Configuring /etc/hosts v23

By default, TPA adds lines to /etc/hosts on the target instances with the IP address and hostnames of every instance in the cluster. This enables the instances to use each other's names for communication within the cluster (for example, in primary_conninfo for Postgres).

You can specify a list of extra_etc_hosts_lines, too:

instances:
- Name: one
  …
  vars:
    extra_etc_hosts_lines:
    - 192.0.2.1 acid.example.com
    - 192.0.2.2 water.example.com

If you don't want any of the default entries, you can specify the complete list of etc_hosts_lines for an instance instead. Add only those lines to /etc/hosts:

instances:
- Name: one
  …
  vars:
    etc_hosts_lines:
    - 192.0.2.1 acid.example.com
    - 192.0.2.2 water.example.com
    - 192.0.2.3 base.example.com

If your /etc/hosts doesn't contain the default entries for instances in the cluster, you need to ensure the names can be resolved in some other way.