Merge lp:~canonical-isd-hackers/django-preflight/documentation into lp:django-preflight

[Łukasz Czyżykowski]

Add documentation.

Add documentation for project.

[lp:~canonical-isd-hackers/django-preflight/documentation]

10. By Łukasz Czyżykowski on 2011-02-10

Removed doc/_build from the branch.

[Anthony Lenton (elachuni)]

Discussed via IRC, implemented a couple of very small fixes. Docs look great.

review: Approve

[lp:~canonical-isd-hackers/django-preflight/documentation]

11. By Łukasz Czyżykowski on 2011-02-10

Fixed typos in docs.

=== modified file '.bzrignore'
--- .bzrignore	2011-02-07 16:06:51 +0000
+++ .bzrignore	2011-02-10 12:30:10 +0000
@@ -2,4 +2,5 @@
 build
 dist
 .tox
-*.egg-info
\ No newline at end of file
+*.egg-info
+doc/_build
\ No newline at end of file

=== removed file 'INSTALL'
=== modified file 'README'
--- README	2011-02-07 16:06:51 +0000
+++ README	2011-02-10 12:30:10 +0000
@@ -0,0 +1,25 @@
+=================
+Django Pre-flight
+=================
+
+Overview
+========
+
+Django Pre-flight is meant to help with creation of simple pages on
+which one can quickly gauge health of the system and its external
+dependencies. It's a great help for testers before actually delving
+into the system to be sure that all is configured correctly and any
+found problems are due to bugs in the code itself and not because of
+misconfiguration.
+
+This project provides framework for creating set of checks (methods)
+which determine the health of the system, a way of executing all of
+them and gathering the results. You can either see the result via the
+web interface or using Django's ``manage.py`` command.
+
+Additionally the web page displays the versions of various system
+components, like Python, Django, django-preflight itself. This
+versions list also have a way of extending it to include project's
+specific bits of information.
+
+More information can be found in ``doc/`` directory.

=== added directory 'doc'
=== added file 'doc/Makefile'
--- doc/Makefile	1970-01-01 00:00:00 +0000
+++ doc/Makefile	2011-02-10 12:30:10 +0000
@@ -0,0 +1,89 @@
+# Makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line.
+SPHINXOPTS    =
+SPHINXBUILD   = sphinx-build
+PAPER         =
+BUILDDIR      = _build
+
+# Internal variables.
+PAPEROPT_a4     = -D latex_paper_size=a4
+PAPEROPT_letter = -D latex_paper_size=letter
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+
+.PHONY: help clean html dirhtml pickle json htmlhelp qthelp latex changes linkcheck doctest
+
+help:
+	@echo "Please use \`make <target>' where <target> is one of"
+	@echo "  html      to make standalone HTML files"
+	@echo "  dirhtml   to make HTML files named index.html in directories"
+	@echo "  pickle    to make pickle files"
+	@echo "  json      to make JSON files"
+	@echo "  htmlhelp  to make HTML files and a HTML help project"
+	@echo "  qthelp    to make HTML files and a qthelp project"
+	@echo "  latex     to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
+	@echo "  changes   to make an overview of all changed/added/deprecated items"
+	@echo "  linkcheck to check all external links for integrity"
+	@echo "  doctest   to run all doctests embedded in the documentation (if enabled)"
+
+clean:
+	-rm -rf $(BUILDDIR)/*
+
+html:
+	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
+
+dirhtml:
+	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
+	@echo
+	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
+
+pickle:
+	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
+	@echo
+	@echo "Build finished; now you can process the pickle files."
+
+json:
+	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
+	@echo
+	@echo "Build finished; now you can process the JSON files."
+
+htmlhelp:
+	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
+	@echo
+	@echo "Build finished; now you can run HTML Help Workshop with the" \
+	      ".hhp project file in $(BUILDDIR)/htmlhelp."
+
+qthelp:
+	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
+	@echo
+	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
+	      ".qhcp project file in $(BUILDDIR)/qthelp, like this:"
+	@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/django-preflight.qhcp"
+	@echo "To view the help file:"
+	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/django-preflight.qhc"
+
+latex:
+	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
+	@echo
+	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
+	@echo "Run \`make all-pdf' or \`make all-ps' in that directory to" \
+	      "run these through (pdf)latex."
+
+changes:
+	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
+	@echo
+	@echo "The overview file is in $(BUILDDIR)/changes."
+
+linkcheck:
+	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
+	@echo
+	@echo "Link check complete; look for any errors in the above output " \
+	      "or in $(BUILDDIR)/linkcheck/output.txt."
+
+doctest:
+	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
+	@echo "Testing of doctests in the sources finished, look at the " \
+	      "results in $(BUILDDIR)/doctest/output.txt."

