docs: when using venv with a clone, recommend using 'venv' as location

Avoid having the odd inconsistent location ../kallithea-venv to care about.

For good or bad, this might change how it is feasible to grep. I usually make
sure to only search tracked files:
  grep Foo `hg mani`

.hgignore

@@ -1,54 +1,55 b''
 syntax: glob
 *.pyc
 *.swp
 *.sqlite
 *.tox
 *.egg-info
 *.egg
 *.mo
 *.orig
 *.rej
 *.bak
 .eggs/
 
 syntax: regexp
 ^rcextensions
 ^build
 ^dist/
 ^docs/build/
 ^docs/_build/
 ^data$
 ^sql_dumps/
 ^\.settings$
 ^\.project$
 ^\.pydevproject$
 ^\.coverage$
 ^kallithea/front-end/node_modules$
 ^kallithea/front-end/package-lock\.json$
 ^kallithea/front-end/theme\.less$
 ^kallithea/front-end/tmp$
 ^kallithea/public/codemirror$
 ^kallithea/public/css/select2-spinner\.gif$
 ^kallithea/public/css/select2\.png$
 ^kallithea/public/css/select2x2\.png$
 ^kallithea/public/css/style\.css$
 ^kallithea/public/css/style\.css\.map$
 ^kallithea/public/js/bootstrap\.js$
 ^kallithea/public/js/dataTables\.bootstrap\.js$
 ^kallithea/public/js/jquery\.atwho\.min\.js$
 ^kallithea/public/js/jquery\.caret\.min\.js$
 ^kallithea/public/js/jquery\.dataTables\.js$
 ^kallithea/public/js/jquery\.flot\.js$
 ^kallithea/public/js/jquery\.flot\.selection\.js$
 ^kallithea/public/js/jquery\.flot\.time\.js$
 ^kallithea/public/js/jquery\.min\.js$
 ^kallithea/public/js/select2\.js$
 ^kallithea\.db$
 ^test\.db$
 ^Kallithea\.egg-info$
 ^my\.ini$
 ^fabfile.py
 ^\.idea$
 ^\.cache$
 ^\.pytest_cache$
+^venv$
 /__pycache__$

docs/contributing.rst

@@ -1,337 +1,337 b''
 .. _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 on Our Own Kallithea (aka OOK) at
 https://kallithea-scm.org/repos/kallithea/, our self-hosted instance
 of Kallithea.
 
 For now, we use Bitbucket_ for `pull requests`_ and `issue tracking`_. The
 issue tracker is for tracking bugs, not for support, discussion, or ideas --
 please use the `mailing list`_ or :ref:`IRC <readme>` 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. See :ref:`translations`
 for more details.
 
 
 Getting started
 ---------------
 
 To get started with Kallithea development run the following commands in your
 bash shell::
 
         hg clone https://kallithea-scm.org/repos/kallithea
         cd kallithea
-        python3 -m venv ../kallithea-venv
-        . ../kallithea-venv/bin/activate
+        python3 -m venv venv
+        . venv/bin/activate
         pip install --upgrade pip setuptools
         pip install --upgrade -e . -r dev_requirements.txt python-ldap python-pam
         kallithea-cli config-create my.ini
         kallithea-cli db-create -c my.ini --user=user --email=[e-mail] --password=password --repos=/tmp
         kallithea-cli front-end-build
         gearbox serve -c my.ini --reload &
         firefox http://127.0.0.1:5000/
 
 If you plan to use Bitbucket_ for sending contributions, you can also fork
 Kallithea on Bitbucket_ first (https://bitbucket.org/conservancy/kallithea) and
 then replace the clone step above by a clone of your fork. In this case, please
 see :ref:`contributing-guidelines` below for configuring your fork correctly.
 
 
 Contribution flow
 -----------------
 
 Starting from an existing Kallithea clone, make sure it is up to date with the
 latest upstream changes::
 
         hg pull
         hg update
 
 Review the :ref:`contributing-guidelines` and :ref:`coding-guidelines`.
 
 If you are new to Mercurial, refer to Mercurial `Quick Start`_ and `Beginners
 Guide`_ on the Mercurial wiki.
 
 Now, make some changes and test them (see :ref:`contributing-tests`). Don't
 forget to add new tests to cover new functionality or bug fixes.
 
 For documentation changes, run ``make html`` from the ``docs`` directory to
 generate the HTML result, then review them in your browser.
 
