Use alembic instead of flask migrate which depends on flask-sqlalchemy

CONTRIBUTING.md

@@ -76,7 +76,7 @@ docker run -e POSTGRES_PASSWORD=mypassword -e POSTGRES_USER=myuser -e POSTGRES_D
 To run the server:
 
 ```
-flask db upgrade && flask dummy-data && python3 server.py
+alembic upgrade head && flask dummy-data && python3 server.py
 ```
 
 then open http://localhost:7777, you should be able to login with `john@wick.com / password` account.

alembic.ini

@@ -0,0 +1,83 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration files
+file_template = %%(year)d_%%(month).2d%%(day).2d%%(hour).2d_%%(rev)s_%%(slug)s
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# 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
+# version_locations = %(here)s/bar %(here)s/bat alembic/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+
+[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
+
+# 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

migrations/README

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

migrations/alembic.ini

@@ -1,45 +0,0 @@
-# A generic, single database configuration.
-
-[alembic]
-# template used to generate migration files
-file_template = %%(year)d_%%(month).2d%%(day).2d%%(hour).2d_%%(rev)s_%%(slug)s
-
-# set to 'true' to run the environment during
-# the 'revision' command, regardless of autogenerate
-# revision_environment = false
-
-
-# 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

migrations/env.py

@@ -1,6 +1,3 @@
-from __future__ import with_statement
-
-import logging
 from logging.config import fileConfig
 
 from sqlalchemy import engine_from_config
@@ -15,23 +12,28 @@ config = context.config
 # Interpret the config file for Python logging.
 # This line sets up loggers basically.
 fileConfig(config.config_file_name)
-logger = logging.getLogger('alembic.env')
 
 # add your model's MetaData object here
 # for 'autogenerate' support
 # from myapp import mymodel
 # target_metadata = mymodel.Base.metadata
-from flask import current_app
-config.set_main_option(
-    'sqlalchemy.url', current_app.config.get(
-        'SQLALCHEMY_DATABASE_URI').replace('%', '%%'))
-target_metadata = current_app.extensions['migrate'].db.metadata
+import sys
+
+# hack to be able to import Base
+# cf https://stackoverflow.com/a/58891735/1428034
+sys.path = ['', '..'] + sys.path[1:]
+
+from app.models import Base
+from app.config import DB_URI
+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.
 
+config.set_main_option('sqlalchemy.url', DB_URI)
+
 
 def run_migrations_offline():
     """Run migrations in 'offline' mode.
@@ -47,7 +49,10 @@ def run_migrations_offline():
     """
     url = config.get_main_option("sqlalchemy.url")
     context.configure(
-        url=url, target_metadata=target_metadata, literal_binds=True
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
     )
 
     with context.begin_transaction():
@@ -61,29 +66,15 @@ def run_migrations_online():
     and associate a connection with the context.
 
     """
-
-    # this callback is used to prevent an auto-migration from being generated
-    # when there are no changes to the schema
-    # reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
-    def process_revision_directives(context, revision, directives):
-        if getattr(config.cmd_opts, 'autogenerate', False):
-            script = directives[0]
-            if script.upgrade_ops.is_empty():
-                directives[:] = []
-                logger.info('No changes in schema detected.')
-
     connectable = engine_from_config(
         config.get_section(config.config_ini_section),
-        prefix='sqlalchemy.',
+        prefix="sqlalchemy.",
         poolclass=pool.NullPool,
     )
 
     with connectable.connect() as connection:
         context.configure(
-            connection=connection,
-            target_metadata=target_metadata,
-            process_revision_directives=process_revision_directives,
-            **current_app.extensions['migrate'].configure_args
+            connection=connection, target_metadata=target_metadata
         )
 
         with context.begin_transaction():

scripts/new-migration.sh

@@ -6,11 +6,14 @@
 docker rm -f sl-db
 docker run -p 25432:5432 --name sl-db -e POSTGRES_PASSWORD=postgres -e POSTGRES_DB=sl -d postgres:13
 
-# run run `flask db upgrade` to upgrade the DB to the latest stage and
-env DB_URI=postgresql://postgres:postgres@127.0.0.1:25432/sl poetry run flask db upgrade
+# sleep a little bit for the db to be ready
+sleep 3
 
-# finally `flask db migrate` to generate the migration script.
-env DB_URI=postgresql://postgres:postgres@127.0.0.1:25432/sl poetry run flask db migrate
+# upgrade the DB to the latest stage and
+env DB_URI=postgresql://postgres:postgres@127.0.0.1:25432/sl poetry run alembic upgrade head
+
+# generate the migration script.
+env DB_URI=postgresql://postgres:postgres@127.0.0.1:25432/sl poetry run alembic revision --autogenerate
 
 # remove the db
 docker rm -f sl-db