MagnetoDB/DeveloperGuide
Setting Up a Development Environment
This page describes how to setup a working Python development environment that can be used in developing MagnetoDB on Ubuntu. These instructions assume you’re already familiar with git. Following these instructions will allow you to run the MagnetoDB unit tests. If you want to be able to run MagnetoDB, you will also need to install Cassandra and Devstack.
Virtual environments
The easiest way to build a fully functional development environment is with DevStack. Create a machine (such as a VM or Vagrant box) running a distribution supported by DevStack and install DevStack there. For example, there is a Vagrant script for DevStack at https://github.com/jogo/DevstackUp.
NOTE: If you prefer not to use devstack, you can still check out source code on your local machine and develop from there.
Linux Systems
NOTE: This section is tested for MagnetoDB on Ubuntu (12.04-64) distribution. Feel free to add notes and change according to your experiences or operating system.
Install the prerequisite packages.
sudo apt-get install python-dev python-pip git-core
Getting the code
Grab the code from GitHub:
git clone https://github.com/stackforge/magnetodb.git
cd magnetodb
Running unit tests
The unit tests will run by default inside a virtualenv in the .venv directory. Run the unit tests by doing:
./run_tests.sh
The first time you run them, you will be asked if you want to create a virtual environment (hit “y”):
No virtual environment found...create one? (Y/n)
See Unit Tests for more details.
Manually installing and using the virtualenv
You can manually install the virtual environment instead of having run_tests.sh
do it for you:
python tools/install_venv.py
This will install all of the Python packages listed in the requirements.txt
file and also those listed in the test-requirements.txt
file into your virtualenv. There will also be some additional packages (pip, setuptools, greenlet) that are installed by the tools/install_venv.py
file into the virutalenv.
If all goes well, you should get a message something like this:
MagnetoDB development environment setup is complete.
To activate the MagnetoDB virtualenv for the extent of your current shell session you can run:
$ source .venv/bin/activate
Or, if you prefer, you can run commands in the virtualenv on a case by case basis by running:
$ tools/with_venv.sh <your command>
Remote development
Some modern IDE such as PyCharm (commercial/open source) support remote developing.
Some useful links:
Configuring Remote Interpreters via SSH
How PyCharm helps you with remote development
Configuring to work on a VM
Also, watch this video setting up dev enviroment for cases when MagnetoDB installed on the separate machines with Devstack:
MagnetoDB dev env configuration
Contributing Your Work
Once your work is complete you may wish to contribute it to the project. Refer to Improve MagnetoDB for information. MagnetoDB uses the Gerrit code review system. For information on how to submit your branch to Gerrit, see HowToContribute.
Unit Tests
MagnetoDB contains a suite of unit tests, in the /magnetodb/tests/unittests directory.
Any proposed code change will be automatically rejected by the OpenStack Jenkins server if the change causes unit test failures.
Preferred way to run the tests
The preferred way to run the unit tests is using tox
. See the unit testing section of the Testing wiki page for more information.
To run the Python 2.7 tests:
tox -e py27
To run the style tests:
tox -e pep8
You can request multiple tests, separated by commas:
tox -e py27,pep8
Older way to run the tests
Using tox
is preferred. It is also possible to run the unit tests using the run_tests.sh
script found at the top level of the project. The remainder of this document is focused on run_tests.sh
.
Run the unit tests by doing:
./run_tests.sh
This script is a wrapper around the testr testrunner and the flake8 checker.
Flags
The run_tests.sh
script supports several flags. You can view a list of flags by doing:
./run_tests.sh -h
This will show the following help information:
Usage: ./run_tests.sh [OPTION]... Run MagnetoDB's test suite(s) -V, --virtual-env Use virtualenv. Install automatically if not present. (Default is to run tests in local environment) -F, --force Force a clean re-build of the virtual environment. Useful when dependencies have been added. -f, --func Functional tests have been removed. -u, --unit Run unit tests (default when nothing specified) -p, --pep8 Run pep8 tests --all Run pep8 and unit tests -c, --coverage Generate coverage report -d, --debug Run tests with testtools instead of testr. This allows you to use the debugger. -h, --help Print this usage message
Because run_tests.sh
is a wrapper around testrepository, it also accepts the same flags as testr. See the testr user manual for details about these additional flags.
Running a subset of tests
Instead of running all tests, you can specify an individual directory, file, class, or method that contains test code.
To run the tests in the /magnetodb/tests/unittests/api/openstack/v1
directory:
./run_tests.sh v1
To run the tests in the /magnetodb/tests/unittests/api/openstack/v1/test_get_item.py
file:
./run_tests.sh test_boto
To run the tests in the GetItemTestCase
class in /magnetodb/tests/unittests/api/openstack/v1/test_get_item.py
:
./run_tests.sh test_get_item.GetItemTestCase
To run the GetItemTestCase.test_get_item test method in /magnetodb/tests/unittests/api/openstack/v1/test_get_item.py
:
./run_tests.sh test_get_item.GetItemTestCase.test_get_item
Virtualenv
By default, the tests use the Python packages installed inside a virtualenv. (This is equivalent to using the -V, --virtualenv
flag).
If you wish to recreate the virtualenv, call run_tests.sh
with the flag:
-f, --force
Recreating the virtualenv is useful if the package dependencies have changed since the virtualenv was last created. If the requirements.txt
or tools/install_venv.py
files have changed, it’s a good idea to recreate the virtualenv.