Creating Wagons

Wagon is a tool for packaging sets of Python wheels.

Requirements

• Wagon installed in virtualenv(see wagon installation section).
• Studio Conductor in your local Python path.
• A zip archive of the plugin package, such as https://github.com/cloudify-cosmo/cloudify-openstack-plugin/archive/2.2.0.zip.
• A constraints.txt with any specific constraints.

Example constraints.txt

# Contents of contraints.txt

cloudify-plugins-common===3.4.2

Wagons are often specific to the OS/Platform/Distribution/Architecture that they were built on. For example, your build your wagon on Ubuntu 16.04, then the wagon may not work on Centos 6. Make sure to test your wagon on the same kind of machine that you intend to use it on.

Install Wagon Package

In order to install the Wagon package within virtualenv use pip:

source <path to virtualenv>/bin/activate
pip install wagon==0.11.0

Or install from source code:

source <path to virtualenv>/bin/activate
git clone https://github.com/cloudify-cosmo/wagon.git
cd wagon
pip install .

Usage

When using Wagon version 0.3.2:

$ wagon create -s path/to/python/project.zip -a '--no-cache-dir -c path/to/constraints.txt'

When using Wagon version 0.11.0:

$ wagon create -r /path/to/requirements/file/if/exits -v -f -a '--no-cache-dir -c path/to/constraints.txt' .

Build py2py3 wagon

Studio Conductor official plugins are Python 2 and Python 3 compatible. In order to support installation of a wagon on both py2(5.0.5 and older) and py3 managers(5.1 and newer), py2py3 wagon introduced.

py2py3 wagon is a wagon that contains all the Python2 wheels and Python3 wheels required for the plugin installation.

From version 0.10.0 --pip flag introduced, when adding --pip flag to wagon command the wagon code use the specified pip in order to download the wheels.

This way py2py3 wagons can be created.

For example :

$ wagon create --pip /env2/bin/pip --pip /env3/bin/pip --pyver "27" --pyver "36" -r /path/to/requirements/file -v -f -a '--no-cache-dir -c path/to/constraints.txt' path/to/plugin/source

Here env2 is Python 2.7 virtualenv and env3 is Python 3.6 virtualenv.

To learn more about how to use wagon, see the Wagon documentation.

Build wagons with Studio Conductor wagon builder Docker images

In order to build wagons easily on every operation system, wagon builders docker images provided in cloudifyplatform dockerhub repository.

For example in order to build aws plugin wagon on centos 7 OS run:

$ docker run -v path/to/cloudify-aws-plugin/:/packaging cloudifyplatform/cloudify-centos-7-py2py3-wagon-builder

The wagon can be found under path/to/cloudify-aws-plugin directory.