 Before submitting any changes, run the cleanup script::
 
         ./scripts/run-all-cleanup
 
 When you are completely ready, you can send your changes to the community for
 review and inclusion. Most commonly used methods are sending patches to the
 mailing list (via ``hg email``) or by creating a pull request on Bitbucket_.
 
 .. _contributing-tests:
 
 
 Running tests
 -------------
 
 After finishing your changes make sure all tests pass cleanly. Run the testsuite
 by invoking ``py.test`` from the project root::
 
     py.test
 
 Note that on unix systems, the temporary directory (``/tmp`` or where
 ``$TMPDIR`` points) must allow executable files; Git hooks must be executable,
 and the test suite creates repositories in the temporary directory. Linux
 systems with /tmp mounted noexec will thus fail.
 
 Tests can be run on PostgreSQL like::
 
     sudo -u postgres createuser 'kallithea-test' --pwprompt  # password password
     sudo -u postgres createdb 'kallithea-test' --owner 'kallithea-test'
     REUSE_TEST_DB='postgresql://kallithea-test:password@localhost/kallithea-test' py.test
 
 Tests can be run on MariaDB/MySQL like::
 
     echo "GRANT ALL PRIVILEGES ON \`kallithea-test\`.* TO 'kallithea-test'@'localhost' IDENTIFIED BY 'password'" | sudo -u mysql mysql
     TEST_DB='mysql://kallithea-test:password@localhost/kallithea-test?charset=utf8mb4' py.test
 
 You can also use ``tox`` to run the tests with all supported Python versions.
 
 When running tests, Kallithea generates a `test.ini` based on template values
 in `kallithea/tests/conftest.py` and populates the SQLite database specified
 there.
 
 It is possible to avoid recreating the full test database on each invocation of
 the tests, thus eliminating the initial delay. To achieve this, run the tests as::
 
     gearbox serve -c /tmp/kallithea-test-XXX/test.ini --pid-file=test.pid --daemon
     KALLITHEA_WHOOSH_TEST_DISABLE=1 KALLITHEA_NO_TMP_PATH=1 py.test
     kill -9 $(cat test.pid)
 
 In these commands, the following variables are used::
 
     KALLITHEA_WHOOSH_TEST_DISABLE=1 - skip whoosh index building and tests
     KALLITHEA_NO_TMP_PATH=1 - disable new temp path for tests, used mostly for testing_vcs_operations
 
 You can run individual tests by specifying their path as argument to py.test.
 py.test also has many more options, see `py.test -h`. Some useful options
 are::
 
     -k EXPRESSION         only run tests which match the given substring
                           expression. An expression is a python evaluable
                           expression where all names are substring-matched
                           against test names and their parent classes. Example:
     -x, --exitfirst       exit instantly on first error or failed test.
     --lf                  rerun only the tests that failed at the last run (or
                           all if none failed)
     --ff                  run all tests but run the last failures first. This
                           may re-order tests and thus lead to repeated fixture
                           setup/teardown
     --pdb                 start the interactive Python debugger on errors.
     -s, --capture=no      don't capture stdout (any stdout output will be
                           printed immediately)
 
 Performance tests
 ^^^^^^^^^^^^^^^^^
 
 A number of performance tests are present in the test suite, but they are
 not run in a standard test run. These tests are useful to
 evaluate the impact of certain code changes with respect to performance.
 
 To run these tests::
 
     env TEST_PERFORMANCE=1 py.test kallithea/tests/performance
 
 To analyze performance, you could install pytest-profiling_, which enables the
 --profile and --profile-svg options to py.test.
 
 .. _pytest-profiling: https://github.com/manahl/pytest-plugins/tree/master/pytest-profiling
 
 .. _contributing-guidelines:
 
 
 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.
 
 Contributions will be accepted in most formats -- such as pull requests on
 Bitbucket, something hosted on your own Kallithea instance, or patches sent by
 email to the `kallithea-general`_ mailing list.
 
 When contributing via Bitbucket, please make your fork of
 https://bitbucket.org/conservancy/kallithea/ `non-publishing`_ -- it is one of
 the settings on "Repository details" page. This ensures your commits are in
 "draft" phase and makes it easier for you to address feedback and for project
 maintainers to integrate your changes.
 
