.. _contributing:

=========================

Contributing to Kallithea

=========================

Kallithea is developed and maintained by its users. Please join us and scratch

your own itch.

Infrastructure

--------------

The main repository is hosted at Our Own Kallithea (aka OOK) on

https://kallithea-scm.org/repos/kallithea/ (which is our self-hosted instance

of Kallithea).

For now, we use Bitbucket_ for `Pull Requests`_ and `Issue Tracker`_ services. The

issue tracker is for tracking bugs, not for "support", discussion or ideas -

please use the `mailing list`_ to reach the community.

We use Weblate_ to translate the user interface messages into languages other

than English. Join our project on `Hosted Weblate`_ to help us.

To register, you can use your Bitbucket or GitHub account.

Getting started

---------------

To get started with development::

        hg clone https://kallithea-scm.org/repos/kallithea

        cd kallithea

        virtualenv ../kallithea-venv

        source ../kallithea-venv/bin/activate

        python setup.py develop

        paster make-config Kallithea my.ini

        paster setup-db my.ini --user=user --email=user@example.com --password=password --repos=/tmp

        paster serve my.ini --reload &

        firefox http://127.0.0.1:5000/

You can also start out by forking https://bitbucket.org/conservancy/kallithea

on Bitbucket_ and create a local clone of your own fork.

Running tests

-------------

After finishing your changes make sure all tests pass cleanly. You can run

the testsuite running ``nosetest`` from the project root, or if you use tox

run tox for python2.6-2.7 with multiple database test. When using `nosetests`

to change your testing enviroment.

    paster serve test.ini --pid-file=test.pid --daemon

    KALLITHEA_WHOOSH_TEST_DISABLE=1 KALLITHEA_NO_TMP_PATH=1 nosetests -x kallithea/tests/other/test_vcs_operations.py

    kill -9 $(cat test.pid)

Coding/contribution guidelines

------------------------------

Kallithea is GPLv3 and we assume all contributions are made by the

committer/contributor and under GPLv3 unless explicitly stated. We do care a

lot about preservation of copyright and license information for existing code

that is brought into the project.

We don't have a formal coding/formatting standard. We are currently using a mix

of Mercurial (http://mercurial.selenic.com/wiki/CodingStyle), pep8, and

consistency with existing code. Run whitespacecleanup.sh to avoid stupid

whitespace noise in your patches.

We support both Python 2.6.x and 2.7.x and nothing else. For now we don't care

about Python 3 compatibility.

We try to support the most common modern web browsers. IE8 is still supported

to the extent it is feasible but we may stop supporting it very soon.

We primarily support Linux and OS X on the server side but Windows should also work.

Html templates should use 2 spaces for indentation ... but be pragmatic. We

should use templates cleverly and avoid duplication. We should use reasonable

semantic markup with classes and ids that can be used for styling and testing.

We should only use inline styles in places where it really is semantic (such as

display:none).

JavaScript must use ';' between/after statements. Indentation 4 spaces. Inline

multiline functions should be indented two levels - one for the () and one for

{}. jQuery value arrays should have a leading $.

Commit messages should have a leading short line summarizing the changes. For

bug fixes, put "(Issue #123)" at the end of this line.

Contributions will be accepted in most formats - such as pull requests on

bitbucket, something hosted on your own Kallithea instance, or patches sent by

mail to the kallithea-general mailing list.

Make sure to test your changes both manually and with the automatic tests

before posting.

We care about quality and review and keeping a clean repository history. We

might give feedback that requests polishing contributions until they are

"perfect". We might also rebase and collapse and make minor adjustments to your

changes when we apply them.

We try to make sure we have consensus on the direction the project is taking.

Everything non-sensitive should be discussed in public - preferably on the

mailing list.  We aim at having all non-trivial changes reviewed by at least

one other core developer before pushing. Obvious non-controversial changes will

be handled more casually.

For now we just have one official branch ("default") and will keep it so stable

that it can be (and is) used in production. Experimental changes should live

elsewhere (for example in a pull request) until they are ready.

