Fix interface lookup

[thesefer]

Description

In https://github.com/mrlesmithjr/ansible-mariadb-galera-cluster/blob/master/templates/etc/mysql/conf.d/galera.cnf.j2 the subvalue of hostvars[node]['ansible_' ~ galera_cluster_bind_interface]['ipv4']['address'] cannot be found because the galera_cluster_bind_interface contains only the interface for the current host. You have to lookup the variable for each host individually.

EDIT:
To be more precise, in it's old form running the template on host 1, the galera_cluster_bind_interface would be eth0 while on the second host it is eth1. The check running on host1 would check hostvars[host1]['ansible_' ~ eth0]['ipv4']['address'] and gets a result but would not get anything for hostvars[host2]['ansible_' ~ eth0]['ipv4']['address'] because eth0 does not exist there. Same vice versa. The galera_cluster_bind_interface is set fixed for the host it is running on.

Related Issue

#243

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (non-breaking change that does not add functionality or fix an issue)

Checklist:

• I have read the CONTRIBUTING document.
• I have run the pre-merge tests locally and they pass.
  Couldn't test properly due to company proxy restrictions.

[eRadical]

This means on each node one has to set "galera_cluster_bind_interface".
I find it rather cumbersome...

I'm also not sure if this is backward compatible.

[thesefer]

I didn't check or change the following occurrences:

roles/mrlesmithjr.mariadb-galera-cluster/templates/etc/my.cnf.d/server.cnf.j2
51:{%   set _ = _galera_cluster_node_addresses.append( hostvars[node]['galera_cluster_bind_address'] | default(hostvars[node]['ansible_' ~ galera_cluster_bind_interface]['ipv4']['address']) | mandatory ) %}

roles/mrlesmithjr.mariadb-galera-cluster/templates/etc/my.cnf.d/server.cnf.temp.j2
51:{%   set _ = _galera_cluster_node_addresses.append( hostvars[node]['galera_cluster_bind_address'] | default(hostvars[node]['ansible_' ~ galera_cluster_bind_interface]['ipv4']['address']) | mandatory ) %}

roles/mrlesmithjr.mariadb-galera-cluster/templates/etc/mysql/conf.d/galera.cnf.temp.j2
51:{%   set _ = _galera_cluster_node_addresses.append( hostvars[node]['galera_cluster_bind_address'] | default(hostvars[node]['ansible_' ~ galera_cluster_bind_interface]['ipv4']['address']) | mandatory ) %}

@eRadical
The default is galera_cluster_bind_interface: "eth0" which wouldn't match either so one has to set it. I worked around this by setting it to the following: galera_cluster_bind_interface: "{{ ansible_default_ipv4['interface'] }}" in my group vars.

[thesefer]

Btw the following default variable isn't working / expanding and needs to be changed according to my tests but is not covered in this PR:

galera_cluster_bind_address: "{{ hostvars[inventory_hostname]['ansible_' + galera_cluster_bind_interface]['ipv4']['address'] }}" to galera_cluster_bind_address: "{{ ansible_default_ipv4['address'] }}"

[thesefer]

I implemented the change to all files considered. I added the example for galera_cluster_bind_interface to the defaults file (which will make it completely dynamic because it is using ansible runtime variables and values) and replaced the +galera_cluster_bind_address to do the same.

Please note that the fix from 0d3180f will not work (Please test it by removing the default completely), you will only get The error was: ansible.errors.AnsibleFilterError: Mandatory variable '10.10.10.0' not defined because it is using the value of the variable.

If one didn't do some weird magic this should be 100% backwards compatible (with all fixes applied) because it is using exactly the same values which ansible would gather anyways.

EDIT: It is completely ok to use jinja2 magic in templates and tasks but better not in host variables.

[eRadical]

Hi @thesefer - please rebase & resolve conflicts so I can give it a run.

[thesefer]

Hi @eRadical. Conflicts resolved.