NOTICE

This project is being superceded by bert.dashboard

If you are interested in working on the project, even when archived you can still create a fork of it.

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Table of Contents generated with DocToc

• BILL - Bert's Interactive Lesson Loader
• Overview
  • What is this and why did you make it?
  • How did you make this?
  • What's it look like?
• Features
• Quick Start
  • Step 1 - Install
  • Step 2 - Create your configuration file
  • Step 3 - Launch!
    • Usage
• Building the app
• Building the installer
• Developing the app
• Configuration File
  • Configuration File - Defaults
  • Storing credentials - OS Keyring
    • Windows
• Lessons
  • Jinja Templating
• WebTerminal
• Appendix
  • Github Pages

BILL - Bert's Interactive Lesson Loader

Overview

What is this and why did you make it?

Think Katacoda, but instead of a website with learning examples, you have a web app that creates hands-on lessons from markdown-formatted, jina-templated documents, complete with a web terminal for interactive practice.

How did you make this?

• The UI is written in ReactJS
• The API is using Flask

What's it look like?

Here's a screenshot:

Notice the menu dropdown for Available Lessons. The entries are generated dynamically as defined in the app's configuration file.

Features

• Define your lessons catalog in a YAML-formatted configuration file, e.g. lessons.yaml.example
• Lessons are Markdown-formatted files
  1. First rendered as jinja templates
  2. Then rendered as HTML
     
• Web-based terminals via xtermjs component
  See section on WebTerminal
• Local Webterminal websocket is also available
  • Utilizes spyder-terminal component
  • You can practice the lesson material with your own OS/system
    • Simply click on a command, and it will be executed in the underlying shell via web terminal!
    • Default shell is bash (for now)

Quick Start

Step 1 - Install

Note You'll need a minimum python version of 3.7 for the app to work

You can install the app in any of the following ways:

• Install pip package from pypi.org: pip install bertdotbill
• Install pip package from locally cloned repo:
  

git clone https://github.com/berttejeda/bert.bill.git
cd bert.bill
nvm install
npm install -g parcel yarn
yarn install --frozen-lockfile
yarn compile:ui:dev
pip install .

• From the above, nvm is used to install nodejs, and we use yarn for installing package dependencies, and parcel for the web build.
• .nvmrc is set to use node v16.5.0
• To install from the locally cloned repo in development mode, do the same as above, but with pip install -e . instead
• You can install the pip package directly from git repo pip install git+http://www.github.com/berttejeda/bert.bill.git,
  but you'll need to obtain the HTML assets and point the app to them, see the Appendix

Step 2 - Create your configuration file

Using the provided sample config lessons.yaml.example, you can create your own default configuration file, ensuring the following:

• If no config name is explicitly specified:
  • The file name should be lessons.yaml
  • The file should be located in one of the app's search paths,
    see the section on Configuration File
• To specify a config file explicitly from the cli you can use either of --config-file or -f flag, as with bill -f path/to/your/config.yaml
• HTTP(S) web paths are also valid, as with bill -f http://some.website.com/path/to/your/config.yaml

Step 3 - Launch!

• If installed via pip, launch the app from your terminal: bill
• If installed via pip as a development instance, launch via python with python ./bertdotbill/app.py
  

Usage

Usage information can be obtained by invoking the executable with the --help flag, as with: bill --help or python ./bertdotbill/app.py --help.

The help output should be similar to:

usage: bill   [-h] [--username USERNAME] [--password PASSWORD]
              [--lesson-url LESSON_URL]
              [--static-assets-folder STATIC_ASSETS_FOLDER]
              [--config-file CONFIG_FILE] [--cors-origin CORS_ORIGIN]
              [--logfile-path LOGFILE_PATH] [--host-address HOST_ADDRESS]
              [--port PORT]
              [--webterminal-listen-host WEBTERMINAL_LISTEN_HOST]
              [--webterminal-listen-port WEBTERMINAL_LISTEN_PORT]
              [--webterminal-host WEBTERMINAL_HOST]
              [--webterminal-shell WEBTERMINAL_SHELL]
              [--webterminal-shell-command WEBTERMINAL_SHELL_COMMAND]
              [--open-browser-delay OPEN_BROWSER_DELAY]
              [--logfile-write-mode {a,w}] [--config-file-templatized]
              [--api-only] [--webterminal-only] [--all-in-one] [--debug]
              [--no-verify-tls] [--no-render-markdown]

Bert's Interactive Lesson Loader (BILL)

