Added custom options in postgresql.conf file

[franzhcs]

Allow custom options to be added to postgresql.conf file

This PR allows deploying custom options that are appended to the postgresql.conf file.

[gclough]

@ElBryan, I'm of two minds about this. It's nice to be able to add custom options if the template is out of date (for example the recently added "data_sync_retry" parameter... but anything that's not a valid GUC will cause PostgreSQL to fail upon startup.

Isn't it a better option to update the template with any missing parameters?

Do you have an example of how this works, and what it fixes?

[franzhcs]

@gclough Albeit agreeing with you, I have also to point out that even with the current template failing at choosing the right value for a parameter yields to the same outcome.

One of the parameters I was looking for was pg_stat_statements.track

[gclough]

@ElBryan , that makes perfect sense. I completely ignored the fact that some extensions have custom GUC's that are not in the standard template.

I get the feeling that these lists could get very long, so should we promote using the dash formatting instead of square brackets? Something like:

postgresql_custom_options:
  - postgresql_custom_option: option_blah_blah
    postgresql_custom_option_value: value_blah_blah

or maybe just a list of tuples to make it less verbose:

postgresql_custom_options:
  - (option_blah_blah, value_blah_blah)

And in the template code, could we use more verbose variable names? ...and spaces around the variable names, to match (mostly) the rest of the role?

{% for option in postgresql_custom_options %}
{% for postgresql_custom_option,postgresql_custom_option_value in option.items() %}
{{ postgresql_custom_option }} = {{ postgresql_custom_option_value }}
{% endfor %}
{% endfor %}

I'm open to ideas, and my only motivation is to make this workable when there are a LOT of parameters.

Finally, could you add in the v10 template code?

Thanks.

[github-actions]

This pr has been marked 'stale' due to lack of recent activity. If there is no further activity, the issue will be closed in another 30 days. Thank you for your contribution!