601 }}.
• etc_hosts_list - A list of dicts with name and address keys. Defaults to an empty list.
• etc_hosts_group_list - The same as etc_hosts_list but for use in group_vars. Defaults to an empty list.
• etc_hosts_host_list - The same as etc_hosts_list but for use in host_vars. Defaults to an empty list.

Dependencies

None.

Example Playbook

Populate the /etc/hosts file on each machine in group servers with all the IP and hostname pairs of all the machines in group servers.

    - hosts: servers
      vars:
        etc_hosts_group: servers
      roles:
         - haxwithaxe.etc_hosts

Populate the /etc/hosts file on each host with all the IP and hostname pairs given in etc_hosts_list.

    - hosts: all
      vars:
        etc_hosts_list:
          - name: foo
            address: 1.2.3.4
          - name: bar
            address: 2.3.4.5
      roles:
         - haxwithaxe.etc_hosts

Populate the /etc/hosts file on each machine in group servers with the IP and hostname with suffix pairs of all the machines in group servers.

    - hosts: servers
      vars:
        etc_hosts_group: servers
        etc_hosts_suffix: .foo
      roles:
         - haxwithaxe.etc_hosts

Add the IP addresses of the myhosts group to the local /etc/hosts. Facts need to be gathered for hosts not in the group being modified by etc_hosts.

- name: Gather facts for the group you need IPs from (etc_hosts_group)
  hosts: myhosts
  tasks:

- name: Add hosts file entries for hosts in mygroup
  hosts: localhost
  vars:
    etc_hosts_group: myhosts
  roles:
    - haxwithaxe.etc_hosts

To set an IP for a host set etc_hosts_address for the host and that address will be used in other hosts' /etc/hosts. For example:

host_vars/alice.yml

etc_hosts_address: 1.2.3.4

License

GPLv3

Author Information

Created by haxwithaxe