setup alembic with async

Author: Abdulkbk

alembic.ini

@@ -0,0 +1,103 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration file names; The default value is %%(rev)s_%%(slug)s
+# Uncomment the line below if you want the files to be prepended with date and time
+# file_template = %%(year)d_%%(month).2d_%%(day).2d_%%(hour).2d%%(minute).2d-%%(rev)s_%%(slug)s
+
+# sys.path path, will be prepended to sys.path if present.
+# defaults to the current working directory.
+prepend_sys_path = .
+
+# timezone to use when rendering the date within the migration file
+# as well as the filename.
+# If specified, requires the python-dateutil library that can be
+# installed by adding `alembic[tz]` to the pip requirements
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; This defaults
+# to migrations/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path.
+# The path separator used here should be the separator specified by "version_path_separator" below.
+# version_locations = %(here)s/bar:%(here)s/bat:migrations/versions
+
+# version path separator; As mentioned above, this is the character used to split
+# version_locations. The default within new alembic.ini files is "os", which uses os.pathsep.
+# If this key is omitted entirely, it falls back to the legacy behavior of splitting on spaces and/or commas.
+# Valid values for version_path_separator are:
+#
+# version_path_separator = :
+# version_path_separator = ;
+# version_path_separator = space
+version_path_separator = os  # Use os.pathsep. Default configuration used for new projects.
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+sqlalchemy.url = postgresql+asyncpg://user:pass@localhost:5432/ecommerce
+
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks = black
+# black.type = console_scripts
+# black.entrypoint = black
+# black.options = -l 79 REVISION_SCRIPT_FILENAME
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[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
+datefmt = %H:%M:%S

authentication/crud.py

@@ -0,0 +1,37 @@
+import bcrypt
+from fastapi import Depends, status
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from fastapi_utils.cbv import cbv
+from fastapi_utils.inferring_router import InferringRouter
+from starlette.responses import JSONResponse, Response
+from authentication.models import User, UserCreate
+
+from common.concurrency import cpu_bound_task
+from common.database.db import get_session
+from common.injection import on
+
+
+auth_router = InferringRouter()
+
+
+@cbv(auth_router)
+class AuthCrud:
+
+  @auth_router.post(
+    '/register',
+    status_code=status.HTTP_201_CREATED
+  )
+  async def register(self, user_in: UserCreate, session: AsyncSession = Depends(get_session)):
+    user = User(name=user_in.name, email=user_in.email, password=user_in.password, phone=user_in.phone)
+    user.password = (
+      await cpu_bound_task(
+        bcrypt.hashpw, user.password.encode(), bcrypt.gensalt()
+      )
+    ).decode()
+    session.add(user)
+    await session.commit()
+    await session.refresh(user)
+    return user
+    

authentication/models.py

@@ -0,0 +1,16 @@
+from typing import Optional
+
+from sqlmodel import SQLModel, Field
+
+class UserBase(SQLModel):
+  name: str
+  email: str
+  password: str
+  phone: str
+
+class User(UserBase, table=True):
+  id: int = Field(default=None, primary_key=True)
+
+
+class UserCreate(UserBase):
+  pass

common/concurrency.py

@@ -0,0 +1,17 @@
+import asyncio
+from concurrent.futures.thread import ThreadPoolExecutor
+from typing import Callable
+
+
+_executor =ThreadPoolExecutor()
+
+async def cpu_bound_task(func: Callable, *args):
+  """
+    Execute async function in a separate thread, without blocking the main event
+    loop.
+
+    :param func: async function that will be executed in separate thread
+    :param args: async function parameters
+    :return: async function result
+  """
+  return await asyncio.get_event_loop().run_in_executor(_executor, func, *args)

common/config.py

@@ -14,10 +14,11 @@ class DevSettings(Settings):
   prod: bool = True
   fastapi_log_level: str = 'debug'
   domain_name: str = 'http://localhost:8000'
+  database_uri:str = ""
 
 
 class ProdSettings(Settings):
-  prod: False
+  prod: bool = False
   fastapi_log_level: str = 'info'
   domain_name: str = 'http://localhost:8000'
 

