
Scriptharness
*************

Scriptharness is a framework for writing scripts.  There are three
core principles: full logging, flexible configuration, and modular
actions.  The goal of *full logging* is to be able to debug problems
purely through the log.  The goal of *flexible configuration* is to
make each script useful in a variety of contexts and environments.
The goals of *modular actions* are a) faster development feedback
loops and b) different workflows for different usage requirements.


Full logging
============

Many scripts log.  However, logging can happen sporadically, and it's
generally acceptable to run a number of actions silently (e.g.,
"os.chdir()" will happily change directories with no indication in the
log).  In *full logging*, the goal is to be able to debug bustage
purely through the log.

At the outset, the user can add a generic logging wrapper to any
method with minimal fuss.  As scriptharness matures, there will be
more customized wrappers to use as drop-in replacements for
previously-non-logging methods.


Flexible configuration
======================

Many scripts use some sort of configuration, whether hardcoded, in a
file, or through the command line.  A family of scripts written by the
same author(s) may have similar configuration options and patterns,
but often times they vary wildly from script to script.

By offering a standard way of accepting configuration options, and
then exporting that config to a file for later debugging or
replication, scriptharness makes things a bit neater and cleaner and
more familiar between scripts.

By either disallowing runtime configuration changes, or by explicitly
logging them, scriptharness removes some of the guesswork when
debugging bustage.


Modular actions
===============

Scriptharness actions allow for:

* faster development feedback loops.  No need to rerun the entirety
  of a long-running script when trying to debug a single action inside
  that script.

* different workflows for different usage requirements, such as
  running standalone versus running in cloud infrastructure

This is in the same spirit of other frameworks that allow for discrete
targets, tasks, or actions: make, maven, ansible, and many more.


Running unit tests
==================


Linux and OS X
--------------

   # By default, this will look for python 2.7 + 3.{3,4,5}.
   # You can run |tox -e ENV| to run a specific env, e.g. |tox -e py27|
   pip install tox
   tox


Windows
-------

   # By default, this will look for python 2.7 + 3.4
   # You can run |tox -c tox_win.ini -e ENV| to run a specific env, e.g. |tox -c tox_win.ini -e py27|
   pip install tox
   tox -c win.ini
