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-rw-r--r--mediagoblin/db/migrations/README57
-rw-r--r--mediagoblin/db/migrations/env.py71
-rw-r--r--mediagoblin/db/migrations/script.py.mako22
-rw-r--r--mediagoblin/db/migrations/versions/.gitkeep0
4 files changed, 150 insertions, 0 deletions
diff --git a/mediagoblin/db/migrations/README b/mediagoblin/db/migrations/README
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+++ b/mediagoblin/db/migrations/README
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+Migration Guide
+---------------
+
+Alembic comes with a CLI called ``alembic``.
+
+Create a Migration
+^^^^^^^^^^^^^^^^^^
+
+Lets create our first migration::
+
+ $ alembic revision -m "add favourite_band field"
+ Generating
+ /your/gmg/path/mediagoblin/db/migrations/versions/1e3793de36a_add_favourite_band_field.py ... done
+
+By default, migration files have two methods: ``upgrade`` and ``downgrade``.
+Alembic will invoke these methods to apply the migrations to your current
+database.
+
+Now, we need to edit our newly created migration file
+``1e3793de36a_add_favourite_band_field.py`` to add a new column ``favourite_band``
+to ``core__users`` table::
+
+ def upgrade():
+ op.add_column('core__users', sa.Column('favourite_band', sa.Unicode(100)))
+
+
+ def downgrade():
+ op.drop_column('core__users', 'favourite_band')
+
+.. note::
+
+ Alembic can also generate `automatic migrations <http://alembic.readthedocs.org/en/latest/tutorial.html#auto-generating-migrations>`__.
+
+Then we can run ``gmg dbupdate`` to apply the new migration::
+
+ $ gmg dbupdate
+ INFO [alembic.migration] Context impl SQLiteImpl.
+ INFO [alembic.migration] Will assume non-transactional DDL.
+ INFO [alembic.migration] Running upgrade None -> 1e3793de36a, add favourite band field
+
+If you want to revert that migration, simply run::
+
+ $ alembic downgrade -1
+
+.. warning::
+
+ Currently, Alembic cannot do ``DROP COLUMN``, ``ALTER COLUMN`` etc.
+ operations in SQLite. Please see https://bitbucket.org/zzzeek/alembic/issue/21/column-renames-not-supported-on-sqlite
+ for detailed information.
+
+Glossary
+^^^^^^^^
+
+* ``alembic.ini``: The Alembic configuration file. The ``alembic`` CLI will
+ look that file everytime it invaked.
+* ``mediagoblin/db/migrations/versions/``: Alembic will add new migration files
+ to this directory.
diff --git a/mediagoblin/db/migrations/env.py b/mediagoblin/db/migrations/env.py
new file mode 100644
index 00000000..712b6164
--- /dev/null
+++ b/mediagoblin/db/migrations/env.py
@@ -0,0 +1,71 @@
+from __future__ import with_statement
+from alembic import context
+from sqlalchemy import engine_from_config, pool
+from logging.config import fileConfig
+
+# 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)
+
+# add your model's MetaData object here
+# for 'autogenerate' support
+# from myapp import mymodel
+# target_metadata = mymodel.Base.metadata
+target_metadata = None
+
+# 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, target_metadata=target_metadata)
+
+ 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.
+
+ """
+ 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
+ )
+
+ try:
+ with context.begin_transaction():
+ context.run_migrations()
+ finally:
+ connection.close()
+
+if context.is_offline_mode():
+ run_migrations_offline()
+else:
+ run_migrations_online()
+
diff --git a/mediagoblin/db/migrations/script.py.mako b/mediagoblin/db/migrations/script.py.mako
new file mode 100644
index 00000000..95702017
--- /dev/null
+++ b/mediagoblin/db/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"}
diff --git a/mediagoblin/db/migrations/versions/.gitkeep b/mediagoblin/db/migrations/versions/.gitkeep
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/mediagoblin/db/migrations/versions/.gitkeep