From 5d7b3b981d4c100382054bb00734e9911642961d Mon Sep 17 00:00:00 2001
From: Pierre Jaury <pierre@jaury.eu>
Date: Sat, 25 Jun 2016 12:57:47 +0200
Subject: [PATCH] Initialize the migration system

---
 admin/freeposte/__init__.py     | 21 +++++---
 admin/manage.py                 |  5 ++
 admin/migrations/alembic.ini    | 45 +++++++++++++++++
 admin/migrations/env.py         | 87 +++++++++++++++++++++++++++++++++
 admin/migrations/script.py.mako | 22 +++++++++
 admin/requirements.txt          |  6 ++-
 admin/run.py                    |  5 --
 7 files changed, 177 insertions(+), 14 deletions(-)
 create mode 100644 admin/manage.py
 create mode 100644 admin/migrations/alembic.ini
 create mode 100755 admin/migrations/env.py
 create mode 100755 admin/migrations/script.py.mako
 delete mode 100644 admin/run.py

diff --git a/admin/freeposte/__init__.py b/admin/freeposte/__init__.py
index 64d8eade..6938381c 100644
--- a/admin/freeposte/__init__.py
+++ b/admin/freeposte/__init__.py
@@ -1,14 +1,16 @@
-from flask import Flask
-from flask_sqlalchemy import SQLAlchemy
-from flask_bootstrap import Bootstrap
-from flask.ext import login as flask_login
+import flask
+import flask_sqlalchemy
+import flask_bootstrap
+import flask_login
+import flask_script
+import flask_migrate
 
 import os
 import docker
 
 
 # Create application
-app = Flask(__name__)
+app = flask.Flask(__name__)
 
 default_config = {
     'SQLALCHEMY_DATABASE_URI': 'sqlite:////data/freeposte.db',
@@ -23,11 +25,16 @@ for key, value in default_config.items():
     app.config[key] = os.environ.get(key, value)
 
 # Setup components
-Bootstrap(app)
-db = SQLAlchemy(app)
+flask_bootstrap.Bootstrap(app)
+db = flask_sqlalchemy.SQLAlchemy(app)
+migrate = flask_migrate.Migrate(app, db)
 login_manager = flask_login.LoginManager()
 login_manager.init_app(app)
 
+# Manager commnad
+manager = flask_script.Manager(app)
+manager.add_command('db', flask_migrate.MigrateCommand)
+
 # Connect to the Docker socket
 dockercli = docker.Client(base_url=app.config['DOCKER_SOCKET'])
 
diff --git a/admin/manage.py b/admin/manage.py
new file mode 100644
index 00000000..fd04185c
--- /dev/null
+++ b/admin/manage.py
@@ -0,0 +1,5 @@
+from freeposte import manager
+
+
+if __name__ == "__main__":
+    manager.run()
diff --git a/admin/migrations/alembic.ini b/admin/migrations/alembic.ini
new file mode 100644
index 00000000..f8ed4801
--- /dev/null
+++ b/admin/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
diff --git a/admin/migrations/env.py b/admin/migrations/env.py
new file mode 100755
index 00000000..45938160
--- /dev/null
+++ b/admin/migrations/env.py
@@ -0,0 +1,87 @@
+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()
diff --git a/admin/migrations/script.py.mako b/admin/migrations/script.py.mako
new file mode 100755
index 00000000..95702017
--- /dev/null
+++ b/admin/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/admin/requirements.txt b/admin/requirements.txt
index 9069ffa4..218c5887 100644
--- a/admin/requirements.txt
+++ b/admin/requirements.txt
@@ -1,9 +1,11 @@
 Flask
 Flask-Login
 Flask-SQLAlchemy
-gunicorn
+Flask-bootstrap
+Flask-migrate
+Flask-script
 flask_wtf
 WTForms-Components
-Flask-bootstrap
 passlib
+gunicorn
 docker-py
diff --git a/admin/run.py b/admin/run.py
deleted file mode 100644
index 9b9768eb..00000000
--- a/admin/run.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from freeposte import app, db
-
-
-if __name__ == '__main__':
-    app.run(debug=True)