Hatchat 🪓

The aim of Hatchat is to build a slack-like chat application on top of SQLite.

The goal is simplicity for running the server over more features.

Server

To build a binary: go build ./cmd/server.go -o hatchat

If you have just installed, you can do just build

To start the server: ./hatchat

Command line flags:

• addr: the host and port to listen on; defaults to localhost:8080
• db: the location for the chat database. Must be a url like file:chat.db
• log-level: the log level. INFO is default, other options are DEBUG, WARN, ERROR

development

Run modd (to install it: go install github.com/cortesi/modd/cmd/modd) to have the server rebuilt on every change.

environment variables

• LOG_LEVEL - the log level. Default value INFO, valid values DEBUG, INFO, WARN, ERROR

Database Schema Versioning

The database schema is versioned to ensure safe deployments and rollbacks.

How it works

• The schema_version table tracks the current database schema version
• On startup, the server checks if the database version is compatible
• If DB version < server version: Server refuses to start (run migrations first)
• If DB version > server version: Server starts with a warning (safe for rollbacks)

Making schema changes

All schema changes must be backward-compatible to allow server rollbacks:

When modifying schema.sql:

1. Make your backward-compatible change
2. Increment SchemaVersion in server/db/version.go
3. Update the version in the schema.sql INSERT statement
4. Run just models to regenerate database models

CI will fail if you change the schema without bumping the version.