Adding alembic and sql support

.gitignore

@@ -137,3 +137,6 @@ dmypy.json
 
 # Cython debug symbols
 cython_debug/
+
+# sqlite
+*.sqlite3

.pylintrc

@@ -0,0 +1,2 @@
+[MASTER]
+ignore-paths=^alembic\\.*$|^alembic/.*$

alembic.ini

@@ -0,0 +1,105 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = alembic
+
+# 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
+# see https://alembic.sqlalchemy.org/en/latest/tutorial.html#editing-the-ini-file
+# for all available tokens
+# 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 alembic/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:alembic/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 = driver://user:pass@localhost/dbname
+
+
+[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

alembic/README

@@ -0,0 +1 @@
+Generic single-database configuration.

alembic/env.py

@@ -0,0 +1,85 @@
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+
+from project import create_app
+from project.config import settings
+from project.database import Base
+
+# 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
+config.set_main_option("sqlalchemy.url", str(settings.DATABASE_URL))
+
+# Used create_app to create a new fastapi_app instance to ensure the relevant models are loaded.
+fastapi_app = create_app()
+
+target_metadata = Base.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 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 = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

alembic/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

alembic/versions/4e1bcbead27f_.py

@@ -0,0 +1,28 @@
+"""empty message
+
+Revision ID: 4e1bcbead27f
+Revises:
+Create Date: 2022-09-21 20:11:34.057323
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "4e1bcbead27f"
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    pass
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    pass
+    # ### end Alembic commands ###

alembic/versions/b03fcdc9b301_.py

@@ -0,0 +1,36 @@
+"""empty message
+
+Revision ID: b03fcdc9b301
+Revises: 4e1bcbead27f
+Create Date: 2022-09-23 15:50:30.792964
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "b03fcdc9b301"
+down_revision = "4e1bcbead27f"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table(
+        "users",
+        sa.Column("id", sa.BigInteger(), autoincrement=True, nullable=False),
+        sa.Column("username", sa.String(length=128), nullable=False),
+        sa.Column("email", sa.String(length=128), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("email"),
+        sa.UniqueConstraint("username"),
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table("users")
+    # ### end Alembic commands ###

main.py

@@ -1,22 +1,4 @@
-from celery import Celery
-from fastapi import FastAPI
+from project import create_app
 
-app = FastAPI()
-
-
-celery = Celery(
-    __name__, broker="redis://127.0.0.1:6379/0", backend="redis://127.0.0.1:6379/0"
-)
-
-
-@app.get("/")
-async def root():
-    return {"message": "Hello World"}
-
-
-@celery.task
-def divide(x, y):
-    import time
-
-    time.sleep(5)
-    return x / y
+app = create_app()
+celery = app.celery_app

project/__init__.py

@@ -0,0 +1,18 @@
+from fastapi import FastAPI
+
+from project.celery_utils import create_celery
+
+
+def create_app() -> FastAPI:
+    app = FastAPI()
+    app.celery_app = create_celery()
+
+    from .users import users_router
+
+    app.include_router(users_router)
+
+    @app.get("/")
+    async def root():
+        return {"message": "Hello World"}
+
+    return app

project/celery_utils.py

@@ -0,0 +1,11 @@
+from celery import current_app as celery_current_app
+
+from project.config import settings
+
+
+def create_celery():
+    """Clerey factory function."""
+    celery_app = celery_current_app
+    celery_app.config_from_object(settings, namespace="CELERY")
+
+    return celery_app

project/config.py

@@ -0,0 +1,47 @@
+import os
+import pathlib
+from functools import lru_cache
+
+
+class BaseConfig:
+    BASE_DIR: pathlib.Path = pathlib.Path(__file__).parent.parent
+
+    DATABASE_URL: str = os.environ.get(
+        "DATABASE_URL", f"sqlite:///{BASE_DIR}/db.sqlite3"
+    )
+    DATABASE_CONNECT_DICT: dict = {}
+
+    CELERY_BROKER_URL: str = os.environ.get(
+        "CELERY_BROKER_URL", "redis://127.0.0.1:6379/0"
+    )
+    CELERY_RESULT_BACKEND: str = os.environ.get(
+        "CELERY_RESULT_BACKEND", "redis://127.0.0.1:6379/0"
+    )
+
+
+class DevelopmentConfig(BaseConfig):
+    pass
+
+
+class ProductionConfig(BaseConfig):
+    pass
+
+
+class TestingConfig(BaseConfig):
+    pass
+
+
+@lru_cache()
+def get_settings():
+    config_cls_dict = {
+        "development": DevelopmentConfig,
+        "production": ProductionConfig,
+        "testing": TestingConfig,
+    }
+
+    config_name = os.environ.get("FASTAPI_CONFIG", "development")
+    config_cls = config_cls_dict[config_name]
+    return config_cls()
+
+
+settings = get_settings()

