How to prevent emails, api keys hashes, being stored in config and instead use a non-git controlled env-specific settings.php file instead for them

Question

Background

I want to make my site code open source, for reasons of:

• collaboration
• developing an open source Drupal distribution or module (yes I know distributions might be superseded by recipes but that is still a work in progress)
• (other reasons not applicable to me, but good reasons): public sector / government requirement

Problem

In wanting to open source my code, I notice that my config export as code (yaml) contains personal email addresses. I want to stop this happening but for my working site to still function. So I want to store them outside of git-version controlled config.

Specific examples of personal emails being stored in config export which will be committed to git:

• Site mail address in system.site.yml
• Webform email addresses - in webform.webform.contact.yml:

e.g.

handlers:
  email_confirmation:
    settings:
      to_mail: [email protected]

My question

How can I store specific config items such as email addresses, api keys and hashes outside of git-version controlled config export but still read by Drupal as config?

My research to solve the problem:

I have been unsuccessful, hence asking this question, but here is what I tried.

I tried to apply the following to my own example:

• Override specific configuration keys in settings.local.php
• Configuration override system out of date (even though it says April 2024) because drush config-list is not available in my version of Drush - 12.5 and I've seen an issue/bug to port this into the newer versions of Drush

Here's what I tried to apply - I have my system.site.yml which contains the personal email address which I want to take out of git version controlled config and control in the environment:

_core:
  default_config_hash: (a hash value)
langcode: en
uuid: (a long dash separated hex number)
name: 'My site'
mail: [email protected]
slogan: ''
page:
  403: ''
  404: ''
  front: /node/1
admin_compact_mode: false
weight_select_max: 100
default_langcode: en
mail_notification: ''

Based on the above 2 links to references above, here's my attempt at equivalent config in settings.local.php not stored in git (.gitignore-d), but called from git controlled settings.php

# config/sync/system.site.yml
# mail: [email protected]
$config['system.site']['mail'] = '[email protected]';

(this file also stores my database credentials).

So to try this out, I:

• commented out mail: [email protected] in system.site.yml
• added the config as above to my settings.local.php
• ran drush cim to remove the email from active config, hoping that Drupal would now take it from my settings.local.php
• ran drush cr to clear the cache

Then I visited the Basic site settings page (that uses system.site.yml config): admin/config/system/site-information, but saw that the mail field was empty!

So Drupal wasn't taking the config defined in my settings.local.php.

Further research

From looking at the below links, I'm unclear if general full support is available to override any / all of the configurations in Drupal:

• Allow configuring the environment via an environment variable
  • given that this is an open issue, this seems to contradict the above links I used which had suggested it is already possible
• Set Drupal Configuration with Environment Variables
• Allow configuration via environment variables
• Config Split - I don't think this is relevant to me - Config Split seems to be about - what it say - splitting up config, i.e. a separate place for platform specific config - like enabling the Devel module settings. But in my case, I don't even want email to be in config in the first place. And even if this module was supposed to do what they want, why have this, as well as the other options above?
• Config Ignore - I don't want to ignore yaml files to be imported to prevent overwriting, that's not my problem
• Configuration Management for a Multi-Environment Drupal 8 Development Workflow

Other items (not sure if relevant)

• Environment Variables - not sure if this relates to what I need
• Environment Config
• Drupal 8 Environment Specific Configurations

Research to do - how do distro-makers do it?

• FarmOS
• LocalGovDrupal

I would imagine in their development, they test real sites, with personal settings, but then want to release their work to the public with this data removed, so how do they do it?

Answer 1

Drupal does not show overridden config in the UI; this is very confusing behavior and a 10-year-old core issue. To see overridden config, you need something like the COI module or Config Override Warn module.

How to avoid committing certain config items

Most forms in the Drupal UI have some kind of validation. So, if you are using a standard workflow like drush cex to export config, to generate the config in the first place, you will need to put in valid values (such as an email address).

That means that you can't just put in a value like placeholder for an email address field; you will have to input something like [email protected]. Personally, I would use the same placeholder email everywhere to make it easier to search for later, but any valid email address will do. Alternately, you can input the actual values in the UI, export config, and then edit the exported config to placeholder values, but with that approach there is a higher risk that you will miss something and commit it accidentally.

Then you can override the values in settings.local.php as you described in your question.

If you want to use environment variables instead, that is also possible. But the basic approach for this is the same as using settings.php: you set the config value in settings.php according to the environment variable value read in settings.php, in the way described in this answer, for example.