"Roadmap"

---------

We do not have a road map but are waiting for your contributions. Here are some

ideas of places we might want to go - contributions in these areas are very

welcome:

* Front end:

    * kill YUI - more jQuery

    * remove other dependencies - especially the embedded cut'n'pasted ones

    * remove hardcoded styling in templates, make markup more semantic while moving all styling to css

    * switch to bootstrap or some other modern UI library and cleanup of style.css and contextbar.css

    * new fancy style that looks good

* testing

    * better test coverage with the existing high level test framework

    * test even more high level and javascript - selenium/robot and splinter seems like the top candidates

    * more unit testing

* code cleanup

    * move code from templates to controllers and from controllers to libs or models

    * more best practice for web apps and the frameworks

* features

    * relax dependency version requirements after thorough testing

    * support for evolve

    * updates of PRs ... while preserving history and comment context

    * auto pr merge/rebase

    * ssh

    * bitbucket compatible wiki

    * realtime preview / wysiwyg when editing comments and files

    * make journal more useful - filtering on branches and files

    * community mode with self registration and personal space

    * improve documentation

Thank you for your contribution!

--------------------------------

.. _Weblate: http://weblate.org/

.. _Issue Tracker: https://bitbucket.org/conservancy/kallithea/issues?status=new&status=open

.. _Pull Requests: https://bitbucket.org/conservancy/kallithea/pull-requests

.. _bitbucket: http://bitbucket.org/

.. _mailing list: http://lists.sfconservancy.org/mailman/listinfo/kallithea-general

.. _Hosted Weblate: https://hosted.weblate.org/projects/kallithea/kallithea/

.. _installation:

==========================

Installation on Unix/Linux

==========================

**Kallithea** is written entirely in Python.  Kallithea requires Python version

2.6 or higher.

.. Note:: Alternative very detailed installation instructions for Ubuntu Server

   with celery, indexer and daemon scripts: https://gist.github.com/4546398

Installing Kallithea from Python Package Index (PyPI)

-----------------------------------------------------

**Kallithea** can be installed from PyPI with::

    pip install kallithea

Installation in virtualenv

--------------------------

It is highly recommended to use a separate virtualenv_ for installing Kallithea.

This way, all libraries required by Kallithea will be installed separately from your

main Python installation and things will be less problematic when upgrading the

system or Kallithea.

An additional benefit of virtualenv_ is that it doesn't require root privileges. 

- Assuming you have installed virtualenv_, create a new virtual environment

  using virtualenv command::

    virtualenv /srv/kallithea/venv

.. note:: Older versions of virtualenv required ``--no-site-packages`` to work

   correctly. It should no longer be necessary.

- this will install new virtualenv_ into `/srv/kallithea/venv`.

- Activate the virtualenv_ in your current shell session by running::

    source /srv/kallithea/venv/bin/activate

.. note:: If you're using UNIX, *do not* use ``sudo`` to run the

   ``virtualenv`` script.  It's perfectly acceptable (and desirable)

   to create a virtualenv as a normal user.

- Make a folder for Kallithea data files, and configuration somewhere on the

  filesystem. For example::

    mkdir /srv/kallithea

- Go into the created directory run this command to install kallithea::

    pip install kallithea

  Alternatively, download a .tar.gz from http://pypi.python.org/pypi/Kallithea,

  extract it and run::

    python setup.py install

- This will install Kallithea together with pylons and all other required

  python libraries into the activated virtualenv.

Requirements for Celery (optional)

----------------------------------

In order to gain maximum performance

there are some third-party you must install. When Kallithea is used

together with celery you have to install some kind of message broker,

recommended one is rabbitmq_ to make the async tasks work.

Of course Kallithea works in sync mode also and then you do not have to install

any third party applications. However, using Celery_ will give you a large

speed improvement when using many big repositories. If you plan to use

Kallithea for say 7 to 10 repositories, Kallithea will perform perfectly well

without celery running.

If you make the decision to run Kallithea with celery make sure you run

celeryd using paster and message broker together with the application.

.. note::

   Installing message broker and using celery is optional, Kallithea will

   work perfectly fine without them.

**Message Broker**

- preferred is `RabbitMq <http://www.rabbitmq.com/>`_

- A possible alternative is `Redis <http://code.google.com/p/redis/>`_

For installation instructions you can visit:

http://ask.github.com/celery/getting-started/index.html.

This is a very nice tutorial on how to start using celery_ with rabbitmq_

Next

----

You can now proceed to :ref:`setup`.

Upgrading Kallithea from Python Package Index (PyPI)

-----------------------------------------------------

.. note::

   Firstly, it is recommended that you **always** perform a database and

   configuration backup before doing an upgrade.

