Split cart into 4 microservices: relations, likes, orders, page-config→blog

Phase 1 - Relations service (internal): owns ContainerRelation, exposes
get-children data + attach/detach-child actions. Retargeted events, blog,
market callers from cart to relations.

Phase 2 - Likes service (internal): unified Like model replaces ProductLike
and PostLike with generic target_type/target_slug/target_id. Exposes
is-liked, liked-slugs, liked-ids data + toggle action.

Phase 3 - PageConfig → blog: moved ownership to blog with direct DB queries,
removed proxy endpoints from cart.

Phase 4 - Orders service (public): owns Order/OrderItem + SumUp checkout
flow. Cart checkout now delegates to orders via create-order action.
Webhook/return routes and reconciliation moved to orders.

Phase 5 - Infrastructure: docker-compose, deploy.sh, Dockerfiles updated
for all 3 new services. Added orders_url helper and factory model imports.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

relations/Dockerfile

@@ -0,0 +1,53 @@
+# syntax=docker/dockerfile:1
+
+FROM python:3.11-slim AS base
+
+ENV PYTHONDONTWRITEBYTECODE=1 \
+    PYTHONUNBUFFERED=1 \
+    PYTHONPATH=/app \
+    PIP_NO_CACHE_DIR=1 \
+    APP_PORT=8000 \
+    APP_MODULE=app:app
+
+WORKDIR /app
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+      ca-certificates \
+      postgresql-client \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY shared/requirements.txt ./requirements.txt
+RUN pip install -r requirements.txt
+
+# Shared code
+COPY shared/ ./shared/
+
+# App code
+COPY relations/ ./
+
+# Sibling models for cross-domain SQLAlchemy imports
+COPY blog/__init__.py     ./blog/__init__.py
+COPY blog/models/         ./blog/models/
+COPY market/__init__.py   ./market/__init__.py
+COPY market/models/       ./market/models/
+COPY cart/__init__.py     ./cart/__init__.py
+COPY cart/models/         ./cart/models/
+COPY events/__init__.py   ./events/__init__.py
+COPY events/models/       ./events/models/
+COPY federation/__init__.py  ./federation/__init__.py
+COPY federation/models/      ./federation/models/
+COPY account/__init__.py  ./account/__init__.py
+COPY account/models/      ./account/models/
+COPY likes/__init__.py ./likes/__init__.py
+COPY likes/models/ ./likes/models/
+COPY orders/__init__.py ./orders/__init__.py
+COPY orders/models/ ./orders/models/
+
+COPY relations/entrypoint.sh /usr/local/bin/entrypoint.sh
+RUN chmod +x /usr/local/bin/entrypoint.sh
+
+RUN useradd -m -u 10001 appuser && chown -R appuser:appuser /app
+USER appuser
+
+EXPOSE ${APP_PORT}
+ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]

relations/alembic.ini

@@ -0,0 +1,35 @@
+[alembic]
+script_location = alembic
+sqlalchemy.url =
+
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s

relations/alembic/env.py

@@ -0,0 +1,12 @@
+from alembic import context
+from shared.db.alembic_env import run_alembic
+
+MODELS = [
+    "shared.models.container_relation",
+]
+
+TABLES = frozenset({
+    "container_relations",
+})
+
+run_alembic(context.config, MODELS, TABLES)

relations/alembic/versions/0001_initial.py

@@ -0,0 +1,49 @@
+"""Initial relations tables
+
+Revision ID: relations_0001
+Revises: None
+Create Date: 2026-02-27
+"""
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = "relations_0001"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def _table_exists(conn, name):
+    result = conn.execute(sa.text(
+        "SELECT 1 FROM information_schema.tables WHERE table_schema='public' AND table_name=:t"
+    ), {"t": name})
+    return result.scalar() is not None
+
+
+def upgrade():
+    if _table_exists(op.get_bind(), "container_relations"):
+        return
+
+    op.create_table(
+        "container_relations",
+        sa.Column("id", sa.Integer, primary_key=True, autoincrement=True),
+        sa.Column("parent_type", sa.String(32), nullable=False),
+        sa.Column("parent_id", sa.Integer, nullable=False),
+        sa.Column("child_type", sa.String(32), nullable=False),
+        sa.Column("child_id", sa.Integer, nullable=False),
+        sa.Column("sort_order", sa.Integer, nullable=False, server_default="0"),
+        sa.Column("label", sa.String(255), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
+        sa.Column("deleted_at", sa.DateTime(timezone=True), nullable=True),
+        sa.UniqueConstraint(
+            "parent_type", "parent_id", "child_type", "child_id",
+            name="uq_container_relations_parent_child",
+        ),
+    )
+    op.create_index("ix_container_relations_parent", "container_relations", ["parent_type", "parent_id"])
+    op.create_index("ix_container_relations_child", "container_relations", ["child_type", "child_id"])
+
+
+def downgrade():
+    op.drop_table("container_relations")