positional arguments:
  run

optional arguments:
  -h, --help            show this help message and exit
  --username USERNAME, -U USERNAME
                        Username, if the URL requires authentication
  --password PASSWORD, -P PASSWORD
                        Password, if the URL requires authentication
  --lesson-url LESSON_URL, -url LESSON_URL
                        The URL for the lesson definition
  --static-assets-folder STATIC_ASSETS_FOLDER, -S STATIC_ASSETS_FOLDER
                        Explicity specify the folder for static HTML assets
  --config-file CONFIG_FILE, -f CONFIG_FILE
                        Path to app configuration file
  --cors-origin CORS_ORIGIN, -o CORS_ORIGIN
                        Override CORS origin pattern
  --logfile-path LOGFILE_PATH, -L LOGFILE_PATH
                        Path to logfile
  --host-address HOST_ADDRESS, -l HOST_ADDRESS
                        Override default host address
  --port PORT, -p PORT  Override default listening port
  --webterminal-listen-host WEBTERMINAL_LISTEN_HOST, -wlh WEBTERMINAL_LISTEN_HOST
                        Override default listening host address for the
                        webterminal socket
  --webterminal-listen-port WEBTERMINAL_LISTEN_PORT, -wlp WEBTERMINAL_LISTEN_PORT
                        Override default listening port for the webterminal
                        socket
  --webterminal-host WEBTERMINAL_HOST, -wh WEBTERMINAL_HOST
                        Override the webterminal socket address to which the
                        UI initially connects
  --webterminal-shell WEBTERMINAL_SHELL, -wS WEBTERMINAL_SHELL
                        Override default shell for the webterminal session
  --webterminal-shell-command WEBTERMINAL_SHELL_COMMAND, -wSc WEBTERMINAL_SHELL_COMMAND
                        Override default shell command for the webterminal
                        session
  --open-browser-delay OPEN_BROWSER_DELAY, -bd OPEN_BROWSER_DELAY
                        Override default time in seconds to delay when opening
                        the system's web browser
  --logfile-write-mode {a,w}, -w {a,w}
                        File mode when writing to log file, 'a' to append, 'w'
                        to overwrite
  --config-file-templatized, -fT
                        Render configuration via jinja2 templating
  --api-only            Don't serve static assets, only start API
  --webterminal-only    Don't serve static assets or start API, only invoke
                        Webterminal Websocket
  --all-in-one, -aio    Run the shell websocket process alongside app
  --debug
  --no-verify-tls, -notls
                        Verify SSL cert when downloading web content
  --no-render-markdown, -nomarkdown

Starting the development instance of the app

• Install Python 3.7+
• Install this project's required version of nodejs (v16.5.0): nvm install
  Note that this command implicitly reads the local .nvmrc
• Install yarn & parcel: npm install -g yarn parcel
• Install node modules: yarn install --frozen-lockfile
• Install python prerequisites: pip3 install -e .
• Launch the development instance of the UI: yarn start:dev:ui
  
• Launch the api and local webterminal process: yarn start:api
  Under the hood, this launches python bertdotbill/app.py --debug --api-only -aio, see package.json

Back to Top

Developing the app

Starting the development instance of the UI will cause it to reload whenever you make changes to any of the UI files under the src folder.

This functionality helps increase UI development velocity.

I have not yet implemented similar functionality for the API files under bertdotbill, so you'll have to kill and reload the API whenever you make changes.

Configuration File

The configuration file is read by the Flask API process, and is a YAML-formatted file.

As mentioned above, a sample configuration file is provided: lessons.yaml.example

If no configuration is specified via the cli, the web app will attempt to find the config file in the following locations:

• Under ~/lessons.yaml
• Adjacent to the app, i.e. ./lessons.yaml
• Under ~/.bill/lessons.yaml
• Under /etc/lessons.yaml

Do review the comments in the sample file, as these explain how the sections are interpreted/handled by the UI.

Configuration File - Defaults

If no settings can be found, the app will resort to its defaults, see defaults.py

As such, the defaults settings call for the import of an external config, hosted in my bert.lessons repo:
see bert.lessons/lessons.yaml

This external config is where I am listing all of my (mostly) hand-crafted tutorials and learning materials.

Lessons

As already mentioned, lessons are Markdown-formatted files interpreted as jinja templates.

You can define a lesson catalog in the configuration file.

If these files are stored in a password-protected web location, you'll need to specify credentials via the cli with --username and --password
or via environmental variables GLOBAL_USERNAME and GLOBAL_PASSWORD

TODO

Implement per-lesson credentials

Jinja Templating

To add to the templating goodies provided by the Jinja library, I've exposed the OS Environment via the environment key of a special variable named session.

This means you should be able to dynamically load any OS-level environment variable into your lesson material, e.g.

# Overview

{% set USERNAME = session['environment'].get('USER') or session['environment'].get('USERNAME')  %}
Hello {{ USERNAME }}, welcome to Lesson 1

WebTerminal

Every lesson rendered through the app includes a web-based terminal emulator component that allows for practicing the lesson material.

These web terminals are embedded in the user interface, available at its footer.

As mentioned before, the underlying technology for these web terminals is xterm.js.

As such, the xterm.js component requires a websocket to a bash process.

By default, the bert.bill web app will attempt to connect to a local instance of the websocket via http://127.0.0.1:10000/.

You can get this websocket running either by:

• Installing bertdotbill with pip install bertdotbill and running bill -aio or by installing all requirements and running python bertdotbill/app.py -aio
  Doing so will launch a local websocket that forwards keystrokes to a bash process on your system
• Running the pre-built docker image: docker run -it --name webterminal --rm -p 10001:10001 berttejeda/bill-webterminal

Either of the commands above will start the websocket and bash process on localhost:10001.

Feel free to adjust either approach to your need.

Read more bert.bill.webterminal github project

Appendix

Github Pages

If you want to publish the assets from your own fork of this repo:

1. Fork this repo
2. Configure Github Pages
3. Run yarn install to initialize the project requirements
4. Run yarn deploy to publish the static assets to the gh-pages branch