Matrix Based Selfhosted Chatbot

Introduction

I deployed a selfhosted chatbot in order to assist me on handling local workflows, while I am remote from home (eg.: office, coffeshop, library). I found that matrix chat app and implementing a bot on top of it is currently the most private, secure and robust solution. Because Matrix is prefered communications application for government-grade institutions, such that France government decided to selfhost their own Matrix instances and replace usage of WhatsApp or Telegram for official purposes. There are many services I selfhost and occasionally I need to reach them remotely. Some of those are job scheduler, bookmark/video archiver, backup system, etc. In this post I document my process of deploying * a Matrix server and * its bot on my home server.

(1) write compose file

version: '3.3'

services:
  app:
    image: matrixdotorg/synapse
    restart: unless-stopped
    ports:
      - [external-port]:[internal-port]
    volumes:
      - /path/on/host/machine/for/matrix/data:/data

(2) generate new config file

docker run -it --rm -v /path/on/host/machine/for/matrix/data:/data \
	-e SYNAPSE_SERVER_NAME=matrix.DOMAIN_NAME.com \
	-e SYNAPSE_REPORT_STATS=yes \
	matrixdotorg/synapse:latest generate

Running this command genenrates homeserver.yml file for my instance.
Update DOMAIN_NAME with my own address with sub-domain.

Finally you should see generated config files in your data dir:

(3) expose service to remote

create new site via nginx

sudo nano /etc/nginx/sites-available/matrix.conf

write reverse proxy configurations

server {
  server_name SUB_DOMAIN_NAME.DOMAIN_NAME.com;
  location / {
    proxy_pass http://localhost:[external-port];
    }
}

sudo ln -s /etc/nginx/sites-available/matrix.conf /etc/nginx/sites-enabled/matrix.conf

(4) create certificate with certbot

call certbot of Let’s Encrypt to generate a new certificate

sudo certbot --nginx -d SUB_DOMAIN_NAME.DOMAIN_NAME.com

(5) connect to your instance via client

Once your matrix synapse server is up and running, you should connect to it via a client
Element seems appropriate as a decentralized client.
Navigate to Element on your Browser and click: Sign In -> Homeserver -> Edit

(6) skip federation configuration

Federation enables one’s selfhosted instance to connect other server instances and chat with users signed on those instances.
Since my own chatbot assistant does not require interaction with users on other instances, here I am not implementing federation.

(7) create user

Create a user to sign in through client.
User registration on the home server instance should be enabled. Add the line below into homeserver.yaml config file:

enable_registration: true

Enabling registering without verification is not secure. Matrix will warn about it and recommends implementing mail verification.

enable_registration_without_verification: false

You can register to your selfhosted instance using Element client:
- https://app.element.io/#/register

(8) simple chatbot service

There exists templates to build chatbot on Matrix. I prefered using eno-bot to build on top of it.

write compose file:

version: '3'

services:
  matrix-eno-bot:
    container_name: matrix-eno-bot
    image: 'matrix-eno-bot:latest'
    build: ./host/path/to/repo/dir
    restart: unless-stopped
    volumes:
      - ./path/to/persistent/host/dir:/bot

Default usage is clearly explained on the README.md of maintainers repository:

chatbot assistant matrix seflhosted