442b597929
cdr, config and voicemail are all separate alembic trees. Because alembic's default is to use a table named 'alembic_version' to store the current tree revision, the 3 trees can't exist in the same schema without stepping on each other. Now each tree uses 'alembic_version_<tree_name>' as the version table. Each tree's env.py script now first checks for 'alembic_version'. If it finds it AND its revision is in the tree's history, the script renames it to 'alembic_version_<tree_name>'. Regardless, the script then continues with the migration using 'alembic_version_<tree_name>' and creates that table if it's not found. The result is that if an existing 'alembic_version' table was found but it didn't belong to this tree, it's left alone and 'alembic_version_<tree_name>' is used or created. WARNING: If multiple trees are using the same schema, they MUST NOT CRU or D any objects with names that might exist in the other trees. An example would be 'yesno_values' type. If two trees perform operations on it, one tree could pull it out from under the other. Thankfully we currently don't share any names among cdr, config and voicemail. NOTE: Since the env.py scripts in each tree were identical, a common env.py has been placed in the ast-db-manage directory and a symlink to it has been placed in each tree directory. ASTERISK-24311 #close Reported-by: Dafi Ni Change-Id: I4d593f000350deb5d21a14fa1e9bc3896844d898
Asterisk Database Manager
Asterisk includes optional database integration for a variety of features. The purpose of this effort is to assist in managing the database schema for Asterisk database integration.
This is implemented as a set of repositories that contain database schema migrations, using Alembic. The existing repositories include:
config- Tables used for Asterisk realtime configurationvoicemail- Tables used forODBC_STOARGEof voicemail messages
Alembic uses SQLAlchemy, which has support for many databases.
IMPORTANT NOTE: This is brand new and the initial migrations are still subject to change. Only use this for testing purposes for now.
Example Usage
First, create an ini file that contains database connection details. For help with connection string details, see the SQLAlchemy docs.
$ cp config.ini.sample config.ini
... edit config.ini and change sqlalchemy.url ...
Next, bring the database up to date with the current schema.
$ alembic -c config.ini upgrade head
In the future, as additional database migrations are added, you can run alembic again to migrate the existing tables to the latest schema.
$ alembic -c config.ini upgrade head
The migrations support both upgrading and downgrading. You could go all the way back to where you started with no tables by downgrading back to the base revision.
$ alembic -c config.ini downgrade base
base and head are special revisions. You can refer to specific revisions
to upgrade or downgrade to, as well.
$ alembic -c config.ini upgrade 4da0c5f79a9c
Offline Mode
If you would like to just generate the SQL statements that would have been executed, you can use alembic's offline mode.
$ alembic -c config.ini upgrade head --sql
Adding Database Migrations
The best way to learn about how to add additional database migrations is to refer to the Alembic documentation.