   (These directions will use '{version}' to note that this is the version of

   Kallithea that these files were used with.  If backing up your Kallithea

   instance from version 0.1 to 0.2, the ``my.ini`` file could be

   backed up to ``my.ini.0-1``.)

then make a copy of the database file::

 service kallithea stop

 cp kallithea.db kallithea.db.{version}

Back up your configuration file::

 cp my.ini my.ini.{version}

Ensure that you are using the Python Virtual Environment that you'd originally

installed Kallithea in::

 pip freeze

will list all packages installed in the current environment.  If Kallithea

isn't listed, change virtual environments to your venv location::

 source /srv/kallithea/venv/bin/activate

Once you have verified the environment you can upgrade Kallithea with::

 pip install --upgrade kallithea

Then run the following command from the installation directory::

 paster make-config Kallithea my.ini

This will display any changes made by the new version of Kallithea to your

current configuration. It will try to perform an automerge. It's recommended

that you re-check the content after the automerge.

.. note::

   Please always make sure your .ini files are up to date. Often errors are

   caused by missing params added in new versions.

It is also recommended that you rebuild the whoosh index after upgrading since

the new whoosh version could introduce some incompatible index changes. Please

read the changelog to see if there were any changes to whoosh.

The final step is to upgrade the database. To do this simply run::

 paster upgrade-db my.ini

This will upgrade the schema and update some of the defaults in the database,

and will always recheck the settings of the application, if there are no new

options that need to be set.

.. note::

   DB schema upgrade library has some limitations and can sometimes fail if you try to

   upgrade from older major releases. In such case simply run upgrades sequentially, eg.

   upgrading from 0.1.X to 0.3.X should be done like that: 0.1.X. > 0.2.X > 0.3.X

   You can always specify what version of Kallithea you want to install for example in pip

   `pip install Kallithea==0.2`

You may find it helpful to clear out your log file so that new errors are

readily apparent::

 echo > kallithea.log

Once that is complete, you may now start your upgraded Kallithea Instance::

 service kallithea start

Or::

 paster serve /srv/kallithea/my.ini

.. note::

   If you're using Celery, make sure you restart all instances of it after

   upgrade.

.. _virtualenv: http://pypi.python.org/pypi/virtualenv

.. _python: http://www.python.org/

.. _mercurial: http://mercurial.selenic.com/

.. _celery: http://celeryproject.org/

.. _rabbitmq: http://www.rabbitmq.com/

.. _setup:

=====

Setup

=====

Setting up Kallithea

--------------------

First, you will need to create a Kallithea configuration file. Run the

following command to do this::

    paster make-config Kallithea my.ini

- This will create the file `my.ini` in the current directory. This

  configuration file contains the various settings for Kallithea, e.g proxy

  port, email settings, usage of static files, cache, celery settings and

  logging.

Next, you need to create the databases used by Kallithea. It is recommended to

configuration file to use this other database. Kallithea currently supports

the following command::

    paster setup-db my.ini

This will prompt you for a "root" path. This "root" path is the location where

Kallithea will store all of its repositories on the current machine. After

entering this "root" path ``setup-db`` will also prompt you for a username

and password for the initial admin account which ``setup-db`` sets

up for you.

setup process can be fully automated, example for lazy::

    paster setup-db my.ini --user=nn --password=secret --email=nn@your.kallithea.server --repos=/srv/repos

- The ``setup-db`` command will create all of the needed tables and an

  admin account. When choosing a root path you can either use a new empty

  location, or a location which already contains existing repositories. If you

  (Note: make sure you specify the correct path to the root).

  for the application. It's very important since the Kallithea web interface

  will work without write access, but when trying to do a push it will

  eventually fail with permission denied errors unless it has write access.

You are now ready to use Kallithea, to run it simply execute::

    paster serve my.ini

- This command runs the Kallithea server. The web app should be available at the

  127.0.0.1:5000. This ip and port is configurable via the my.ini

  file created in previous step

- Use the admin account you created above when running ``setup-db``

  to login to the web app.

- The default permissions on each repository is read, and the owner is admin.

  Remember to update these if needed.

- In the admin panel you can toggle LDAP, anonymous, permissions settings. As

  well as edit more advanced options on users and repositories

Optionally users can create `rcextensions` package that extends Kallithea

functionality. To do this simply execute::

    paster make-rcext my.ini

This will create `rcextensions` package in the same place that your `ini` file

lives. With `rcextensions` it's possible to add additional mapping for whoosh,

stats and add additional code into the push/pull/create/delete repo hooks.

