How to describe dynamic config.settings values in schema.yml

Question

I have a module config settings.yml file with a dynamic list of the fields attached to a user entity, eg

archive:
  directory: user-history/archive/
  filename: user-history-archive
  max_cardinality: 5
base_fields:
  uid: true
  name: true
  pass: true
  mail: true
  timezone: true
  status: true
  roles: true
  created: true
  changed: true
  access: true
  login: true
  init: true
  langcode: true
  preferred_langcode: true
  preferred_admin_langcode: true
attached_fields:
  field_alpha_text: 1
  field_beta_term: 1
  field_paragraph: 1
  field_user_story: 1
  user_picture: 0
  field_delta_value: 1
no_change:
  ignore: true
  delete: ''

I am unable to find out how this structure should be described in the module schema.yml file so that config_inspector does not flag the schema as invalid.

I have tried vaiations on

user_history.settings:
  type: config_object
  label: 'User history settings'
  mapping:
    no_change:
      type: mapping
      label: 'No change'
      mapping:
        ignore:
          type: boolean
          label: 'Ignore records with no change'
        delete:
          type: string
          label: 'Delete "no change" records older than'
        batch:
          type: integer
          label: 'Batch size for "no change" record delete'
    base_fields:
      type: mapping
      label: 'Base fields to be tracked'
      mapping:
        uid:
          type: boolean
          label: 'Uid'
        name:
          type: boolean
          label: 'Name'
        pass:
          type: boolean
          label: 'Password'
        mail:
          type: boolean
          label: 'Mail'
        timezone:
          type: boolean
          label: 'Timezone'
        status:
          type: boolean
          label: 'Status'
        roles:
          type: boolean
          label: 'Roles'
        created:
          type: boolean
          label: 'Created'
        changed:
          type: boolean
          label: 'Changed'
        access:
          type: boolean
          label: 'Last access'
        login:
          type: boolean
          label: 'Login'
        init:
          type: boolean
          label: 'Initial mail'
        langcode:
          type: boolean
          label: 'Langcode'
        preferred_langcode:
          type: boolean
          label: 'Preferred langcode'
        preferred_admin_langcode:
          type: boolean
          label: 'Preferred admin langcode'
    attached_fields:
      type: mapping
      label: 'Attached fields to be tracked'
      mapping:
        attached_fields.%key:
          type: integer
          label: [label]
    archive:
      type: mapping
      label: 'Archive settings'
      mapping:
        directory:
          type: string
          label: 'Directory for archive files'
        filename:
          type: string
          label: 'Name for archive files'
        max_cardinality:
          type: integer
          label: 'Maximum field cardinality for separate column values'

but without success.

Any suggestions please?

Answer 1

I think this might be covered under the #Defining a new schema subheading here https://www.drupal.org/docs/drupal-apis/configuration-api/configuration-schemametadata#sequence-definitions

I tried to do this using a mapping type and couldn't get it to work, but switching to a sequence does, because a sequence is for identically typed subkeys, whereas a mapping means you might have different subtypes. When to use mapping or sequence to define an array in a schema file?

For a dynamic mapping, use instead the sequence type:

my_module.settings:
  type: config_object
  label: 'My module settings'
  mapping:
    node_type:
      type: sequence
      label: "List of node types"
      sequence:
        type: string
        label: "Node type key"

This allows arbitrary key -> (string)values beneath the node_type key in your schema.yml