Update existing docs and add new docs

* Updates docs about sass-watcher process in docker
* Adds docs about hacking CSS
* Adds docs on how to build CSS from Sass when building NAV from source

Author: podliashanyk

doc/hacking/hacking.rst

@@ -156,6 +156,7 @@ Directory                          Description
                                    processes.
 :file:`python/`                    Python source code.
 :file:`python/nav/etc/`            Example/initial configuration files.
+:file:`python/nav/web/sass/`       SCSS stylesheets.
 :file:`python/nav/web/static/`     Static media such as CSS stylesheets, images and JavaScript to be
                                    served by a webserver.
 :file:`python/nav/web/templates/`  Main/global Django HTML templates. More be located in individual
@@ -283,6 +284,24 @@ developing, something browsers love to do! See `config-urlArgs
 documentation for details. :file:`require_config.dev.js` is listed in the
 repository :file:`.gitignore` file.
 
+CSS
+---
+
+NAV uses Sass for styling. If you want to modify the styling,
+you can do so by editing the SCSS files in the :file:`python/nav/web/static/scss`
+directory. To build the CSS assets, you will need to have Node.js
+and npm installed. Once you have these installed, you can run
+the following command to build the CSS files::
+
+  npm install
+  npm run build:sass
+
+This will build the CSS assets and place them in the :file:`python/nav/web/static/css`
+directory. If you want to watch for changes in the SCSS files and rebuild the
+CSS assets automatically, you can run the following command instead::
+
+  npm run watch:sass
+
 
 
 Database

doc/hacking/using-docker.rst

@@ -187,9 +187,10 @@ nav
   starts.
 
 sass-watcher
-  This is a process that monitors the :file:`python/nav/web/sass/` subdirectory
-  for changes, and re-runs ``python setup.py build_sass`` (i.e. rebuilding all
-  the SASS-based stylesheets) on changes.
+  This is a process that runs ``npm run watch:sass`` command to monitor and
+  rebuild all the SASS-based stylesheets whenever changes occur
+  in the :file:`python/nav/web/sass/` subdirectory. The command continuously
+  monitors the files and does not exit by itself.
 
 The individual logs of these program are typically found inside the ``nav``
 container in the :file:`/var/log/supervisor/` directory. The NAV process logs

doc/howto/generic-install-from-source.rst

@@ -5,6 +5,8 @@
 This is a generic guide to installing NAV from source code on a \*NIX flavored
 operating system. The specifics of how to install NAV's dependencies, such as
 :xref:`PostgreSQL` or :xref:`Graphite` will be entirely up to you and your choice of OS.
+Note that building NAV from source will also require Node.js and npm to be installed
+in order to manage frontend assets.
 
 
 Dependencies
@@ -21,6 +23,11 @@ To build NAV, you need at least the following:
  * Python >= 3.9.0
  * Sphinx >= 1.0 (for building this documentation)
 
+Additionally to build frontend assets (like CSS and JS), you will need:
+
+ * Node.js >= 14.0
+ * npm >= 6.0
+
 Runtime requirements
 --------------------
 
@@ -73,6 +80,16 @@ default.
 Installing NAV
 ==============
 
+First you need to build the static assets. To do this, you will need to have
+Node.js and npm installed. Once you have these installed, you can run
+the following command to build the CSS assets::
+
+  npm install
+  npm run build:sass
+
+This will build the CSS assets and place them in the :file:`python/nav/web/static/css`
+directory.
+
 To build and install NAV and all its Python dependencies::
 
   pip install -r requirements.txt -c constraints.txt .

doc/intro/install.rst

@@ -7,7 +7,8 @@
 There are two main options for installing NAV: Either from source code, or from
 a pre-packaged version. Some of these options will require manually installing
 and/or configuring 3rd party software that NAV depends on, mainly :xref:`PostgreSQL`
-and :xref:`Graphite`.
+and :xref:`Graphite`. Building NAV from source code will also require Node.js
+and npm to be installed.
 
 
 Installing a pre-packaged version of NAV
@@ -96,4 +97,3 @@ For you, we provide two guides:
    </howto/generic-install-from-source>`.
 2. :doc:`A step-by-step, detailed guide on installing NAV from source on a
    Debian GNU/Linux operating system </howto/manual-install-on-debian>`.
-