ironic-dbsync¶
The ironic-dbsync utility is used to create the database schema tables that the ironic services will use for storage. It can also be used to upgrade existing database tables when migrating between different versions of ironic.
The Alembic library is used to perform the database migrations.
Options¶
This is a partial list of the most useful options. To see the full list, run the following:
ironic-dbsync --help
-
-h,--help¶ Show help message and exit.
-
--config-dir<DIR>¶ Path to a config directory with configuration files.
-
--config-file<PATH>¶ Path to a configuration file to use.
-
-d,--debug¶ Print debugging output.
-
--version¶ Show the program’s version number and exit.
Usage¶
Options for the various commands for
ironic-dbsync are listed when the -h or --help
option is used after the command.
For example:
ironic-dbsync create_schema --help
Information about the database is read from the ironic configuration file
used by the API server and conductor services. This file must be specified
with the --config-file option:
ironic-dbsync --config-file /path/to/ironic.conf create_schema
The configuration file defines the database backend to use with the connection database option:
[database]
connection=mysql+pymysql://root@localhost/ironic
If no configuration file is specified with the --config-file option,
ironic-dbsync assumes an SQLite database.
Command Options¶
ironic-dbsync is given a command that tells the utility what actions to perform. These commands can take arguments. Several commands are available:
create_schema¶
-
-h,--help¶ Show help for create_schema and exit.
This command will create database tables based on the most current version. It assumes that there are no existing tables.
An example of creating database tables with the most recent version:
ironic-dbsync --config-file=/etc/ironic/ironic.conf create_schema
online_data_migrations¶
-
-h,--help¶ Show help for online_data_migrations and exit.
-
--max-count<NUMBER>¶ The maximum number of objects (a positive value) to migrate. Optional. If not specified, all the objects will be migrated (in batches of 50 to avoid locking the database for long periods of time).
-
--option<MIGRATION.KEY=VALUE>¶ If a migration accepts additional parameters, they can be passed via this argument. It can be specified several times.
This command will migrate objects in the database to their most recent versions. This command must be successfully run (return code 0) before upgrading to a future release.
It returns:
1 (not completed) if there are still pending objects to be migrated. Before upgrading to a newer release, this command must be run until 0 is returned.
0 (success) after migrations are finished or there are no data to migrate
127 (error) if max-count is not a positive value or an option is invalid
2 (error) if the database is not compatible with this release. This command needs to be run using the previous release of ironic, before upgrading and running it with this release.
revision¶
-
-h,--help¶ Show help for revision and exit.
-
-m<MESSAGE>,--message<MESSAGE>¶ The message to use with the revision file.
-
--autogenerate¶ Compares table metadata in the application with the status of the database and generates migrations based on this comparison.
This command will create a new revision file. You can use the
--message option to comment the revision.
This is really only useful for ironic developers making changes that require database changes. This revision file is used during database migration and will specify the changes that need to be made to the database tables. Further discussion is beyond the scope of this document.
stamp¶
-
-h,--help¶ Show help for stamp and exit.
-
--revision<REVISION>¶ The revision number.
This command will ‘stamp’ the revision table with the version specified with
the --revision option. It will not run any migrations.
upgrade¶
-
-h,--help¶ Show help for upgrade and exit.
-
--revision<REVISION>¶ The revision number to upgrade to.
This command will upgrade existing database tables to the most recent version,
or to the version specified with the --revision option.
Before this upgrade is invoked, the command
ironic-dbsync online_data_migrations must have been successfully run
using the previous version of ironic (if you are doing an upgrade as opposed to
a new installation of ironic). If it wasn’t run, the database will not be
compatible with this recent version of ironic, and this command will return
2 (error).
If there are no existing tables, then new tables are created, beginning with the oldest known version, and successively upgraded using all of the database migration files, until they are at the specified version. Note that this behavior is different from the create_schema command that creates the tables based on the most recent version.
An example of upgrading to the most recent table versions:
ironic-dbsync --config-file=/etc/ironic/ironic.conf upgrade
Note
This command is the default if no command is given to ironic-dbsync.
Warning
The upgrade command is not compatible with SQLite databases since it uses ALTER TABLE commands to upgrade the database tables. SQLite supports only a limited subset of ALTER TABLE.
