support "custom-config" option

[james beedy]

Users have expressed a need to add user-custom config to my.cnf. It would be nice if this charm allowed for this (e.g. addition of a "custom-config" charm option.

[james beedy (jamesbeedy)]

As a workaround, I forked this charm and added the following to get the custom-config:

templates/my.cnf

{% if custom_config %}
{% for item in custom_config %}
{{item}}
{% endfor %}
{% endif %}

hooks/percona_hooks.py:render_config()

    if config('custom-config'):
        context['custom_config'] = config('custom-config').split(",")

config.yaml

  custom-config:
    type: string
    default:
    description: |
      Comma delineated custom config to make it to my.cnf
      E.x. `"ft_min_word_len=2,otherconfig=otherval"`

[Mario Splivalo (mariosplivalo)]

Wouldn't it be easier/cleaner to just create a new file and put it in /etc/mysql/conf.d/ directory, if extra configuration (outside of scope of the charm) is needed?

[James Page (james-page)]

Marking this as 'wishlist'; we have a similar 'expert use only' feature in other charms as these type of things allow users to shoot themselves in the foot quite spectacularly. I'd rather see proposal for features which can be expressed as specific configuration options or just good, sane best practices!

[OpenStack Infra (hudson-openstack)]

Change abandoned by james beedy (<email address hidden>) on branch: master
Review: https://review.openstack.org/526493
Reason: per comments, there is a better way for this configuration to be accomplished.