Group common initialisation logic, DI container and config in a python module

Author: febus982

.coveragerc

@@ -1,7 +1,7 @@
 [run]
 branch = True
-source = http_app, grpc_app, domains, gateways, celery_worker
-omit = grpc_app/generated/*
+source = http_app, grpc_app, domains, gateways, celery_worker, common
+omit = grpc_app/generated/*, common/config.py
 concurrency = multiprocessing
 parallel = true
 

Dockerfile

@@ -70,8 +70,7 @@ COPY --chown=nonroot:nonroot poetry.lock .
 COPY --chown=nonroot:nonroot alembic ./alembic
 COPY --chown=nonroot:nonroot domains ./domains
 COPY --chown=nonroot:nonroot gateways ./gateways
-COPY --chown=nonroot:nonroot config.py .
-COPY --chown=nonroot:nonroot di_container.py .
+COPY --chown=nonroot:nonroot common ./common
 COPY --chown=nonroot:nonroot alembic.ini .
 COPY --chown=nonroot:nonroot Makefile .
 

alembic/env.py

@@ -4,19 +4,12 @@
 from sqlalchemy.ext.asyncio import AsyncEngine
 
 from alembic import context
-from config import AppConfig, init_logger
-from gateways.storage.SQLAlchemy import init_tables
+from common.bootstrap import application_init
+from common.config import AppConfig
 
 USE_TWOPHASE = False
 
 
-def init_container(app_config: AppConfig):
-    # Workaround to avoid circular import
-    from di_container import Container
-
-    return Container(config=app_config)
-
-
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.
 config = context.config
@@ -31,13 +24,9 @@ def init_container(app_config: AppConfig):
 # in the sample .ini file.
 # db_names = config.get_main_option("databases")
 
-# TODO: Something better organised than this
-app_config = AppConfig()
-init_logger(app_config)
+di_container = application_init(AppConfig()).di_container
 logger = logging.getLogger("alembic.env")
-di_container = init_container(app_config)
 sa_manager = di_container.SQLAlchemyBindManager()
-init_tables()
 
 target_metadata = sa_manager.get_bind_mappers_metadata()
 db_names = target_metadata.keys()

architecture.puml

@@ -17,6 +17,11 @@ package domains #DDDDDD {
 
         package entities {
             class BookModel
+            class BookEvent
+        }
+
+        package tasks {
+            class BookTask
         }
 
         package data_access_interface {
@@ -41,6 +46,7 @@ servicers --> Book
 'links internal to books domain
 BookService -l-> Book
 BookService --> entities
+BookService --> tasks
 BookService -r-> data_access_interface
 data_access_interface --> entities
 

celery_worker/__init__.py

@@ -3,12 +3,7 @@
 application layers (storage, logs) when running standalone workers
 without having to initialise the HTTP framework (or other ones)
 """
-from config import AppConfig, init_logger
-from domains import init_celery, init_domains
-from gateways.storage import init_storage
+from common.bootstrap import application_init
+from common.config import AppConfig
 
-app_config = AppConfig()
-init_logger(app_config)
-init_domains(app_config)
-init_storage()
-app = init_celery(app_config)
+app = application_init(AppConfig()).celery_app

common/__init__.py

@@ -0,0 +1,32 @@
+from celery import Celery
+from dependency_injector.containers import DynamicContainer
+from dependency_injector.providers import Object
+from pydantic import BaseModel, ConfigDict
+
+from domains import init_celery, init_domains
+from gateways.storage import init_storage
+
+from .config import AppConfig, init_logger
+from .di_container import Container
+
+
+class InitReference(BaseModel):
+    celery_app: Celery
+    di_container: DynamicContainer
+
+    model_config = ConfigDict(arbitrary_types_allowed=True)
+
+
+def application_init(app_config: AppConfig) -> InitReference:
+    container = Container(
+        config=Object(app_config),
+    )
+    init_logger(app_config)
+    init_domains(app_config)
+    init_storage()
+    celery = init_celery(app_config)
+
+    return InitReference(
+        celery_app=celery,
+        di_container=container,
+    )

common/bootstrap.py

@@ -3,7 +3,7 @@
 from sqlalchemy_bind_manager import SQLAlchemyBindManager
 from sqlalchemy_bind_manager._repository import SQLAlchemyAsyncRepository
 
-from config import AppConfig
+from common.config import AppConfig
 from domains.books._data_access_interfaces import (
     BookEventGatewayInterface,
     BookRepositoryInterface,

config.py renamed to common/config.py

@@ -1,8 +1,8 @@
 from celery import Celery
 from dependency_injector.providers import Object
 
-from config import AppConfig
-from di_container import Container
+from common.config import AppConfig
+from common.di_container import Container
 
 
 def init_domains(config: AppConfig):