project/database.py

@@ -0,0 +1,13 @@
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+
+from project.config import settings
+
+# https://fastapi.tiangolo.com/tutorial/sql-databases/#create-the-sqlalchemy-engine
+engine = create_engine(
+    settings.DATABASE_URL, connect_args=settings.DATABASE_CONNECT_DICT
+)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()

project/users/__init__.py

@@ -0,0 +1,9 @@
+from fastapi import APIRouter
+
+from project.celery_utils import create_celery
+
+users_router = APIRouter(
+    prefix="/users",
+)
+
+from . import models, tasks  # noqa

project/users/models.py

@@ -0,0 +1,18 @@
+from sqlalchemy import BigInteger, Column, String
+
+from project.database import Base
+
+
+class User(Base):
+
+    __tablename__ = "users"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    username = Column(String(128), unique=True, nullable=False)
+    email = Column(String(128), unique=True, nullable=False)
+
+    def __init__(
+        self, username, email, *args, **kwargs  # pylint: disable=unused-argument
+    ) -> None:
+        self.username = username
+        self.email = email

project/users/tasks.py

@@ -0,0 +1,15 @@
+"""
+Many resources on the web recommend using celery.task. This might cause circular imports since you'll have to import the Celery instance.
+We used shared_task to make our code reusable, which, again, requires current_app in create_celery instead of creating a new Celery instance.
+Now, we can copy this file anywhere in the app and it will work as expected.
+"""
+
+from celery import shared_task
+
+
+@shared_task
+def divide(x, y):
+    import time
+
+    time.sleep(5)
+    return x / y

requirements.in

@@ -1,5 +1,7 @@
+alembic==1.8.1
 celery==5.2.7
 fastapi==0.79.0
 flower==1.2.0
 redis==4.3.4
+SQLAlchemy==1.4.40
 uvicorn[standard]==0.18.2

requirements.txt

@@ -4,6 +4,8 @@
 #
 #    pip-compile requirements.in
 #
+alembic==1.8.1
+    # via -r requirements.in
 amqp==5.1.1
     # via kombu
 anyio==3.6.1
@@ -37,6 +39,8 @@ fastapi==0.79.0
     # via -r requirements.in
 flower==1.2.0
     # via -r requirements.in
+greenlet==1.1.3
+    # via sqlalchemy
 h11==0.13.0
     # via uvicorn
 httptools==0.5.0
@@ -45,8 +49,16 @@ humanize==4.4.0
     # via flower
 idna==3.4
     # via anyio
+importlib-metadata==4.12.0
+    # via alembic
+importlib-resources==5.9.0
+    # via alembic
 kombu==5.2.4
     # via celery
+mako==1.2.2
+    # via alembic
+markupsafe==2.1.1
+    # via mako
 packaging==21.3
     # via redis
 prometheus-client==0.14.1
@@ -71,6 +83,10 @@ six==1.16.0
     # via click-repl
 sniffio==1.3.0
     # via anyio
+sqlalchemy==1.4.40
+    # via
+    #   -r requirements.in
+    #   alembic
 starlette==0.19.1
     # via fastapi
 tornado==6.2
@@ -96,3 +112,7 @@ websockets==10.3
     # via uvicorn
 wrapt==1.14.1
     # via deprecated
+zipp==3.8.1
+    # via
+    #   importlib-metadata
+    #   importlib-resources

tasks.py

@@ -38,3 +38,30 @@ def stop_redis(c):
     """Stops the Redis integration environent."""
     print("Stopping Redis")
     c.run("docker compose -f docker-compose-redis.yml down")
+
+
+@task
+def create_migration(c):
+    """Creates a sqlalchemy migration."""
+    c.run("alembic revision --autogenerate")
+
+
+@task
+def apply_migration(c, revision="head"):
+    """Applies an Alembic migration."""
+    c.run(f"alembic upgrade {revision}")
+
+
+@task(help={"username": "Username of the application", "email": "User's email"})
+def add_user(username="", email=""):
+    "Adds a dummy user to the application Database"
+    if not username or email:
+        raise ValueError("You must provide a username and email")
+    from project.database import SessionLocal
+    from project.users.models import User
+
+    session = SessionLocal()
+    user = User(username=username, email=email)
+    session.add(user)
+    session.commit()
+    session.close()