Please see the `__init__.py` file inside `rcextensions` package

for more details.

Using Kallithea with SSH

------------------------

Kallithea currently only hosts repositories using http and https. (The addition

of ssh hosting is a planned future feature.) However you can easily use ssh in

parallel with Kallithea. (Repository access via ssh is a standard "out of

repositories that Kallithea is hosting. See PublishingRepositories_)

Kallithea repository structures are kept in directories with the same name

as the project. When using repository groups, each group is a subdirectory.

This allows you to easily use ssh for accessing repositories.

In order to use ssh you need to make sure that your web-server and the users

login accounts have the correct permissions set on the appropriate directories.

(Note that these permissions are independent of any permissions you have set up

using the Kallithea web interface.)

If your main directory (the same as set in Kallithea settings) is for example

set to **/srv/repos** and the repository you are using is named `kallithea`, then

to clone via ssh you should run::

    hg clone ssh://user@server.com//srv/repos/kallithea

Using other external tools such as mercurial-server_ or using ssh key based

authentication is fully supported.

Note: In an advanced setup, in order for your ssh access to use the same

permissions as set up via the Kallithea web interface, you can create an

authentication hook to connect to the Kallithea db and runs check functions for

permissions against that.

Setting up Whoosh full text search

----------------------------------

The whoosh index can be build by using the paster

command ``make-index``. To use ``make-index`` you must specify the configuration

file that stores the location of the index. You may specify the location of the

repositories (`--repo-location`).  If not specified, this value is retrieved

from the Kallithea database.

It is also possible to specify a comma separated list of

repositories (`--index-only`) to build index only on chooses repositories

skipping any other found in repos location

You may optionally pass the option `-f` to enable a full index rebuild. Without

the `-f` option, indexing will run always in "incremental" mode.

For an incremental index build use::

    paster make-index my.ini

For a full index rebuild use::

    paster make-index my.ini -f

building index just for chosen repositories is possible with such command::

    paster make-index my.ini --index-only=vcs,kallithea

In order to do periodical index builds and keep your index always up to date.

It's recommended to do a crontab entry for incremental indexing.

An example entry might look like this::

    /path/to/python/bin/paster make-index /path/to/kallithea/my.ini

When using incremental mode (the default) whoosh will check the last

modification date of each file and add it to be reindexed if a newer file is

available. The indexing daemon checks for any removed files and removes them

from index.

If you want to rebuild index from scratch, you can use the `-f` flag as above,

or in the admin panel you can check `build from scratch` flag.

Setting up LDAP support

-----------------------

Kallithea supports LDAP authentication. In order

to use LDAP, you have to install the python-ldap_ package. This package is

available via pypi, so you can install it by running

    pip install python-ldap

.. note::

   python-ldap requires some certain libs on your system, so before installing

   it check that you have at least `openldap`, and `sasl` libraries.

LDAP settings are located in Admin->LDAP section.

Here's a typical LDAP setup::

 Connection settings

 Enable LDAP          = checked

 Host                 = host.example.org

 Port                 = 389

 Account              = <account>

 Password             = <password>

 Connection Security  = LDAPS connection

 Certificate Checks   = DEMAND

 Search settings

 Base DN              = CN=users,DC=host,DC=example,DC=org

 LDAP Filter          = (&(objectClass=user)(!(objectClass=computer)))

 LDAP Search Scope    = SUBTREE

 Attribute mappings

 Login Attribute      = uid

 First Name Attribute = firstName

 Last Name Attribute  = lastName

 E-mail Attribute     = mail

If your user groups are placed in a Organisation Unit (OU) structure the Search Settings configuration differs::

 Search settings

 Base DN              = DC=host,DC=example,DC=org

 LDAP Filter          = (&(memberOf=CN=your user group,OU=subunit,OU=unit,DC=host,DC=example,DC=org)(objectClass=user))

 LDAP Search Scope    = SUBTREE

.. _enable_ldap:

Enable LDAP : required

    Whether to use LDAP for authenticating users.

.. _ldap_host:

Host : required

    LDAP server hostname or IP address. Can be also a comma separated

    list of servers to support LDAP fail-over.

.. _Port:

Port : required

    389 for un-encrypted LDAP, 636 for SSL-encrypted LDAP.

