Handle migrations through alembic/flask-Migrations

Auto-initialization now applies migrations instead of using db. create_all()

fix #83

budget/migrations/README

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

budget/migrations/alembic.ini

@@ -0,0 +1,45 @@
+# 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
+
+[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

budget/migrations/env.py

@@ -0,0 +1,85 @@
+from __future__ import with_statement
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+from logging.config import fileConfig
+import logging
+
+# 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')
+
+# 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'))
+target_metadata = current_app.extensions['migrate'].db.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():
+    """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)
+
+    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.readthedocs.org/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.')
+
+    engine = engine_from_config(config.get_section(config.config_ini_section),
+                                prefix='sqlalchemy.',
+                                poolclass=pool.NullPool)
+
+    connection = engine.connect()
+    context.configure(connection=connection,
+                      target_metadata=target_metadata,
+                      process_revision_directives=process_revision_directives,
+                      **current_app.extensions['migrate'].configure_args)
+
+    try:
+        with context.begin_transaction():
+            context.run_migrations()
+    finally:
+        connection.close()
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

budget/migrations/script.py.mako

@@ -0,0 +1,22 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision}
+Create Date: ${create_date}
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

budget/migrations/versions/b9a10d5d63ce_.py

@@ -0,0 +1,68 @@
+"""Initial migration
+
+Revision ID: b9a10d5d63ce
+Revises: None
+Create Date: 2016-05-21 23:21:21.605076
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'b9a10d5d63ce'
+down_revision = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('project',
+    sa.Column('id', sa.String(length=64), nullable=False),
+    sa.Column('name', sa.UnicodeText(), nullable=True),
+    sa.Column('password', sa.String(length=128), nullable=True),
+    sa.Column('contact_email', sa.String(length=128), nullable=True),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_table('archive',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('project_id', sa.String(length=64), nullable=True),
+    sa.Column('name', sa.UnicodeText(), nullable=True),
+    sa.ForeignKeyConstraint(['project_id'], ['project.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_table('person',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('project_id', sa.String(length=64), nullable=True),
+    sa.Column('name', sa.UnicodeText(), nullable=True),
+    sa.Column('activated', sa.Boolean(), nullable=True),
+    sa.ForeignKeyConstraint(['project_id'], ['project.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_table('bill',
+    sa.Column('id', sa.Integer(), nullable=False),
+    sa.Column('payer_id', sa.Integer(), nullable=True),
+    sa.Column('amount', sa.Float(), nullable=True),
+    sa.Column('date', sa.Date(), nullable=True),
+    sa.Column('what', sa.UnicodeText(), nullable=True),
+    sa.Column('archive', sa.Integer(), nullable=True),
+    sa.ForeignKeyConstraint(['archive'], ['archive.id'], ),
+    sa.ForeignKeyConstraint(['payer_id'], ['person.id'], ),
+    sa.PrimaryKeyConstraint('id')
+    )
+    op.create_table('billowers',
+    sa.Column('bill_id', sa.Integer(), nullable=True),
+    sa.Column('person_id', sa.Integer(), nullable=True),
+    sa.ForeignKeyConstraint(['bill_id'], ['bill.id'], ),
+    sa.ForeignKeyConstraint(['person_id'], ['person.id'], )
+    )
+    ### end Alembic commands ###
+
+
+def downgrade():
+    ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('billowers')
+    op.drop_table('bill')
+    op.drop_table('person')
+    op.drop_table('archive')
+    op.drop_table('project')
+    ### end Alembic commands ###

budget/requirements.txt

@@ -2,6 +2,7 @@ flask>=0.9
 flask-wtf==0.8
 flask-sqlalchemy
 flask-mail>=0.8
+Flask-Migrate==1.8.0
 flask-babel
 flask-rest
 jinja2==2.6

budget/run.py

@@ -3,6 +3,7 @@ import warnings
 
 from flask import Flask, g, request, session
 from flask.ext.babel import Babel
+from flask.ext.migrate import Migrate, upgrade
 from raven.contrib.flask import Sentry
 
 from web import main, db, mail
@@ -39,7 +40,13 @@ app.register_blueprint(api)
 # db
 db.init_app(app)
 db.app = app
-db.create_all()
+
+# db migrations
+migrate = Migrate(app, db)
+
+# auto-execute migrations on runtime
+with app.app_context():
+    upgrade()
 
 # mail
 mail.init_app(app)