 .. _non-publishing: https://www.mercurial-scm.org/wiki/Phases#Publishing_Repository
 
 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.
 
 There is a main development branch ("default") which is generally stable so that
 it can be (and is) used in production. There is also a "stable" branch that is
 almost exclusively reserved for bug fixes or trivial changes. Experimental
 changes should live elsewhere (for example in a pull request) until they are
 ready.
 
 .. _coding-guidelines:
 
 
 Coding guidelines
 -----------------
 
 We don't have a formal coding/formatting standard. We are currently using a mix
 of Mercurial's (https://www.mercurial-scm.org/wiki/CodingStyle), pep8, and
 consistency with existing code. Run ``scripts/run-all-cleanup`` before
 committing to ensure some basic code formatting consistency.
 
 We support Python 3.6 and later.
 
 We try to support the most common modern web browsers. IE9 is still supported
 to the extent it is feasible, IE8 is not.
 
 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 element 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
 ``{}``.
 Variables holding jQuery objects should be named with 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.
 
 Use American English grammar and spelling overall. Use `English title case`_ for
 page titles, button labels, headers, and 'labels' for fields in forms.
 
 .. _English title case: https://en.wikipedia.org/wiki/Capitalization#Title_case
 
 Template helpers (that is, everything in ``kallithea.lib.helpers``)
 should only be referenced from templates. If you need to call a
 helper from the Python code, consider moving the function somewhere
 else (e.g. to the model).
 
 Notes on the SQLAlchemy session
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Each HTTP request runs inside an independent SQLAlchemy session (as well
 as in an independent database transaction). ``Session`` is the session manager
 and factory. ``Session()`` will create a new session on-demand or return the
 current session for the active thread. Many database operations are methods on
 such session instances. The session will generally be removed by
 TurboGears automatically.
 
 Database model objects
 (almost) always belong to a particular SQLAlchemy session, which means
 that SQLAlchemy will ensure that they're kept in sync with the database
 (but also means that they cannot be shared across requests).
 
 Objects can be added to the session using ``Session().add``, but this is
 rarely needed:
 
 * When creating a database object by calling the constructor directly,
   it must explicitly be added to the session.
 
 * When creating an object using a factory function (like
   ``create_repo``), the returned object has already (by convention)
   been added to the session, and should not be added again.
 
 * When getting an object from the session (via ``Session().query`` or
   any of the utility functions that look up objects in the database),
   it's already part of the session, and should not be added again.
   SQLAlchemy monitors attribute modifications automatically for all
   objects it knows about and syncs them to the database.
 
 SQLAlchemy also flushes changes to the database automatically; manually
 calling ``Session().flush`` is usually only necessary when the Python
 code needs the database to assign an "auto-increment" primary key ID to
 a freshly created model object (before flushing, the ID attribute will
 be ``None``).
 
 Debugging
 ^^^^^^^^^
 
 A good way to trace what Kallithea is doing is to keep an eye on the output on
 stdout/stderr of the server process. Perhaps change ``my.ini`` to log at
 ``DEBUG`` or ``INFO`` level, especially ``[logger_kallithea]``, but perhaps
 also other loggers. It is often easier to add additional ``log`` or ``print``
 statements than to use a Python debugger.
 
 Sometimes it is simpler to disable ``errorpage.enabled`` and perhaps also
 ``trace_errors.enable`` to expose raw errors instead of adding extra
 processing. Enabling ``debug`` can be helpful for showing and exploring
 tracebacks in the browser, but is also insecure and will add extra processing.
 
 TurboGears2 DebugBar
 ^^^^^^^^^^^^^^^^^^^^
 
 It is possible to enable the TurboGears2-provided DebugBar_, a toolbar overlayed
 over the Kallithea web interface, allowing you to see:
 
 * timing information of the current request, including profiling information
 * request data, including GET data, POST data, cookies, headers and environment
   variables
 * a list of executed database queries, including timing and result values
 
 DebugBar is only activated when ``debug = true`` is set in the configuration
 file. This is important, because the DebugBar toolbar will be visible for all
 users, and allow them to see information they should not be allowed to see. Like
 is anyway the case for ``debug = true``, do not use this in production!
 
 To enable DebugBar, install ``tgext.debugbar`` and ``kajiki`` (typically via
 ``pip``) and restart Kallithea (in debug mode).
 
