udv-bot

Q&A bot for internal use at UDV

Project structure

Crates

• bot - telegram bot
• cli - CLI tool for quick database backups
• server - web server for managing bot data
• db - collections of common database related functions

Directories

• static - directory for static documents, that bot can answer with

Development

Bot

Install sqlite3 build dependencies and sqlite3 CLI

# For Debian
$ sudo apt-get install libsqlite3-dev sqlite

Get yourself a token from @Botfather. It looks something like 123456789:qweqweqwe

Set the environmental variables in .env file

TELOXIDE_TOKEN=<Your token here>
DB_PATH=<Absolute path to your database>
DATABASE_URL="sqlite:<Absolute path to your database>"
STATIC_DIR=./static
USE_AUTH=false

Install sqlx-cli and run database migrations

$ cargo install sqlx-cli
$ cd db
$ sqlx database setup

Add some data to the database

$ sqlite3 <db file path>
sqlite> insert into categories(name) values("test1");
sqlite> insert into categories(name) values("test2");
sqlite> insert into questions(question, answer, category) values("funny question1", "funny an
swer1", 1);
sqlite> insert into questions(question, answer, category, attachment) values("funny question2", "funny an
swer2", 2, "qwe.png");

To start the bot run

cargo run -p bot

CMS

To start server run

cargo run -p server

Log level can be adjusted with environmental variable RUST_LOG

RUST_LOG=tower_http=trace cargo run -p server

Technology

Web

• Server: axum
• Templates: askama
• Client-side rendering: htmx
• CSS: Uikit

Bot

• Framework: teloxide

Database

• Migrations and queries: sqlx

API Design "gotchas"

• Since frontend is using HTMX, a lot of endpoints just render specific parts of html. For example, every row in a table is its own template. This allows to append rows to a table without the need to rerender the whole page.
• Since frontend is using HTMX, some hacks are used to deal with html forms (for example, checkbox behaviour)
• In order to get the file server working, kinda weird strategy is employed. First, ServeDir service is nested to /static path. The endpoint, that is getting called from the client, sends back a redirect in order to trigger browser native file download interaction.
• Reordering is not interactive, i.e. user sorts the table in the desired way, then saves the changes. Avoids a lot of headache and redrawing.