common/database/db.py

@@ -0,0 +1,23 @@
+import os
+
+from common.config import cfg
+
+from sqlmodel import SQLModel
+
+from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
+from sqlalchemy.orm import sessionmaker
+
+
+engine = create_async_engine(cfg.database_uri, echo=True, future=True)
+
+async def init_db():
+  async with engine.begin() as conn:
+    await conn.run_sync(SQLModel.metadata.create_all)
+
+
+async def get_session() -> AsyncSession:
+  async_session = sessionmaker(
+    engine, class_ = AsyncSession, expire_on_commit=False
+  )
+  async with async_session() as session:
+    yield session

common/exceptions.py

@@ -0,0 +1,24 @@
+from typing import Any, Dict, Optional
+
+from fastapi import HTTPException
+
+
+class HTTPExceptionJSON(HTTPException):
+    """FastAPI HTTPException enriched with 'code' and 'data' fields, useful to
+    add some context to the error message."""
+
+    def __init__(
+        self,
+        status_code: int,
+        code: str = None,
+        detail: Any = None,
+        headers: Optional[Dict[str, Any]] = None,
+        data: Dict[str, Any] = None,
+    ) -> None:
+        super().__init__(status_code=status_code, detail=detail, headers=headers)
+        self.code = code
+        self.data = data
+
+
+class UnexpectedRelationshipState(Exception):
+    pass

common/injection.py

@@ -0,0 +1,9 @@
+from typing import Callable, Type, TypeVar
+from injector import Injector, singleton
+
+injector = Injector()
+T = TypeVar('T')
+
+def on(dependency_class: Type[T]) -> Callable[[], T]:
+  """Bridge between FastAPI injection and 'injector' DI framework."""
+  return lambda: injector.get(dependency_class)

docker-compose.yml

@@ -0,0 +1,22 @@
+services:
+  pgdatabase:
+    image: postgres:13
+    environment:
+      - POSTGRES_USER=user
+      - POSTGRES_PASSWORD=pass
+      - POSTGRES_DB=ecommerce
+    ports:
+      - '5432:5432'
+    volumes:
+      - db:/var/lib/postgresql/data
+  pgadmin:
+    image: dpage/pgadmin4
+    environment:
+      - [email protected]
+      - PGADMIN_DEFAULT_PASSWORD=admin
+    ports:
+      - '8080:80'
+
+volumes:
+  db:
+    driver: local

main.py

@@ -1,6 +1,7 @@
 import uvicorn
 from fastapi import APIRouter, FastAPI
 
+from authentication.crud import auth_router
 
 # Init FastAPI app
 app = FastAPI(
@@ -13,12 +14,14 @@
 # Routers
 api_router = APIRouter(prefix='/api')
 
+api_router.include_router(auth_router, tags=['auth'])
+
 app.include_router(api_router)
 
 # Startup event
-@app.on_event('startup')
-async def startup():
-  ...
+# @app.on_event('startup')
+# async def startup():
+#   ...
 
 # Shutdown event
 async def shutdown():

migrations/README

@@ -0,0 +1 @@
+Generic single-database configuration with an async dbapi.

migrations/env.py

@@ -0,0 +1,91 @@
+import asyncio
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+from sqlalchemy.engine import Connection
+from sqlalchemy.ext.asyncio import AsyncEngine
+from sqlmodel import SQLModel
+
+from alembic import context
+
+from authentication.models import User
+
+# this is the Alembic Config object, which provides
+# access to the values within the .ini file in use.
+config = context.config
+
+# Interpret the config file for Python logging.
+# This line sets up loggers basically.
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+target_metadata = SQLModel.metadata
+
+# other values from the config, defined by the needs of env.py,
+# can be acquired:
+# my_important_option = config.get_main_option("my_important_option")
+# ... etc.
+
+
+def run_migrations_offline() -> None:
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def do_run_migrations(connection: Connection) -> None:
+    context.configure(connection=connection, target_metadata=target_metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_migrations_online() -> None:
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = AsyncEngine(
+        engine_from_config(
+            config.get_section(config.config_ini_section),
+            prefix="sqlalchemy.",
+            poolclass=pool.NullPool,
+            future=True,
+        )
+    )
+
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await connectable.dispose()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    asyncio.run(run_migrations_online())