 
 "Roadmap"
 ---------
 
 We do not have a road map but are waiting for your contributions. Refer to the
 wiki_ for some ideas of places we might want to go -- contributions in these
 areas are very welcome.
 
 
 Thank you for your contribution!
 --------------------------------
 
 
 .. _Weblate: http://weblate.org/
 .. _issue tracking: 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
 .. _kallithea-general: http://lists.sfconservancy.org/mailman/listinfo/kallithea-general
 .. _Hosted Weblate: https://hosted.weblate.org/projects/kallithea/kallithea/
 .. _wiki: https://bitbucket.org/conservancy/kallithea/wiki/Home
 .. _DebugBar: https://github.com/TurboGears/tgext.debugbar
 .. _Quick Start: https://www.mercurial-scm.org/wiki/QuickStart
 .. _Beginners Guide: https://www.mercurial-scm.org/wiki/BeginnersGuides

docs/installation.rst

@@ -1,157 +1,159 b''
 .. _installation:
 
 ==========================
 Installation on Unix/Linux
 ==========================
 
 The following describes three different ways of installing Kallithea:
 
 - :ref:`installation-source`: The simplest way to keep the installation
   up-to-date and track any local customizations is to run directly from
   source in a Kallithea repository clone, preferably inside a virtualenv
   virtual Python environment.
 
 - :ref:`installation-virtualenv`: If you prefer to only use released versions
   of Kallithea, the recommended method is to install Kallithea in a virtual
   Python environment using `virtualenv`. The advantages of this method over
   direct installation is that Kallithea and its dependencies are completely
   contained inside the virtualenv (which also means you can have multiple
   installations side by side or remove it entirely by just removing the
   virtualenv directory) and does not require root privileges.
 
 - :ref:`installation-without-virtualenv`: The alternative method of installing
   a Kallithea release is using standard pip. The package will be installed in
   the same location as all other Python packages you have ever installed. As a
   result, removing it is not as straightforward as with a virtualenv, as you'd
   have to remove its dependencies manually and make sure that they are not
   needed by other packages.
 
 Regardless of the installation method you may need to make sure you have
 appropriate development packages installed, as installation of some of the
 Kallithea dependencies requires a working C compiler and libffi library
 headers. Depending on your configuration, you may also need to install
 Git and development packages for the database of your choice.
 
 For Debian and Ubuntu, the following command will ensure that a reasonable
 set of dependencies is installed::
 
     sudo apt-get install build-essential git libffi-dev python3-dev
 
 For Fedora and RHEL-derivatives, the following command will ensure that a
 reasonable set of dependencies is installed::
 
     sudo yum install gcc git libffi-devel python3-devel
 
 .. _installation-source:
 
 
 Installation from repository source
 -----------------------------------
 
 To install Kallithea in a virtualenv using the stable branch of the development
 repository, use the following commands in your bash shell::
 
         hg clone https://kallithea-scm.org/repos/kallithea -u stable
         cd kallithea
-        python3 -m venv ../kallithea-venv
-        . ../kallithea-venv/bin/activate
+        python3 -m venv venv
+        . venv/bin/activate
         pip install --upgrade pip setuptools
         pip install --upgrade -e .
         python3 setup.py compile_catalog   # for translation of the UI
 
 .. note::
    This will install all Python dependencies into the virtualenv. Kallithea
    itself will however only be installed as a pointer to the source location.
    The source clone must thus be kept in the same location, and it shouldn't be
    updated to other revisions unless you want to upgrade. Edits in the source
    tree will have immediate impact (possibly after a restart of the service).
 
 You can now proceed to :ref:`install-front-end`.
 
 .. _installation-virtualenv:
 
 
 Installing a released version in a 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 other applications 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.
 
 - Don't install as root - install as a dedicated user like ``kallithea``.
+  If necessary, create the top directory for the virtualenv (like
+  ``/srv/kallithea/venv``) as root and assign ownership to the user.
 
 - Create a new virtual environment, for example in ``/srv/kallithea/venv``,
   specifying the right Python binary::
 
     python3 -m venv /srv/kallithea/venv
 
 - Activate the virtualenv in your current shell session and make sure the
   basic requirements are up-to-date by running the following commands in your
   bash shell::
 
     . /srv/kallithea/venv/bin/activate
     pip install --upgrade pip setuptools
 
 .. note:: You can't use UNIX ``sudo`` to source the ``activate`` script; it
    will "activate" a shell that terminates immediately.
 