=== added directory 'doc/_static'
=== added directory 'doc/_templates'
=== added file 'doc/authentication.rst'
--- doc/authentication.rst	1970-01-01 00:00:00 +0000
+++ doc/authentication.rst	2011-02-10 12:30:10 +0000
@@ -0,0 +1,61 @@
+Authentication
+==============
+
+
+Defaults
+--------
+
+Due to high sensitivity of the information provided on preflight page
+it's highly advisable to limit access to it.
+
+By default only registered users which have access to Django admin can
+see that page and all the rest will get a 404 error page.
+
+
+Customization
+-------------
+
+But if this is not enough or if you need some other way of assesing
+the access right you can provide your own code.
+
+Each preflight class can have an ``authenticate(self, request)``
+method which gets a request object and returns ``True`` if given
+request is authorized to access that page. Otherwise the 404 error
+code will be returned.
+
+
+Multiple preflight files
+------------------------
+
+As you may have noticed, the ``authenticate`` method is supplied for
+each application and not for whole project. This brings the question
+what would happen if two or more applications contain ``authenticate``
+method?
+
+In that case, given request must have be approved by all the
+``authentication`` methods before the page is displayed. It's enough
+for just one to veto the access. This means, that you can only tighten
+up the security when adding new preflight classes, never loosen it up.
+
+
+Example
+-------
+
+Below is quick example of implementing very simple way of
+authorization schema. This particular one only allows one user to
+access this page:
+
+.. testcode::
+
+    import preflight
+
+    class AppPreflight(preflight.Preflight):
+    
+        def authenticate(self, request):
+            if request.user.username == 'blackknight':
+                return True
+
+    preflight.register(AppPreflight)
+
+.. testoutput::
+   :hide:

=== added file 'doc/conf.py'
--- doc/conf.py	1970-01-01 00:00:00 +0000
+++ doc/conf.py	2011-02-10 12:30:10 +0000
@@ -0,0 +1,196 @@
+# -*- coding: utf-8 -*-
+#
+# django-preflight documentation build configuration file, created by
+# sphinx-quickstart on Tue Feb  8 15:23:58 2011.
+#
+# This file is execfile()d with the current directory set to its containing dir.
+#
+# Note that not all possible configuration values are present in this
+# autogenerated file.
+#
+# All configuration values have a default; values that are commented out
+# serve to show the default.
+
+import sys, os
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+sys.path.append(os.path.abspath('..'))
+
+os.environ['DJANGO_SETTINGS_MODULE'] = 'example_project.settings'
+
+# -- General configuration -----------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be extensions
+# coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
+extensions = ['sphinx.ext.doctest']
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ['_templates']
+
+# The suffix of source filenames.
+source_suffix = '.rst'
+
+# The encoding of source files.
+#source_encoding = 'utf-8'
+
+# The master toctree document.
+master_doc = 'index'
+
+# General information about the project.
+project = u'django-preflight'
+copyright = u'2011, Łukasz Czyżykowski'
+
+# The version info for the project you're documenting, acts as replacement for
+# |version| and |release|, also used in various other places throughout the
+# built documents.
+#
+# The short X.Y version.
+version = '0.1'
+# The full version, including alpha/beta/rc tags.
+release = '0.1'
+
+# The language for content autogenerated by Sphinx. Refer to documentation
+# for a list of supported languages.
+#language = None
+
+# There are two options for replacing |today|: either, you set today to some
+# non-false value, then it is used:
+#today = ''
+# Else, today_fmt is used as the format for a strftime call.
+#today_fmt = '%B %d, %Y'
+
+# List of documents that shouldn't be included in the build.
+#unused_docs = []
+
+# List of directories, relative to source directory, that shouldn't be searched
+# for source files.
+exclude_trees = ['_build']
+
+# The reST default role (used for this markup: `text`) to use for all documents.
+#default_role = None
+
+# If true, '()' will be appended to :func: etc. cross-reference text.
+#add_function_parentheses = True
+
+# If true, the current module name will be prepended to all description
+# unit titles (such as .. function::).
+#add_module_names = True
+
+# If true, sectionauthor and moduleauthor directives will be shown in the
+# output. They are ignored by default.
+#show_authors = False
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = 'sphinx'
+
+# A list of ignored prefixes for module index sorting.
+#modindex_common_prefix = []
+
+
+# -- Options for HTML output ---------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  Major themes that come with
+# Sphinx are currently 'default' and 'sphinxdoc'.
+html_theme = 'default'
+
+# Theme options are theme-specific and customize the look and feel of a theme
+# further.  For a list of options available for each theme, see the
+# documentation.
+#html_theme_options = {}
+
+# Add any paths that contain custom themes here, relative to this directory.
+#html_theme_path = []
+
+# The name for this set of Sphinx documents.  If None, it defaults to
+# "<project> v<release> documentation".
+#html_title = None
+
+# A shorter title for the navigation bar.  Default is the same as html_title.
+#html_short_title = None
+
+# The name of an image file (relative to this directory) to place at the top
+# of the sidebar.
+#html_logo = None
+
+# The name of an image file (within the static path) to use as favicon of the
+# docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
+# pixels large.
+#html_favicon = None
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+html_static_path = ['_static']
+
+# If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
+# using the given strftime format.
+#html_last_updated_fmt = '%b %d, %Y'
+
+# If true, SmartyPants will be used to convert quotes and dashes to
+# typographically correct entities.
+#html_use_smartypants = True
+
+# Custom sidebar templates, maps document names to template names.
+#html_sidebars = {}
+
+# Additional templates that should be rendered to pages, maps page names to
+# template names.
+#html_additional_pages = {}
+
+# If false, no module index is generated.
+#html_use_modindex = True
+
+# If false, no index is generated.
+#html_use_index = True
+
+# If true, the index is split into individual pages for each letter.
+#html_split_index = False
+
+# If true, links to the reST sources are added to the pages.
+#html_show_sourcelink = True
+
+# If true, an OpenSearch description file will be output, and all pages will
+# contain a <link> tag referring to it.  The value of this option must be the
+# base URL from which the finished HTML is served.
+#html_use_opensearch = ''
+
+# If nonempty, this is the file name suffix for HTML files (e.g. ".xhtml").
+#html_file_suffix = ''
+
+# Output file base name for HTML help builder.
+htmlhelp_basename = 'django-preflightdoc'
+
+
+# -- Options for LaTeX output --------------------------------------------------
+
+# The paper size ('letter' or 'a4').
+#latex_paper_size = 'letter'
+
+# The font size ('10pt', '11pt' or '12pt').
+#latex_font_size = '10pt'
+
+# Grouping the document tree into LaTeX files. List of tuples
+# (source start file, target name, title, author, documentclass [howto/manual]).
+latex_documents = [
+  ('index', 'django-preflight.tex', u'django-preflight Documentation',
+   u'Łukasz Czyżykowski', 'manual'),
+]
+
+# The name of an image file (relative to this directory) to place at the top of
+# the title page.
+#latex_logo = None
+
+# For "manual" documents, if this is true, then toplevel headings are parts,
+# not chapters.
+#latex_use_parts = False
+
+# Additional stuff for the LaTeX preamble.
+#latex_preamble = ''
+
+# Documents to append as an appendix to all manuals.
+#latex_appendices = []
+
+# If false, no module index is generated.
+#latex_use_modindex = True

=== added file 'doc/configure.rst'
--- doc/configure.rst	1970-01-01 00:00:00 +0000
+++ doc/configure.rst	2011-02-10 12:30:10 +0000
@@ -0,0 +1,28 @@
+Configuration
+=============
+
+You can customize django-preflight's behaviour in several
+ways. Easiest one is to use configuration options.
+
+
+``settings.py``
+---------------
+
+``PREFLIGHT_BASE_TEMPLATE`` Name of the base template which will be
+  extended by preflight's page. It should contain ``title`` and
+  ``content`` blocks.
+
+  Default: ``index.1col.html``
+
+``PREFLIGHT_TABLE_CLASS``
+  A name of the CSS class which will be applied to the tables on the
+  overview page.
+
+  Default: ``listing``
+
+
+Other customizations
+--------------------
+
+Other ways in which you can customize django-preflight are tightly
+coupled with creating checks and are discussed in the next section.