.. _ldap_account:

Account : optional

    Only required if the LDAP server does not allow anonymous browsing of

    records.  This should be a special account for record browsing.  This

    will require `LDAP Password`_ below.

.. _LDAP Password:

Password : optional

    Only required if the LDAP server does not allow anonymous browsing of

    records.

.. _Enable LDAPS:

Connection Security : required

    Defines the connection to LDAP server

    No encryption

        Plain non encrypted connection

    LDAPS connection

        Enable LDAPS connections. It will likely require `Port`_ to be set to

        a different value (standard LDAPS port is 636). When LDAPS is enabled

        then `Certificate Checks`_ is required.

    START_TLS on LDAP connection

        START TLS connection

.. _Certificate Checks:

Certificate Checks : optional

    How SSL certificates verification is handled - this is only useful when

    `Enable LDAPS`_ is enabled.  Only DEMAND or HARD offer full SSL security

    while the other options are susceptible to man-in-the-middle attacks.  SSL

    certificates can be installed to /etc/openldap/cacerts so that the

    DEMAND or HARD options can be used with self-signed certificates or

    certificates that do not have traceable certificates of authority.

    NEVER

        A serve certificate will never be requested or checked.

    ALLOW

        A server certificate is requested.  Failure to provide a

        certificate or providing a bad certificate will not terminate the

        session.

    TRY

        A server certificate is requested.  Failure to provide a

        certificate does not halt the session; providing a bad certificate

        halts the session.

    DEMAND

        A server certificate is requested and must be provided and

        authenticated for the session to proceed.

    HARD

        The same as DEMAND.

.. _Base DN:

Base DN : required

    The Distinguished Name (DN) where searches for users will be performed.

        Only allows searching of `Base DN`_ and is usually not what you

        want.

    ONELEVEL

        Searches all entries under `Base DN`_, but not Base DN itself.

    SUBTREE

        Searches all entries below `Base DN`_, but not Base DN itself.

        When using SUBTREE `LDAP Filter`_ is useful to limit object

        location.

.. _Login Attribute:

Login Attribute : required

    The LDAP record attribute that will be matched as the USERNAME or

    ACCOUNT used to connect to Kallithea.  This will be added to `LDAP

    Filter`_ for locating the User object.  If `LDAP Filter`_ is specified as

    "LDAPFILTER", `Login Attribute`_ is specified as "uid" and the user has

    connected as "jsmith" then the `LDAP Filter`_ will be augmented as below

    ::

        (&(LDAPFILTER)(uid=jsmith))

.. _ldap_attr_firstname:

First Name Attribute : required

    The LDAP record attribute which represents the user's first name.

.. _ldap_attr_lastname:

Last Name Attribute : required

    The LDAP record attribute which represents the user's last name.

.. _ldap_attr_email:

Email Attribute : required

    The LDAP record attribute which represents the user's email address.

If all data are entered correctly, and python-ldap_ is properly installed

users should be granted access to Kallithea with LDAP accounts.  At this

time user information is copied from LDAP into the Kallithea user database.

This means that updates of an LDAP user object may not be reflected as a

user update in Kallithea.

If You have problems with LDAP access and believe You entered correct

information check out the Kallithea logs, any error messages sent from LDAP

will be saved there.

Active Directory

''''''''''''''''

Kallithea can use Microsoft Active Directory for user authentication.  This

is done through an LDAP or LDAPS connection to Active Directory.  The

following LDAP configuration settings are typical for using Active

Directory ::

 Base DN              = OU=SBSUsers,OU=Users,OU=MyBusiness,DC=v3sys,DC=local

 Login Attribute      = sAMAccountName

 First Name Attribute = givenName

 Last Name Attribute  = sn

 E-mail Attribute     = mail

All other LDAP settings will likely be site-specific and should be

appropriately configured.

Authentication by container or reverse-proxy

--------------------------------------------

Kallithea supports delegating the authentication

of users to its WSGI container, or to a reverse-proxy server through which all

clients access the application.

When these authentication methods are enabled in Kallithea, it uses the

username that the container/proxy (Apache/Nginx/etc) authenticated and doesn't

perform the authentication itself. The authorization, however, is still done by

Kallithea according to its settings.

When a user logs in for the first time using these authentication methods,

a matching user account is created in Kallithea with default permissions. An

administrator can then modify it using Kallithea's admin interface.