relations/app.py

@@ -0,0 +1,22 @@
+from __future__ import annotations
+import path_setup  # noqa: F401
+
+from shared.infrastructure.factory import create_base_app
+
+from bp import register_actions, register_data
+from services import register_domain_services
+
+
+def create_app() -> "Quart":
+    app = create_base_app(
+        "relations",
+        domain_services_fn=register_domain_services,
+    )
+
+    app.register_blueprint(register_actions())
+    app.register_blueprint(register_data())
+
+    return app
+
+
+app = create_app()

relations/bp/__init__.py

@@ -0,0 +1,2 @@
+from .data.routes import register as register_data
+from .actions.routes import register as register_actions

relations/bp/actions/routes.py

@@ -0,0 +1,78 @@
+"""Relations app action endpoints."""
+from __future__ import annotations
+
+from quart import Blueprint, g, jsonify, request
+
+from shared.infrastructure.actions import ACTION_HEADER
+
+
+def register() -> Blueprint:
+    bp = Blueprint("actions", __name__, url_prefix="/internal/actions")
+
+    @bp.before_request
+    async def _require_action_header():
+        if not request.headers.get(ACTION_HEADER):
+            return jsonify({"error": "forbidden"}), 403
+        from shared.infrastructure.internal_auth import validate_internal_request
+        if not validate_internal_request():
+            return jsonify({"error": "forbidden"}), 403
+
+    _handlers: dict[str, object] = {}
+
+    @bp.post("/<action_name>")
+    async def handle_action(action_name: str):
+        handler = _handlers.get(action_name)
+        if handler is None:
+            return jsonify({"error": "unknown action"}), 404
+        try:
+            result = await handler()
+            return jsonify(result)
+        except Exception as exc:
+            import logging
+            logging.getLogger(__name__).exception("Action %s failed", action_name)
+            return jsonify({"error": str(exc)}), 500
+
+    # --- attach-child ---
+    async def _attach_child():
+        """Create or revive a ContainerRelation."""
+        from shared.services.relationships import attach_child
+
+        data = await request.get_json(force=True)
+        rel  = await attach_child(
+            g.s,
+            parent_type=data["parent_type"],
+            parent_id=data["parent_id"],
+            child_type=data["child_type"],
+            child_id=data["child_id"],
+            label=data.get("label"),
+            sort_order=data.get("sort_order"),
+        )
+        return {
+            "id":          rel.id,
+            "parent_type": rel.parent_type,
+            "parent_id":   rel.parent_id,
+            "child_type":  rel.child_type,
+            "child_id":    rel.child_id,
+            "sort_order":  rel.sort_order,
+        }
+
+    _handlers["attach-child"] = _attach_child
+
+    # --- detach-child ---
+    async def _detach_child():
+        """Soft-delete a ContainerRelation."""
+        from shared.services.relationships import detach_child
+
+        data    = await request.get_json(force=True)
+        deleted = await detach_child(
+            g.s,
+            parent_type=data["parent_type"],
+            parent_id=data["parent_id"],
+            child_type=data["child_type"],
+            child_id=data["child_id"],
+        )
+        return {"deleted": deleted}
+
+    _handlers["detach-child"] = _detach_child
+
+    return bp

