Added support for automatic database migrations.

Added Alembic environment and `run_db_migrations` logic to the entities
engine so database schema changes can be processed as soon as the
application is started.
This commit is contained in:
Fabio Manganiello 2023-04-29 11:32:31 +02:00
parent ff9b76477d
commit 78cee5d9b0
Signed by untrusted user: blacklight
GPG key ID: D90FBA7F76362774
7 changed files with 286 additions and 5 deletions

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@ -1,12 +1,16 @@
import logging
import inspect
import json
import os
import pathlib
import subprocess
import sys
import types
from datetime import datetime
import pkgutil
from typing import Callable, Dict, Final, Optional, Set, Type, Tuple, Any
import pkgutil
from dateutil.tz import tzutc
from sqlalchemy import (
Boolean,
@ -23,6 +27,7 @@ from sqlalchemy import (
from sqlalchemy.orm import ColumnProperty, backref, relationship
from sqlalchemy.orm.exc import ObjectDeletedError
import platypush
from platypush.common.db import Base
from platypush.message import JSONAble, Message
@ -170,7 +175,10 @@ if 'entity' not in Base.metadata:
return normalized_name
except ObjectDeletedError as e:
logger.warning(
f'Could not access column "{col.key}" for entity ID "{self.id}": {e}'
'Could not access column "%s" for entity ID "{%s}": {%s}',
col.key,
self.id,
e,
)
return None
@ -267,9 +275,9 @@ def _discover_entity_types():
isinstance(e, (ImportError, ModuleNotFoundError))
and modname[len(__package__) + 1 :] in _import_error_ignored_modules
):
logger.debug(f'Could not import module {modname}')
logger.debug('Could not import module %s', modname)
else:
logger.warning(f'Could not import module {modname}')
logger.warning('Could not import module %s', modname)
logger.exception(e)
continue
@ -292,7 +300,31 @@ def init_entities_db():
"""
from platypush.context import get_plugin
run_db_migrations()
_discover_entity_types()
db = get_plugin('db')
assert db
db.create_all(db.get_engine(), Base)
def run_db_migrations():
"""
Run the database migrations upon engine initialization.
"""
logger.info('Running database migrations')
alembic_ini = os.path.join(
os.path.dirname(inspect.getabsfile(platypush)), 'migrations', 'alembic.ini'
)
subprocess.run(
[
sys.executable,
'-m',
'alembic',
'-c',
alembic_ini,
'upgrade',
'head',
],
check=True,
)

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@ -0,0 +1,106 @@
# A generic, single database configuration.
[alembic]
# path to migration scripts
script_location = %(here)s/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/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
# Use os.pathsep. Default configuration used for new projects.
version_path_separator = os
# the output encoding used when revision files
# are written from script.py.mako
# output_encoding = utf-8
sqlalchemy.url = %(DB_ENGINE)s
[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

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@ -0,0 +1,92 @@
from logging.config import fileConfig
from sqlalchemy import engine_from_config
from sqlalchemy import pool
from alembic import context
from platypush.config import Config
from platypush.common.db 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
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()
def set_db_engine():
db_conf = Config.get('db')
assert db_conf, 'Could not retrieve the database configuration'
engine = db_conf['engine']
assert engine, 'No database engine configured'
config = context.config
section = config.config_ini_section
config.set_section_option(section, 'DB_ENGINE', engine)
set_db_engine()
if context.is_offline_mode():
run_migrations_offline()
else:
run_migrations_online()

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@ -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"}

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@ -0,0 +1,22 @@
"""Base alembic version
Revision ID: d030953a871d
Revises:
Create Date: 2023-04-28 22:32:49.460118
"""
# revision identifiers, used by Alembic.
revision = 'd030953a871d'
down_revision = None
branch_labels = None
depends_on = None
def upgrade() -> None:
pass
def downgrade() -> None:
pass

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@ -13,7 +13,8 @@ python-dateutil
tz
frozendict
requests
sqlalchemy<2.0.0
sqlalchemy
alembic
bcrypt
rsa
zeroconf>=0.27.0

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@ -38,6 +38,9 @@ setup(
url="https://platypush.tech",
packages=find_packages(),
include_package_data=True,
package_data={
'platypush': ['alembic.ini', 'alembic/*', 'alembic/**/*'],
},
entry_points={
'console_scripts': [
'platypush=platypush:main',
@ -58,6 +61,7 @@ setup(
'requests',
'croniter',
'sqlalchemy',
'alembic',
'websockets',
'websocket-client',
'wheel',