 - Install Kallithea in the activated virtualenv::
 
     pip install --upgrade kallithea
 
 .. note:: Some dependencies are optional. If you need them, install them in
    the virtualenv too::
 
      pip install --upgrade kallithea python-ldap python-pam psycopg2
 
    This might require installation of development packages using your
    distribution's package manager.
 
    Alternatively, download a .tar.gz from http://pypi.python.org/pypi/Kallithea,
    extract it and install from source by running::
 
      pip install --upgrade .
 
 - This will install Kallithea together with all other required
   Python libraries into the activated virtualenv.
 
 You can now proceed to :ref:`install-front-end`.
 
 .. _installation-without-virtualenv:
 
 
 Installing a released version without virtualenv
 ------------------------------------------------
 
 For installation without virtualenv, 'just' use::
 
     pip install kallithea
 
 Note that this method requires root privileges and will install packages
 globally without using the system's package manager.
 
 To install as a regular user in ``~/.local``, you can use::
 
     pip install --user kallithea
 
 You can now proceed to :ref:`install-front-end`.
 
 .. _install-front-end:
 
 
 Prepare front-end files
 -----------------------
 
 Finally, the front-end files with CSS and JavaScript must be prepared. This
 depends on having some commands available in the shell search path: ``npm``
 version 6 or later, and ``node.js`` (version 12 or later) available as
 ``node``. The installation method for these dependencies varies between
 operating systems and distributions.
 
 Prepare the front-end by running::
 
     kallithea-cli front-end-build
 
 You can now proceed to :ref:`setup`.

docs/overview.rst

@@ -1,270 +1,270 b''
 .. _overview:
 
 =====================
 Installation overview
 =====================
 
 Some overview and some details that can help understanding the options when
 installing Kallithea.
 
 1. **Prepare environment and external dependencies.**
     Kallithea needs:
 
     * A filesystem where the Mercurial and Git repositories can be stored.
     * A database where meta data can be stored.
     * A Python environment where the Kallithea application and its dependencies
       can be installed.
     * A web server that can host the Kallithea web application using the WSGI
       API.
 
 2. **Install Kallithea software.**
     This makes the ``kallithea-cli`` command line tool available.
 
 3. **Prepare front-end files**
     Some front-end files must be fetched or created using ``npm`` and ``node``
     tooling so they can be served to the client as static files.
 
 4. **Create low level configuration file.**
     Use ``kallithea-cli config-create`` to create a ``.ini`` file with database
     connection info, mail server information, configuration for the specified
     web server, etc.
 
 5. **Populate the database.**
     Use ``kallithea-cli db-create`` with the ``.ini`` file to create the
     database schema and insert the most basic information: the location of the
     repository store and an initial local admin user.
 
 6. **Configure the web server.**
     The web server must invoke the WSGI entrypoint for the Kallithea software
     using the ``.ini`` file (and thus the database). This makes the web
     application available so the local admin user can log in and tweak the
     configuration further.
 
 7. **Configure users.**
     The initial admin user can create additional local users, or configure how
     users can be created and authenticated from other user directories.
 
 See the subsequent sections, the separate OS-specific instructions, and
 :ref:`setup` for details on these steps.
 
 
 File system location
 --------------------
 
 Kallithea can be installed in many different ways. The main parts are:
 
 - A location for the Kallithea software and its dependencies. This includes
   the Python code, template files, and front-end code. After installation, this
   will be read-only (except when upgrading).
 
 - A location for the ``.ini`` configuration file that tells the Kallithea
   instance which database to use (and thus also the repository location).
   After installation, this will be read-only (except when upgrading).
 
 - A location for various data files and caches for the Kallithea instance. This
   is by default in a ``data`` directory next to the ``.ini`` file. This will
   have to be writable by the running Kallithea service.
 
 - A database. The ``.ini`` file specifies which database to use. The database
   will be a separate service and live elsewhere in the filesystem if using
   PostgreSQL or MariaDB/MySQL. If using SQLite, it will by default live next to
   the ``.ini`` file, as ``kallithea.db``.
 
 - A location for the repositories that are hosted by this Kallithea instance.
   This will have to be writable by the running Kallithea service. The path to
   this location will be configured in the database.
 
 For simple setups, it is fine to just use something like a ``kallithea`` user
 with home in ``/home/kallithea`` and place everything there.
 
