.. _technical:

************************
Technical specifications
************************

(Spécification technique)

Constraints
===========

L'exercice est donc l'écriture d'un script Python qui prendrait les
données du dépôt d'une de nos applications (prenons Passerelle :
https://git.entrouvert.org/passerelle.git) et afficherait ces taux.

NB : on est bien sur un script simple, pas sur du web.

Library
=======

We need a Library to interact with ``git`` repositories.
Specifically, we need an API to parse the result of ``git log``:
::
   
  $ git log | head
  commit 1d8e084753d93602aec7a6260eaa4816c3281cc2
  Author: Nicolas Roche <nroche@narval.fr.eu.org>
  Date:   Fri Nov 9 16:22:49 2018 +0100

      document how to build documentation
  ...

Here is a "stabilized" library:
::
   
   # apt-get install python-git-doc

Unfortunately it doesn't perform any parsing, but just return a big string:
::
   
  # apt-get install python-git
  $ python
  >>> import git
  >>> g = git.Git('/home/nroche/git/keepcool')
  >>> log = g.log()
  >>> print log
  ...
  >>> type(log)
  <type 'unicode'>

It seems we need to play with ``git`` command line's option and pass it to the ``log()`` function.
::
   
  $ git log --committer=nroche \
            --after="2018-11-09 16:05:00" --before="2018-11-09 16:20:00" \
            --pretty='"%cN" %ct'
  "Nicolas Roche" 1541776456
  "Nicolas Roche" 1541776017
  $ python
  >>> import git
  >>> g = git.Git('/home/nroche/git/keepcool')
  >>> print g.log('--pretty="%cN" %ct')
  "Nicolas Roche" 1541776969
  "Nicolas Roche" 1541776456
  ...

.. _no git remote access: https://stackoverflow.com/questions/20055398/is-it-possible-to-get-commit-logs-messages-of-a-remote-git-repo-without-git-clon

Sadly it seems to me that the only way to interact with a ``git`` repository is to clone it first (see `no git remote access`_).

Logs
====

Not necessary as we do not develop a daemon. Traces may be sufficient.

Conclusion
==========

* For now, we will use ``python-git`` library.

* We first need to clone the remote ``git`` repositories we want to inspect.

* We will get dates using the unix timestamp format (easier to parse)