docs: clarify the need for having 'npm' and 'node' available in $PATH

docs/installation.rst

@@ -1,150 +1,154 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
         pip install --upgrade pip setuptools
         pip install --upgrade -e .
         python3 setup.py compile_catalog   # for translation of the UI
 
 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.
 
 - Assuming you have installed virtualenv, create a new virtual environment
   for example, in `/srv/kallithea/venv`, using the venv command::
 
     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 ``virtualenv`` script; it
    will "activate" a shell that terminates immediately. It is also 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 and run this command to install Kallithea::
 
     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 must be prepared. This requires ``npm`` version 6
-or later, which needs ``node.js`` (version 12 or later). Prepare the front-end
-by running::
+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

@@ -1,236 +1,236 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`` tooling so
-    they can be served to the client as static 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.
 
 
 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/