 For experiments, it might be convenient to run everything as yourself and work
 inside a clone of Kallithea, with the ``.ini`` and SQLite database in the root
-of the clone.
+of the clone, and a virtualenv in ``venv``.
 
 
 Python environment
 ------------------
 
 **Kallithea** is written entirely in Python_ and requires Python version
 3.6 or higher.
 
 Given a Python installation, there are different ways of providing the
 environment for running Python applications. Each of them pretty much
 corresponds to a ``site-packages`` directory somewhere where packages can be
 installed.
 
 Kallithea itself can be run from source or be installed, but even when running
 from source, there are some dependencies that must be installed in the Python
 environment used for running Kallithea.
 
 - Packages *could* be installed in Python's ``site-packages`` directory ... but
   that would require running pip_ as root and it would be hard to uninstall or
   upgrade and is probably not a good idea unless using a package manager.
 
 - Packages could also be installed in ``~/.local`` ... but that is probably
   only a good idea if using a dedicated user per application or instance.
 
 - Finally, it can be installed in a virtualenv. That is a very lightweight
   "container" where each Kallithea instance can get its own dedicated and
   self-contained virtual environment.
 
 We recommend using virtualenv for installing Kallithea.
 
 
 Locale environment
 ------------------
 
 In order to ensure a correct functioning of Kallithea with respect to non-ASCII
 characters in user names, file paths, commit messages, etc., it is very
 important that Kallithea is run with a correct `locale` configuration.
 
 On Unix, environment variables like ``LANG`` or ``LC_ALL`` can specify a language (like
 ``en_US``) and encoding (like ``UTF-8``) to use for code points outside the ASCII
 range. The flexibility of supporting multiple encodings of Unicode has the flip
 side of having to specify which encoding to use - especially for Mercurial.
 
 It depends on the OS distribution and system configuration which locales are
 available. For example, some Docker containers based on Debian default to only
 supporting the ``C`` language, while other Linux environments have ``en_US`` but not
 ``C``. The ``locale -a`` command will show which values are available on the
 current system. Regardless of the actual language, you should normally choose a
 locale that has the ``UTF-8`` encoding (note that spellings ``utf8``, ``utf-8``,
 ``UTF8``, ``UTF-8`` are all referring to the same thing)
 
 For technical reasons, the locale configuration **must** be provided in the
 environment in which Kallithea runs - it cannot be specified in the ``.ini`` file.
 How to practically do this depends on the web server that is used and the way it
 is started. For example, gearbox is often started by a normal user, either
 manually or via a script. In this case, the required locale environment
 variables can be provided directly in that user's environment or in the script.
 However, web servers like Apache are often started at boot via an init script or
 service file. Modifying the environment for this case would thus require
 root/administrator privileges. Moreover, that environment would dictate the
 settings for all web services running under that web server, Kallithea being
 just one of them. Specifically in the case of Apache with ``mod_wsgi``, the
 locale can be set for a specific service in its ``WSGIDaemonProcess`` directive,
 using the ``lang`` parameter.
 
 
 Installation methods
 --------------------
 
 Kallithea must be installed on a server. Kallithea is installed in a Python
 environment so it can use packages that are installed there and make itself
 available for other packages.
 
 Two different cases will pretty much cover the options for how it can be
 installed.
 
 - The Kallithea source repository can be cloned and used -- it is kept stable and
   can be used in production. The Kallithea maintainers use the development
   branch in production. The advantage of installation from source and regularly
   updating it is that you take advantage of the most recent improvements. Using
   it directly from a DVCS also means that it is easy to track local customizations.
 
   Running ``pip install -e .`` in the source will use pip to install the
   necessary dependencies in the Python environment and create a
   ``.../site-packages/Kallithea.egg-link`` file there that points at the Kallithea
   source.
 
 - Kallithea can also be installed from ready-made packages using a package manager.
   The official released versions are available on PyPI_ and can be downloaded and
   installed with all dependencies using ``pip install kallithea``.
 
   With this method, Kallithea is installed in the Python environment as any
   other package, usually as a ``.../site-packages/Kallithea-X-py3.8.egg/``
   directory with Python files and everything else that is needed.
 
   (``pip install kallithea`` from a source tree will do pretty much the same
   but build the Kallithea package itself locally instead of downloading it.)
 