relations/bp/data/routes.py

@@ -0,0 +1,56 @@
+"""Relations app data endpoints."""
+from __future__ import annotations
+
+from quart import Blueprint, g, jsonify, request
+
+from shared.infrastructure.data_client import DATA_HEADER
+
+
+def register() -> Blueprint:
+    bp = Blueprint("data", __name__, url_prefix="/internal/data")
+
+    @bp.before_request
+    async def _require_data_header():
+        if not request.headers.get(DATA_HEADER):
+            return jsonify({"error": "forbidden"}), 403
+        from shared.infrastructure.internal_auth import validate_internal_request
+        if not validate_internal_request():
+            return jsonify({"error": "forbidden"}), 403
+
+    _handlers: dict[str, object] = {}
+
+    @bp.get("/<query_name>")
+    async def handle_query(query_name: str):
+        handler = _handlers.get(query_name)
+        if handler is None:
+            return jsonify({"error": "unknown query"}), 404
+        result = await handler()
+        return jsonify(result)
+
+    # --- get-children ---
+    async def _get_children():
+        """Return ContainerRelation children for a parent."""
+        from shared.services.relationships import get_children
+
+        parent_type = request.args.get("parent_type", "")
+        parent_id   = request.args.get("parent_id", type=int)
+        child_type  = request.args.get("child_type")
+        if not parent_type or parent_id is None:
+            return []
+        rels = await get_children(g.s, parent_type, parent_id, child_type)
+        return [
+            {
+                "id":          r.id,
+                "parent_type": r.parent_type,
+                "parent_id":   r.parent_id,
+                "child_type":  r.child_type,
+                "child_id":    r.child_id,
+                "sort_order":  r.sort_order,
+                "label":       r.label,
+            }
+            for r in rels
+        ]
+
+    _handlers["get-children"] = _get_children
+
+    return bp

relations/entrypoint.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Optional: wait for Postgres to be reachable
+if [[ -n "${DATABASE_HOST:-}" && -n "${DATABASE_PORT:-}" ]]; then
+  echo "Waiting for Postgres at ${DATABASE_HOST}:${DATABASE_PORT}..."
+  for i in {1..60}; do
+    (echo > /dev/tcp/${DATABASE_HOST}/${DATABASE_PORT}) >/dev/null 2>&1 && break || true
+    sleep 1
+  done
+fi
+
+# Create own database + run own migrations
+if [[ "${RUN_MIGRATIONS:-}" == "true" && -n "${ALEMBIC_DATABASE_URL:-}" ]]; then
+  python3 -c "
+import os, re
+url = os.environ['ALEMBIC_DATABASE_URL']
+m = re.match(r'postgresql\+\w+://([^:]+):([^@]+)@([^:]+):(\d+)/(.+)', url)
+if not m:
+    print('Could not parse ALEMBIC_DATABASE_URL, skipping DB creation')
+    exit(0)
+user, password, host, port, dbname = m.groups()
+
+import psycopg
+conn = psycopg.connect(
+    f'postgresql://{user}:{password}@{host}:{port}/postgres',
+    autocommit=True,
+)
+cur = conn.execute('SELECT 1 FROM pg_database WHERE datname = %s', (dbname,))
+if not cur.fetchone():
+    conn.execute(f'CREATE DATABASE {dbname}')
+    print(f'Created database {dbname}')
+else:
+    print(f'Database {dbname} already exists')
+conn.close()
+" || echo "DB creation failed (non-fatal), continuing..."
+
+  echo "Running relations Alembic migrations..."
+  if [ -d relations ]; then (cd relations && alembic upgrade head); else alembic upgrade head; fi
+fi
+
+# Clear Redis page cache on deploy
+if [[ -n "${REDIS_URL:-}" && "${REDIS_URL}" != "no" ]]; then
+  echo "Flushing Redis cache..."
+  python3 -c "
+import redis, os
+r = redis.from_url(os.environ['REDIS_URL'])
+r.flushdb()
+print('Redis cache cleared.')
+" || echo "Redis flush failed (non-fatal), continuing..."
+fi
+
+# Start the app
+RELOAD_FLAG=""
+if [[ "${RELOAD:-}" == "true" ]]; then
+  RELOAD_FLAG="--reload"
+  echo "Starting Hypercorn (${APP_MODULE:-app:app}) with auto-reload..."
+else
+  echo "Starting Hypercorn (${APP_MODULE:-app:app})..."
+fi
+PYTHONUNBUFFERED=1 exec hypercorn "${APP_MODULE:-app:app}" --bind 0.0.0.0:${PORT:-8000} --workers ${WORKERS:-2} --keep-alive 75 ${RELOAD_FLAG}

relations/models/__init__.py

@@ -0,0 +1 @@
+from shared.models.container_relation import ContainerRelation

relations/path_setup.py

@@ -0,0 +1,9 @@
+import sys
+import os
+
+_app_dir = os.path.dirname(os.path.abspath(__file__))
+_project_root = os.path.dirname(_app_dir)
+
+for _p in (_project_root, _app_dir):
+    if _p not in sys.path:
+        sys.path.insert(0, _p)

relations/services/__init__.py

@@ -0,0 +1,6 @@
+"""Relations app service registration."""
+from __future__ import annotations
+
+
+def register_domain_services() -> None:
+    """Register services for the relations app."""