Using external managed database

[dipth]

I'm having some trouble getting Kamal to deploy an app that is using an external managed postgres database.
Even though I've configured database.yml and Kamal to set the database connection correctly to the external service, it seems like Rails is trying to connect to Postgres locally in the docker container:

2025-01-10T23:08:45.918129437Z ActiveRecord::ConnectionNotEstablished: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: No such file or directory (ActiveRecord::ConnectionNotEstablished)
2025-01-10T23:08:45.918137157Z 	Is the server running locally and accepting connections on that socket?
2025-01-10T23:08:45.918901195Z 
2025-01-10T23:08:45.918922274Z 
2025-01-10T23:08:45.918928154Z Caused by:
2025-01-10T23:08:45.918932994Z PG::ConnectionBad: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: No such file or directory (PG::ConnectionBad)
2025-01-10T23:08:45.918989594Z 	Is the server running locally and accepting connections on that socket?
2025-01-10T23:08:45.919094434Z 
2025-01-10T23:08:45.919105994Z Tasks: TOP => db:prepare
2025-01-10T23:08:45.919460433Z (See full trace by running task with --trace)
2025-01-10T23:08:47.447250341Z bin/rails aborted!

Here are my relevant config files:

config/deploy.yml

<% require "dotenv"; Dotenv.load(".env") %>

service: my_app
image: my_org/my_app
servers:
  web:
    - <%= ENV["WEB_01_IP"] %>
proxy:
  ssl: true
  host: my_app.com
registry:
  username:
    - KAMAL_REGISTRY_USERNAME
  password:
    - KAMAL_REGISTRY_PASSWORD
env:
  secret:
    - RAILS_MASTER_KEY
    - DATABASE_URL
  clear:
    SOLID_QUEUE_IN_PUMA: true
aliases:
  console: app exec --interactive --reuse "bin/rails console"
  shell: app exec --interactive --reuse "bash"
  logs: app logs -f
  dbc: app exec --interactive --reuse "bin/rails dbconsole"
volumes:
  - "my_app_storage:/rails/storage"
asset_path: /rails/public/assets
builder:
  arch: arm64

.kamal/secrets

SECRETS=$(kamal secrets fetch --adapter 1password --account MYACCOUNT --from org/vault KAMAL_REGISTRY_USERNAME KAMAL_REGISTRY_PASSWORD RAILS_MASTER_KEY DATABASE_URL)
KAMAL_REGISTRY_USERNAME=$(kamal secrets extract KAMAL_REGISTRY_USERNAME ${SECRETS})
KAMAL_REGISTRY_PASSWORD=$(kamal secrets extract KAMAL_REGISTRY_PASSWORD ${SECRETS})
RAILS_MASTER_KEY=$(kamal secrets extract RAILS_MASTER_KEY ${SECRETS})
DATABASE_URL=$(kamal secrets extract DATABASE_URL ${SECRETS})

config/database.yml

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  <% if ENV["DB_HOST"] %>
  host: <%= ENV["DB_HOST"] %>
  username: postgres
  password: postgres
  <% end %>

development:
  <<: *default
  database: my_app_development

test:
  <<: *default
  database: my_app_test

production:
  primary: &primary_production
    <<: *default
    database: my_app_production
    url: <%= ENV["DATABASE_URL"] %>
  cache:
    <<: *primary_production
    database: my_app_production_cache
    migrations_paths: db/cache_migrate
  queue:
    <<: *primary_production
    database: my_app_production_queue
    migrations_paths: db/queue_migrate
  cable:
    <<: *primary_production
    database: my_app_production_cable
    migrations_paths: db/cable_migrate

With this setup Kamal should be pulling the DATABASE_URL value from 1Password and inject it as an environment variable in the container, which should then be used by database.yml, however it seems to be completely ignores.
I've checked and double-checked that the DATABASE_URL entry is correct in 1Password.

[dipth]

I have also verified that the env-file gets created correctly on the filesystem of the host:

root@REDACTED:~# cat ~/.kamal/apps/my_app/env/roles/web.env 
RAILS_MASTER_KEY=REDACTED
DATABASE_URL=postgresql://REDACTED:REDACTED@REDACTED/my_app_production?sslmode=require

[dipth]

I was able to resolve the issue by manually removing the .kamal directory on the server then run kamal remove and kamal setup