From 586f7192c9fe1917d41d1acfba28e331212c7ce0 Mon Sep 17 00:00:00 2001 From: Michael DeMarco Date: Thu, 4 Jan 2024 13:00:20 -0800 Subject: [PATCH] feat: add migrations --- .gitignore | 4 +- migrations/README | 1 + migrations/alembic.ini | 50 +++++++++++++++++ migrations/env.py | 113 ++++++++++++++++++++++++++++++++++++++ migrations/script.py.mako | 24 ++++++++ 5 files changed, 190 insertions(+), 2 deletions(-) create mode 100644 migrations/README create mode 100644 migrations/alembic.ini create mode 100644 migrations/env.py create mode 100644 migrations/script.py.mako diff --git a/.gitignore b/.gitignore index 552e55a..792fe70 100644 --- a/.gitignore +++ b/.gitignore @@ -1,7 +1,7 @@ ### Custom -migrations/** -!migrations/versions +# migrations/** +# !migrations/versions *.db *.rdb diff --git a/migrations/README b/migrations/README new file mode 100644 index 0000000..0e04844 --- /dev/null +++ b/migrations/README @@ -0,0 +1 @@ +Single-database configuration for Flask. diff --git a/migrations/alembic.ini b/migrations/alembic.ini new file mode 100644 index 0000000..ec9d45c --- /dev/null +++ b/migrations/alembic.ini @@ -0,0 +1,50 @@ +# A generic, single database configuration. + +[alembic] +# template used to generate migration files +# file_template = %%(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,flask_migrate + +[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 + +[logger_flask_migrate] +level = INFO +handlers = +qualname = flask_migrate + +[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 diff --git a/migrations/env.py b/migrations/env.py new file mode 100644 index 0000000..4c97092 --- /dev/null +++ b/migrations/env.py @@ -0,0 +1,113 @@ +import logging +from logging.config import fileConfig + +from flask import current_app + +from alembic import context + +# 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. +fileConfig(config.config_file_name) +logger = logging.getLogger('alembic.env') + + +def get_engine(): + try: + # this works with Flask-SQLAlchemy<3 and Alchemical + return current_app.extensions['migrate'].db.get_engine() + except (TypeError, AttributeError): + # this works with Flask-SQLAlchemy>=3 + return current_app.extensions['migrate'].db.engine + + +def get_engine_url(): + try: + return get_engine().url.render_as_string(hide_password=False).replace( + '%', '%%') + except AttributeError: + return str(get_engine().url).replace('%', '%%') + + +# 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', get_engine_url()) +target_db = current_app.extensions['migrate'].db + +# 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 get_metadata(): + if hasattr(target_db, 'metadatas'): + return target_db.metadatas[None] + return target_db.metadata + + +def run_migrations_offline(): + """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=get_metadata(), literal_binds=True + ) + + with context.begin_transaction(): + context.run_migrations() + + +def run_migrations_online(): + """Run migrations in 'online' mode. + + In this scenario we need to create an Engine + 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.') + + conf_args = current_app.extensions['migrate'].configure_args + if conf_args.get("process_revision_directives") is None: + conf_args["process_revision_directives"] = process_revision_directives + + connectable = get_engine() + + with connectable.connect() as connection: + context.configure( + connection=connection, + target_metadata=get_metadata(), + **conf_args + ) + + with context.begin_transaction(): + context.run_migrations() + + +if context.is_offline_mode(): + run_migrations_offline() +else: + run_migrations_online() diff --git a/migrations/script.py.mako b/migrations/script.py.mako new file mode 100644 index 0000000..2c01563 --- /dev/null +++ b/migrations/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(): + ${upgrades if upgrades else "pass"} + + +def downgrade(): + ${downgrades if downgrades else "pass"}