wagon 0.1.2

Creates Python Wheel based archives.

A wagon (also spelt waggon in British and Commonwealth English) is a heavy four-wheeled vehicle pulled by draught animals, used for transporting goods, commodities, agricultural materials, supplies, and sometimes people. Wagons are distinguished from carts, which have two wheels, and from lighter four-wheeled vehicles primarily for carrying people, such as carriages.

• Master Branch

• PyPI

• Version

Wagon creates tar.gz based archives containing sets of Python Wheels for a single module with its dependencies and allows to install them.

(NOTE: Currently, only tested on Linux).

Cloudify Plugins are packaged as sets of Python Wheels in tar.gz files and so we needed a tool to create such archives. Hence, Wagon.

Installation

pip install wagon

Usage

Create Packages

wagon create --help

Examples

# create an archive by retrieving the source from PyPI and keep the downloaded wheels (kept under <cwd>/plugin)
wagon create -s cloudify-script-plugin==1.2 --keep-wheels -v
# create an archive package by retrieving the source from a URL and creates wheels from requirement files found within the archive.
wagon create -s http://github.com/cloudify-cosmo/cloudify-script-plugin/archive/1.2.tar.gz -r .
# create an archive package by retrieving the source from a local path and output the tar.gz file to /tmp/<MODULE>.tar.gz (defaults to <cwd>/<MODULE>.tar.gz)
wagon create -s ~/modules/cloudify-script-plugin/ -o /tmp/

The output package of the three commands should be something like cloudify_script_plugin-1.2-py27-none-any.tar.gz if running under Python 2.7.x.

Install Packages

wagon install --help

Examples

# install a packaged module from a local package tar file and upgrade if already installed
wagon install -s ~/tars/cloudify_script_plugin-1.2-py27-none-any.tar.gz --upgrade
# install a packaged module from a url into an existing virtualenv
wagon install -s http://me.com/cloudify_script_plugin-1.2-py27-none-any.tar.gz --virtualenv my_venv -v

Validate Packages

wagon validate --help

Examples

# validate that a package is a wagon compatible package
wagon validate -s ~/tars/cloudify_script_plugin-1.2-py27-none-any.tar.gz
# validate from a url
wagon validate -s http://me.com/cloudify_script_plugin-1.2-py27-none-any.tar.gz

Naming and Versioning

Source: PyPI

When providing a PyPI source, it must be supplied as MODULE_NAME==MODULE_VERSION. wagon then applies the correct name and version to the archive according to the two parameters.

Source: Else

For local path and URL sources, the name and version are automatically extracted from the setup.py file.

NOTE: This means that when supplying a local path, you must supply a path to the root of where your setup.py file resides.

NOTE: If using a URL, it must be a URL to a tar.gz file structured like a GitHub tar.gz archive (e.g. https://github.com/cloudify-cosmo/cloudify-script-plugin/archive/master.tar.gz)

Metadata File and Wheels

A Metadata file is generated for the archive and looks somewhat like this:

{
    "archive_name": "cloudify_script_plugin-1.2-py27-none-any.tar.gz",
    "build_server_os_properties": {
        "distribution": "ubuntu",
        "distribution_release": "trusty",
        "distribution_version": "14.04"
    },
    "module_name": "cloudify-script-plugin",
    "module_source": "cloudify-script-plugin==1.2",
    "module_version": "1.2",
    "supported_platform": "any",
    "wheels": [
        "proxy_tools-0.1.0-py2-none-any.whl",
        "bottle-0.12.7-py2-none-any.whl",
        "networkx-1.8.1-py2-none-any.whl",
        "pika-0.9.13-py2-none-any.whl",
        "cloudify_plugins_common-3.2.1-py2-none-any.whl",
        "requests-2.7.0-py2.py3-none-any.whl",
        "cloudify_rest_client-3.2.1-py2-none-any.whl",
        "cloudify_script_plugin-1.2-py2-none-any.whl"
    ]
}

• The wheels to be installed reside in the tar.gz file under ‘wheels/*.whl’.

• The Metadata file resides in the tar.gz file under ‘module.json’.

• The installer uses the metadata file to check that the platform fits the machine the module is being installed on.

• The OS properties are specifically helpful to identify Linux distributions and their releases as compiled Wheels may vary between them.

Archive naming convention and Platform

The tar.gz archive is named according to the Wheel naming convention described in PEP0427 aside from two fields:

Example: cloudify_fabric_plugin-1.2.1-py27-none-linux_x86_64.tar.gz

• {python tag}: The Python version is set by the Python running the packaging process. That means that while a module might run on both py27 and py33 (for example), since the packaging process took place using Python 2.7, only py27 will be appended to the name. Note that we will be providing a way for the user to provide the supported Python versions explicitly.

• {platform tag}: The platform (e.g. linux_x86_64, win32) is set for a specific wheel. To know which platform the module can be installed on, all wheels are checked. If a specific wheel has a platform property other than any, that platform will be used as the platform of the package. Of course, we assume that there can’t be wheels downloaded or created on a specific machine platform that belongs to two different platforms.