 .. note::
    Kallithea includes front-end code that needs to be processed to prepare
    static files that can be served at run time and used on the client side. The
    tool npm_ is used to download external dependencies and orchestrate the
    processing. The ``npm`` binary must thus be available at install time but is
    not used at run time.
 
 
 Web server
 ----------
 
 Kallithea is (primarily) a WSGI_ application that must be run from a web
 server that serves WSGI applications over HTTP.
 
 Kallithea itself is not serving HTTP (or HTTPS); that is the web server's
 responsibility. Kallithea does however need to know its own user facing URL
 (protocol, address, port and path) for each HTTP request. Kallithea will
 usually use its own HTML/cookie based authentication but can also be configured
 to use web server authentication.
 
 There are several web server options:
 
 - Kallithea uses the Gearbox_ tool as command line interface. Gearbox provides
   ``gearbox serve`` as a convenient way to launch a Python WSGI / web server
   from the command line. That is perfect for development and evaluation.
   Actual use in production might have different requirements and need extra
   work to make it manageable as a scalable system service.
 
   Gearbox comes with its own built-in web server for development but Kallithea
   defaults to using Waitress_. Gunicorn_ and Gevent_ are also options. These
   web servers have different limited feature sets.
 
   The web server used by ``gearbox serve`` is configured in the ``.ini`` file.
   Create it with ``config-create`` using for example ``http_server=waitress``
   to get a configuration starting point for your choice of web server.
 
   (Gearbox will do like ``paste`` and use the WSGI application entry point
   ``kallithea.config.application:make_app`` as specified in ``setup.py``.)
 
 - `Apache httpd`_ can serve WSGI applications directly using mod_wsgi_ and a
   simple Python file with the necessary configuration. This is a good option if
   Apache is an option.
 
 - uWSGI_ is also a full web server with built-in WSGI module. Use
   ``config-create`` with ``http_server=uwsgi`` to get a ``.ini`` file with
   uWSGI configuration.
 
 - IIS_ can also server WSGI applications directly using isapi-wsgi_.
 
 - A `reverse HTTP proxy <https://en.wikipedia.org/wiki/Reverse_proxy>`_
   can be put in front of another web server which has WSGI support.
   Such a layered setup can be complex but might in some cases be the right
   option, for example to standardize on one internet-facing web server, to add
   encryption or special authentication or for other security reasons, to
   provide caching of static files, or to provide load balancing or fail-over.
   Nginx_, Varnish_ and HAProxy_ are often used for this purpose, often in front
   of a ``gearbox serve`` that somehow is wrapped as a service.
 
 The best option depends on what you are familiar with and the requirements for
 performance and stability. Also, keep in mind that Kallithea mainly is serving
 dynamically generated pages from a relatively slow Python process. Kallithea is
 also often used inside organizations with a limited amount of users and thus no
 continuous hammering from the internet.
 
 .. note::
    Kallithea, the libraries it uses, and Python itself do in several places use
    simple caching in memory. Caches and memory are not always released in a way
    that is suitable for long-running processes. They might appear to be leaking
    memory. The worker processes should thus regularly be restarted - for
    example after 1000 requests and/or one hour. This can usually be done by the
    web server or the tool used for running it as a system service.
 
 
 .. _Python: http://www.python.org/
 .. _Gunicorn: http://gunicorn.org/
 .. _Gevent: http://www.gevent.org/
 .. _Waitress: https://docs.pylonsproject.org/projects/waitress/
 .. _Gearbox: https://turbogears.readthedocs.io/en/latest/turbogears/gearbox.html
 .. _PyPI: https://pypi.python.org/pypi
 .. _Apache httpd: http://httpd.apache.org/
 .. _mod_wsgi: https://modwsgi.readthedocs.io/
 .. _isapi-wsgi: https://github.com/hexdump42/isapi-wsgi
 .. _uWSGI: https://uwsgi-docs.readthedocs.io/
 .. _nginx: http://nginx.org/en/
 .. _iis: http://en.wikipedia.org/wiki/Internet_Information_Services
 .. _pip: http://en.wikipedia.org/wiki/Pip_%28package_manager%29
 .. _WSGI: http://en.wikipedia.org/wiki/Web_Server_Gateway_Interface
 .. _HAProxy: http://www.haproxy.org/
 .. _Varnish: https://www.varnish-cache.org/
 .. _npm: https://www.npmjs.com/