Welcome FaceBook Chat Bot

Development Technologies

At the moment of developing this project, I used the following versions of Elixir and Erlang.

iex> mix hex.info

Hex:    1.0.1
Elixir: 1.13.0
OTP:    24.0.4

Built with: Elixir 1.13.0 and OTP 22.3

Export System variables

The following variables are required to be exported

FACEBOOK_PAGE_ACCESS_TOKEN = <page_access_token>
FACEBOOK_WEBHOOK_VERIFY_TOKEN = <random_string used while adding webhook>

Running Application

mix release digi_coin

mix deps.get
mix release digi_coin

I added the releases path to ./releases

So, we are provided with following commands.

Release created at releases!

    # To start your system
    releases/bin/digi_coin start

Once the release is running:

    # To connect to it remotely
    releases/bin/digi_coin remote

    # To stop it gracefully (you may also send SIGINT/SIGTERM)
    releases/bin/digi_coin stop

To list all commands:

    releases/bin/digi_coin

iex -S mix

Running Interactively

Receiving Updates as Webhooks

Expose a local web server to the internet

The ngrok will allow local webserver running to internet. So, we can use our local webserver url as webhook url at blocknative.

run the following command

ngrok http 4000

You will see the following output.

Session Status                online
Version                       2.3.40
Region                        United States (us)
Web Interface                 http://127.0.0.1:4040
Forwarding                    http://14fc-136-185-52-176.ngrok.io -> http://localhost:4000
Forwarding                    https://14fc-136-185-52-176.ngrok.io -> http://localhost:4000
Connections                   ttl     opn     rt1     rt5     p50     p90

The urls may look different as ngrok assigns random hexadecimal names to the HTTP tunnels it opens.
Here the url is http://14fc-136-185-52-176.ngrok.io which will act our webhook base.

Make sure you add http://14fc-136-185-52-176.ngrok.io/blocknative/webhook as webhook url for facebook.

Project Challenges

• Framing of Templates and Organizing the modules
• Message Handler for identifying type of web hook events
• Using docker to releases with Elixir.