add initial alembic migrations setup

fabfile.py

@@ -17,7 +17,7 @@ def update():
 
 def migrate():
     with cd('/kerbos'):
-        run('python3 manage.py migrate')
+        run('python3 manage.py db upgrade')
 
 def reload_application():
     with cd('/kerbos'):

kerbos/config.py

@@ -1,27 +1,32 @@
 import os
 
 
-class Config(object):
+class DefaultConfig(object):
     DEBUG = False
     TESTING = False
     SECRET_KEY = 'thisisnotthesecretyouarelookingfor'
-    DEFAULT_DATABASE_URI = "postgresql://localhost/kerbos/"
+    DEFAULT_DATABASE_URI = "postgresql://postgres@localhost/kerbos"
     SQLALCHEMY_DATABASE_URI = os.environ.get('DATABASE_URL', default=DEFAULT_DATABASE_URI)
 
 
-class ProductionConfig(Config):
+class ProductionConfig(DefaultConfig):
     DEBUG = False
 
 
-class StagingConfig(Config):
+class StagingConfig(DefaultConfig):
     DEVELOPMENT = True
     DEBUG = True
 
 
-class DevelopmentConfig(Config):
+class DevelopmentConfig(DefaultConfig):
     DEVELOPMENT = True
     DEBUG = True
 
 
-class TestingConfig(Config):
+class TestingConfig(DefaultConfig):
     TESTING = True
+
+
+class CircleCIConfig(DefaultConfig):
+    TESTING = True
+    DEFAULT_DATABASE_URI = "postgresql://ubuntu@localhost/circle_test"

manage.py

@@ -1,6 +1,5 @@
 from flask_script import Manager
 from flask_migrate import Migrate, MigrateCommand
-import os
 
 from kerbos import get_app
 from kerbos.shared import APP as app, DB as db
@@ -15,12 +14,6 @@ def run():
     app = get_app(config='Development')
     get_app()
 
-@manager.command
-def migrate():
-    app = get_app(config='Production')
-    from kerbos.shared import DB as db
-    app.run()
-
 @manager.command
 def prod():
     app = get_app(config='Production')

migrations/README

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

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

migrations/env.py

@@ -0,0 +1,73 @@
+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
+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.
+
+    """
+    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,
+                      **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()
+

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"}