Configuration for multiple databases with rails-CodePudding

A Rails 7.0.3 application has the following database.yml configuration, with the default block generated by the rails app initialisation process.

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  timeout: 5000

development:
  <<: *default
  primary:
    database: user_development
    username: deploy_root
    password: password
    host: "localhost"
    migrations_paths: db/user_migrate
  primary_replica:
    database: user_development
    username: deploy_readonly
    password: password
    host: "localhost"
    replica: true
  forum:
    database: forum_development
    username: deploy_root
    password: password
    host: "localhost"
    migrations_paths: db/forum_migrate
  forum_replica:
    database: forum_development
    username: deploy_readonly
    password: password
    host: "localhost"
    replica: true
  office:
    database: office_development
    username: deploy_root
    password: password
    host: "localhost"
    migrations_paths: db/office_migrate

test:
  <<: *default
  primary:
    database: user_test
    username: deploy_root
  primary_replica:
    database: user_test
    username: deploy_readonly
  forum:
    database: forum_test
    username: deploy_root
  forum_replica:
    database: forum_test
    username: deploy_readonly
  office:
    database: office_test
    username: deploy_root

  <<: *default
  primary:
    host: 'primary.domain.ws'
    username: deploy_root
    password: [omiss]
    database: user_production
    pool: 50
    timeout: 5000
  primary_replica:
    host: 'replica.domain.ws'
    username: deploy_readonly
    password: [omiss]
    database: user_production
    pool: 50
    timeout: 5000
    replica: true
  forum:
    database: forum_production
    username: deploy_root
    password: [omiss]
    host: 'forum.domain.ws'
    migrations_paths: db/forum_migrate
  forum_replica:
    database: forum_production
    username: deploy_readonly
    password: [omiss]
    host: 'forumreplica.domain.ws'
    replica: true
  office:
    database: office_production
    username: deploy_root
    password: [omiss]
    host: 'office.domain.ws'
    migrations_paths: db/office_migrate

However, upon running bin/rails db:create the application complains

no implicit conversion of nil into String
Couldn't create '' database. Please check your configuration.

The syntax is that used in other rails 7 apps, albeit not in partnet/replica contexts and seems to respect the rails guides guidelines.

What is wrong with the above that a string get interpreted as nil?

update If the development block is altered to

development:
  <<: *default
  database: office_development
  username: deploy_root
  password: password
  host: "localhost"
  migrations_paths: db/office_migrate
  primary:
    [...]

the default database is created, but not the main and replicas. thus there is an issue with the YAML structure, although it lints successfully.

CodePudding user response：

The call to shared attributes <<: *default needs to be removed. This will allow processing of development databases.

The attributes

  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

being added to each block.

An additional hang-up was with the test databases, the replicas:

  primary_replica:
    database: user_test
    username: deploy_readonly
  forum_replica:
    database: forum_test
    username: deploy_readonly

needed removing for the process to complete. I surmise that there is the assumption that objects being read from the main copy is the exact same as it being read from the replica and thus this is excessive