It's also possible for an administrator to create accounts and configure their

permissions before the user logs in for the first time.

Container-based authentication

''''''''''''''''''''''''''''''

In a container-based authentication setup, Kallithea reads the user name from

the ``REMOTE_USER`` server variable provided by the WSGI container.

After setting up your container (see `Apache's WSGI config`_), you'd need

to configure it to require authentication on the location configured for

Kallithea.

Proxy pass-through authentication

'''''''''''''''''''''''''''''''''

In a proxy pass-through authentication setup, Kallithea reads the user name

from the ``X-Forwarded-User`` request header, which should be configured to be

sent by the reverse-proxy server.

After setting up your proxy solution (see `Apache virtual host reverse proxy example`_,

`Apache as subdirectory`_ or `Nginx virtual host example`_), you'd need to

configure the authentication and add the username in a request header named

``X-Forwarded-User``.

For example, the following config section for Apache sets a subdirectory in a

reverse-proxy setup with basic auth::

    <Location /<someprefix> >

      ProxyPass http://127.0.0.1:5000/<someprefix>

      ProxyPassReverse http://127.0.0.1:5000/<someprefix>

      SetEnvIf X-Url-Scheme https HTTPS=1

      AuthType Basic

      AuthName "Kallithea authentication"

      AuthUserFile /srv/kallithea/.htpasswd

      require valid-user

      RequestHeader unset X-Forwarded-User

      RewriteEngine On

      RewriteCond %{LA-U:REMOTE_USER} (.+)

      RewriteRule .* - [E=RU:%1]

      RequestHeader set X-Forwarded-User %{RU}e

    </Location>

.. note::

   If you enable proxy pass-through authentication, make sure your server is

   only accessible through the proxy. Otherwise, any client would be able to

   forge the authentication header and could effectively become authenticated

   using any account of their liking.

Integration with Issue trackers

-------------------------------

Kallithea provides a simple integration with issue trackers. It's possible

to define a regular expression that will fetch issue id stored in commit

messages and replace that with an url to this issue. To enable this simply

uncomment following variables in the ini file::

    issue_pat = (?:^#|\s#)(\w+)

    issue_server_link = https://myissueserver.com/{repo}/issue/{id}

    issue_prefix = #

`issue_pat` is the regular expression describing which strings in

commit messages will be treated as issue references. A match group in

parentheses should be used to specify the actual issue id.

The default expression matches issues in the format '#<number>', e.g. '#300'.

Matched issues are replaced with the link specified as `issue_server_link`

{id} is replaced with issue id, and {repo} with repository name.

Since the # is stripped away, `issue_prefix` is prepended to the link text.

`issue_prefix` doesn't necessarily need to be #: if you set issue

prefix to ISSUE- this will generate a URL in format::

  <a href="https://myissueserver.com/example_repo/issue/300">ISSUE-300</a>

If needed, more than one pattern can be specified by appending a unique suffix to

the variables. For example::

    issue_pat_wiki = (?:wiki-)(.+)

    issue_server_link_wiki = https://mywiki.com/{id}

    issue_prefix_wiki = WIKI-

With these settings, wiki pages can be referenced as wiki-some-id, and every

such reference will be transformed into::

  <a href="https://mywiki.com/some-id">WIKI-some-id</a>

Hook management

---------------

Hooks can be managed in similar way to this used in .hgrc files.

To access hooks setting click `advanced setup` on Hooks section of Mercurial

Settings in Admin.

There are 4 built in hooks that cannot be changed (only enable/disable by

checkboxes on previos section).

To add another custom hook simply fill in first section with

<name>.<hook_type> and the second one with hook path. Example hooks

can be found at *kallithea.lib.hooks*.

Changing default encoding

-------------------------

It is configurable as `default_encoding` in the .ini file.

This affects many parts in Kallithea including user names, filenames, and

encoding of commit messages. In addition Kallithea can detect if `chardet`

library is installed. If `chardet` is detected Kallithea will fallback to it

when there are encode/decode errors.

Celery configuration

--------------------

Celery is configured in the Kallithea ini configuration files.

Simply set use_celery=true in the ini file then add / change the configuration

variables inside the ini file.

Remember that the ini files use the format with '.' not with '_' like celery.

So for example setting `BROKER_HOST` in celery means setting `broker.host` in

the config file.

In order to start using celery run::

 paster celeryd <configfile.ini>