At the command line:
$ pip install oslo.db
You will also need to install at least one SQL backend:
$ pip install psycopg2
Or:
$ pip install PyMySQL
Or:
$ pip install pysqlite
If you are using PostgreSQL make sure to install the PostgreSQL client development package for your distro. On Ubuntu this is done as follows:
$ sudo apt-get install libpq-dev
$ pip install psycopg2
The installation of psycopg2 will fail if libpq-dev is not installed first. Note that even in a virtual environment the libpq-dev will be installed system wide.
PyMySQL is a default MySQL DB API driver for oslo.db, as well as for the whole OpenStack. But you still can use MySQL-python as an alternative DB API driver. For MySQL-python you must install the MySQL client development package for your distro. On Ubuntu this is done as follows:
$ sudo apt-get install libmysqlclient-dev
$ pip install MySQL-python
The installation of MySQL-python will fail if libmysqlclient-dev is not installed first. Note that even in a virtual environment the MySQL package will be installed system wide.