=== added file 'doc/creating-checks.rst'
--- doc/creating-checks.rst	1970-01-01 00:00:00 +0000
+++ doc/creating-checks.rst	2011-02-10 12:30:10 +0000
@@ -0,0 +1,85 @@
+Creating checks
+===============
+
+Conventions
+-----------
+
+There are four steps to create a check:
+
+ 1. Create ``preflight.py`` file in your application's directory.
+ 2. In that file create a class which inherits from
+    ``preflight.Preflight``.
+ 3. Add a method to that class with name starting with ``check_``.
+ 4. Register that class by calling ``preflight.register(ClassName)``
+
+Those check methods are used by web interface and by command line
+one. You can see the results of them being run by either accessing the
+preflight page or by running ``$ ./manage.py preflight`` command.
+
+
+Check's description
+-------------------
+
+The docstring of the method is displayed on the web page as a
+description of the check. You can use it to document what it is
+checking and what to do in case it fails. Ideally, one should check
+only one thing, so reason of the failure would be obvious.
+
+
+Success or Failure
+------------------
+
+To the check to be considered successful it needs to return a
+``True``. Returning ``False`` or raising an exception means that the
+check have failed. The system records the results from all the checks
+from all of the applications and presents it to the end user.
+
+
+An Example
+----------
+
+Below is an example of simple preflight class which checks if cache is
+accessible from Django's process:
+
+.. testcode::
+
+    # this line is required for Python versions < 
+    from __future__ import absolute_import
+    
+    import preflight
+
+
+    class AppPreflight(preflight.Preflight):
+
+        def check_cache_is_accessible(self):
+            """
+            Try to access cache, if it fails that means the caching
+            is not properly configured or the cache server is down.
+            """
+            from django.core.cache import cache
+            cache.set('test', 'value')
+            if cache.get('test') == 'value':
+                cache.delete('test')
+                return True
+            else:
+                return False
+
+    preflight.register(AppPreflight)
+    
+.. testoutput::
+   :hide:
+
+If everything is properly configured this check method will return
+``True``, which means that it succeeded.
+
+But if something is wrong, like, for example, missing python-memcached
+library, the exception will be raised and will cause this check to
+fail.
+
+Third option is when this check returns ``False``, which means
+that the cache is accessible, but is not storing proper values. Not a
+good sign either.
+
+.. note:: I'm aware this check can fail for more than one reason. It
+          would be possible to split it into two smaller checks, but
+          that would only made this example more complicated.

=== added file 'doc/index.rst'
--- doc/index.rst	1970-01-01 00:00:00 +0000
+++ doc/index.rst	2011-02-10 12:30:10 +0000
@@ -0,0 +1,25 @@
+.. django-preflight documentation master file, created by
+   sphinx-quickstart on Tue Feb  8 15:23:58 2011.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Welcome to django-preflight's documentation!
+============================================
+
+Contents:
+
+.. toctree::
+   :maxdepth: 2
+
+   install
+   configure
+   creating-checks
+   authentication
+   versions
+   manage-command
+
+Search
+======
+
+* :ref:`search`
+

=== added file 'doc/install.rst'
--- doc/install.rst	1970-01-01 00:00:00 +0000
+++ doc/install.rst	2011-02-10 12:30:10 +0000
@@ -0,0 +1,75 @@
+Install django-preflight
+========================
+
+Install the code
+----------------
+
+django-preflight is just a regular Django application and only
+requirement for it to be usable is to be importable by Django
+project. That means you can put it directly into your project's
+directory and it will work just find. Alternatively you can install it
+using common python tools:::
+
+    $ pip install django-preflight
+
+or::
+
+    $ easy_install django-preflight
+
+Or even download the source code and run::
+
+    $ python setup.py install
+
+from the source code directory.
+
+
+Update ``settings.py``
+----------------------
+
+Once the code is installed you need to setup your Django's project
+properly. First thing is to include it in ``INSTALLED_APPS`` list::
+
+    # settings.py
+    INSTALLED_APPS = (
+        ...
+        'preflight',
+        ...
+    )
+
+django-preflight by itself doesn't have any extra dependecies.
+
+Because this project doesn't include any database models, there's no
+need of updating your database schema.
+
+
+Update ``urls.py``
+------------------
+
+Last bit of configuration is to include django-preflight into the
+project's ``urls.py`` file. It should look like the following:
+
+.. testcode::
+
+    from django.conf.urls.defaults import *
+
+    import preflight
+    import preflight.urls
+    
+    
+    preflight.autodiscover()
+    
+    urlpatterns = patterns('',
+        (r'^preflight/', include(preflight.urls)),
+    )
+
+.. testoutput::
+   :hide:
+
+Two things here. Line with ``include(preflight.urls)`` sets the URL on
+which the preflight page will be accessible. You can make this
+anything you want, here it's set to ``/preflight/``.
+
+Second is ``preflight.autodiscover()`` call which triggers search for
+``preflight.py`` modules in all installed applications. Similar to
+Django's admin ``admin.autodiscover()`` call.  This enables you to
+just drop such file into your application folder.

