Installing for Developers

Installing Prerequisites

Developing the Custodian requires a make/C toolchain, Python 2.7, Python 3.6, and some basic Python tools.

On Ubuntu

For Python 2.7:

$ sudo apt-get install python2.7 python2.7-dev python-pip

Python 3.6 is more complicated.

On macOS with Homebrew

$ brew install python python3

Basic Python Tools

$ pip install -U pip virtualenv tox

Installing Custodian

First, clone the repository:

$ git clone
$ cd cloud-custodian

Then build the software with tox:

$ tox

Tox creates a sandboxed “virtual environment” (“virtualenv”) for each Python version, 2.7 and 3.6. These are stored in the .tox/ directory. It then runs the test suite under both versions of Python, per the tox.ini file. You can run the test suite in a single enviroment with the -e flag:

$ tox -e py27

To access the executables installed in one or the other virtual environment, source the virtualenv into your current shell, e.g.:

$ source .tox/py27/bin/activate

You should then have, e.g., the custodian command available:

(py27)$ custodian -h

You’ll also be able to invoke nosetests or pytest directly with the arguments of your choosing, e.g.:

(py27) $ pytest tests/ -x