Self-Hosting

Run your own instance of Crit Web

Prerequisites

Docker (with Compose)
PostgreSQL 17 (or use the bundled one in docker-compose)

Quick start with Docker Compose

Download the example files and configure your environment:

curl -o docker-compose.yml https://raw.githubusercontent.com/tomasz-tomczyk/crit-web/main/contrib/docker-compose.example.yml
curl -o .env https://raw.githubusercontent.com/tomasz-tomczyk/crit-web/main/.env.example

Generate a secret key and set it in .env:

openssl rand -base64 64

Update SECRET_KEY_BASE and PHX_HOST in .env, then start the services:

docker compose up -d

Environment Variables

Variable	Required	Description
`DATABASE_URL`	Yes	PostgreSQL connection URL
`SECRET_KEY_BASE`	Yes	64+ byte secret for signing cookies
`PHX_HOST`	Yes	Hostname where crit-web is served
`PHX_SERVER`	Yes	Set to `true` to start the web server
`PORT`	No	HTTP port (default: 4000)

Running with your own Postgres

If you already have a PostgreSQL instance, skip the db service and run the app container directly:

docker run -d \
  --name crit-web \
  --restart unless-stopped \
  -e DATABASE_URL="postgres://user:pass@your-host:5432/crit" \
  -e SECRET_KEY_BASE="your-generated-secret" \
  -e PHX_HOST="crit.example.com" \
  -e PHX_SERVER=true \
  -e PORT=4000 \
  -p 4000:4000 \
  ghcr.io/tomasz-tomczyk/crit-web:latest \
  sh -c "/app/bin/migrate && /app/bin/server"

Updating

Pull the latest image and restart:

docker compose pull
docker compose up -d

Docker image

Images are published to GitHub Container Registry. Available tags:

latest — latest stable release
main — bleeding edge (built from main branch)
1.2.3 — specific version