=== added file 'doc/manage-command.rst'
--- doc/manage-command.rst	1970-01-01 00:00:00 +0000
+++ doc/manage-command.rst	2011-02-10 12:30:10 +0000
@@ -0,0 +1,42 @@
+Management Command
+==================
+
+
+Command
+-------
+
+Together with web page on which you can check the results of all your
+checks django-preflight provides a Django management command. This
+allows you to make sure that all is properly configured without the
+need of going through the web server.
+
+It can even be incorporated as a part of automatic health checks (or
+other scripts), as it properly returns the exit codes. 0 if everything
+is working and 1 otherwise.
+
+
+Usage
+-----
+
+The invocation of the command is very simple. Once you have the app
+installed just use::
+
+    $ python manage.py preflight
+
+which should return something similar to the following::
+
+    Pre-flight checks for applications
+    ====================================================
+    
+    app checks
+    ----------------------------------------------------
+    media_root_is_writable                          OK
+    cache_is_usable                                 OK
+    twitter_api_key_is_correct                      OK
+
+
+of course, the exact result will highly depend on the exact checks,
+project's structure and django-preflight configuration.
+
+In case of any check failures the ``OK`` will be replaced with
+``ERROR`` status.

=== added file 'doc/versions.rst'
--- doc/versions.rst	1970-01-01 00:00:00 +0000
+++ doc/versions.rst	2011-02-10 12:30:10 +0000
@@ -0,0 +1,79 @@
+Versions
+========
+
+Version's List
+--------------
+
+Besides checks django-preflight provides a list of versions for
+various components. That information is only accessible via web
+interface, because it's very easy to get that information from the
+command line.
+
+Naturally you have an ability to extend this information with any
+other component you like. By default it contains versions of: Python,
+Django and django-preflight itself.
+
+
+Extending Versions List
+-----------------------
+
+As with other things, main extension point is ``Preflight`` class. You
+can either add ``versions(self)`` method, which should return list of
+dictionaries, each one containing ``name`` and ``version`` keys or add
+class attribute called ``versions`` containing the same information.
+
+The method version can be useful if you want to check some items
+dynamically or include them only if they are available and skipping
+them otherwise.
+
+
+Method Example
+--------------
+
+An example where ``versions`` is a method:
+
+.. testcode::
+
+    import preflight
+
+    class AppPreflight(preflight.Preflight):
+        def versions(self):
+            try:
+                import simplejson
+                return [{'name': "simplejson", 
+                         'version': simplejson.__version__}]
+            except ImportError:
+                return []
+
+    preflight.register(AppPreflight)
+
+.. testoutput::
+   :hide:
+
+In this case, if simplejson is available its version will be added to
+the list of packages displayed by django-preflight.
+
+
+Attribute Example
+-----------------
+
+An example where ``versions`` is an iterable:
+
+.. testcode::
+
+    import preflight
+    import setuptools
+    
+    class AppPreflight(preflight.Preflight):
+ 
+        versions = [
+            {'name': "setuptools", 'version': setuptools.__version__}
+        ]
+
+    preflight.register(AppPreflight)
+
+.. testoutput::
+   :hide:
+
+On the other hand, this example causes the app to require
+``setuptools`` to be installed and will fail if this is not the case.

=== modified file 'tox.ini'
--- tox.ini	2011-02-07 16:06:51 +0000
+++ tox.ini	2011-02-10 12:30:10 +0000
@@ -1,11 +1,20 @@
 [tox]
 envlist = 
         py26-django124, py26-django113, py26-django104, py26-django-beta,
-        py27-django124, py27-django113, py27-django104, py27-django-beta
+        py27-django124, py27-django113, py27-django104, py27-django-beta,
+        docs
 
 [testenv]
 commands = python setup.py test
 
+[testenv:docs]
+basepython=python
+changedir=doc
+deps=sphinx
+commands=
+    sphinx-build -b doctest -d {envtmpdir}/doctrees . {envtmpdir}/doctest
+    sphinx-build -W -b html -d {envtmpdir}/doctrees . {envtmpdir}/html
+
 [testenv:py26-django124]
 basepython = python2.6
 deps = http://www.djangoproject.com/download/1.2.4/tarball/