# =============================================================================
# shared-memory — external Postgres override.
#
# Use this override when you want to point the app at a managed Postgres
# (AWS RDS, GCP Cloud SQL, Azure Database for PostgreSQL, your own VM, ...)
# instead of the bundled `db` container.
#
# Invocation (always together with the base file):
#
#     docker compose -f docker-compose.yml -f docker-compose.external-db.yml up -d
#
# The caller MUST set `DATABASE_URL` explicitly in `.env` so that `migrator`
# and `app` know where to connect. The `POSTGRES_*` variables are not used
# in this mode (the bundled `db` service is disabled below). Example:
#
#     DATABASE_URL=postgres://memory:STRONG_PASSWORD@your-rds.region.rds.amazonaws.com:5432/memory?sslmode=require
#
# The DB user needs privileges to `CREATE EXTENSION` for pgvector, pg_trgm,
# and pgcrypto on first run — on RDS that means the `rds_superuser` role, or
# pre-create the extensions yourself. See README "External Postgres".
#
# REQUIRES DOCKER COMPOSE >= 2.24.0 (Docker Desktop >= 4.25, or Compose plugin
# 2.24.0+). The `!override` YAML tag on the depends_on blocks below is what
# fully replaces — rather than merges — the base file's `depends_on: db`
# entries. On older Compose the tag is silently ignored, the `db` dependency
# survives the merge, and startup fails with "depends on undefined service
# db". Check with: docker compose version
# =============================================================================

services:
  db:
    # Park the bundled DB on a profile that nothing ever enables. Compose
    # only starts services whose profile list is empty OR matches a
    # `--profile` flag on the command line. "never" is not a magic name —
    # it's just a label we promise not to pass, so the service stays down.
    profiles: ["never"]

  migrator:
    # Docker compose merges `depends_on` by key — listing `embedder` here
    # alone would keep the base file's `db` entry and break with
    # "depends on undefined service db". The `!override` tag (compose 2.24+)
    # replaces the whole block instead of merging.
    depends_on: !override
      embedder:
        condition: service_healthy
    environment:
      # The base file hardcodes DATABASE_URL to point at the bundled `db`
      # service. Override it to pass through whatever the operator set in
      # `.env` (e.g. an RDS endpoint with sslmode=require).
      DATABASE_URL: ${DATABASE_URL:?DATABASE_URL not set in .env (required with external-db override)}

  app:
    # Same merge caveat as above — fully replace the block, keep embedder
    # and migrator deps.
    depends_on: !override
      embedder:
        condition: service_healthy
      migrator:
        condition: service_completed_successfully
    environment:
      DATABASE_URL: ${DATABASE_URL:?DATABASE_URL not set in .env (required with external-db override)}