Docker Setup

Kazier’s backend is a single Go binary (Tesseract embedded for OCR) and its database is PostgreSQL 17. The repository ships a docker-compose.yml that runs the whole stack: the database and the backend API.

Services

Service	Image	Purpose
`postgres`	`postgres:17-alpine`	Metadata database
`backend`	built from `./backend` (`Dockerfile`)	Go API (image also published to Docker Hub)

The published image is docker.io/thirdshop/kasier (tagged vX.Y.Z + latest).

The paddleocr service seen in the historical file was rejected in favor of Tesseract, which the backend calls directly as a system command.

Prerequisites

Docker with Compose V2
mandatory environment variables (see Environment Variables): AUTH_SECRET, ADMIN_USERNAME, ADMIN_PASSWORD

docker-compose.yml

services:
  postgres:
    image: postgres:17-alpine
    ports:
      - "5432:5432"
    environment:
      POSTGRES_DB: ${POSTGRES_DB:-kazier_dev}
      POSTGRES_USER: ${POSTGRES_USER:-kazier}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-kazier}
    volumes:
      - postgres-data:/var/lib/postgresql/data
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER:-kazier}"]
      interval: 10s
      timeout: 5s
      retries: 5

  backend:
    build:
      context: ./backend
      dockerfile: Dockerfile
      args:
        VERSION: ${VERSION:-dev}
    ports:
      - "${PORT:-8080}:8080"
    environment:
      PORT: 8080
      DATABASE_URL: postgres://${POSTGRES_USER:-kazier}:${POSTGRES_PASSWORD:-kazier}@postgres:5432/${POSTGRES_DB:-kazier_dev}?sslmode=disable
      UPLOAD_DIR: /app/uploads
      MAX_FILE_SIZE_MB: ${MAX_FILE_SIZE_MB:-50}
      OCR_LANG: ${OCR_LANG:-fra+eng}
      AUTH_SECRET: ${AUTH_SECRET:?AUTH_SECRET required}
      ADMIN_USERNAME: ${ADMIN_USERNAME:?ADMIN_USERNAME required}
      ADMIN_PASSWORD: ${ADMIN_PASSWORD:?ADMIN_PASSWORD required}
    volumes:
      - backend-uploads:/app/uploads
    depends_on:
      postgres:
        condition: service_healthy
    restart: unless-stopped

volumes:
  postgres-data:
  backend-uploads:

Commands

# Copy the example env and edit the secrets
cp backend/.env.example .env

# Start the whole stack (waits for the database healthcheck)
docker compose up -d --build

# Health check
curl http://localhost:8080/api/v1/health
# → {"data":{"status":"healthy"}}

# Follow logs
docker compose logs -f

# Stop the stack
docker compose down

# Stop and delete the data volume (⚠️ destroys metadata)
docker compose down -v

Rotate POSTGRES_PASSWORD, AUTH_SECRET and the admin credentials outside of the compose file (e.g. your .env, Docker secrets). Never use the defaults in production.

Container environment

Variable	Default	Description
`POSTGRES_DB`	`kazier_dev`	Database created at first boot
`POSTGRES_USER`	`kazier`	Database user
`POSTGRES_PASSWORD`	`kazier`	Password (change for production)
`VERSION`	`dev`	Build arg injected into `main.version` (ldflags)

Backend variables are documented in Environment Variables.

Backend image

The backend image is built by a multi-stage Dockerfile:

Builder (golang:1.26-alpine): compiles a static binary with CGO_ENABLED=0 and the version baked in (ldflags).
Runtime (alpine, non-root user): ships Tesseract with English and French language data (fra+eng, default OCR_LANG), ca-certificates, a persistent UPLOAD_DIR at /app/uploads, a Docker HEALTHCHECK, and OCI labels (AGPL-3.0-only, source URL, version).

The server listens on all interfaces (:PORT, default 8080) — no HOST variable is needed.

To run the published image instead of building it locally:

docker run --rm \
  -e AUTH_SECRET="$AUTH_SECRET" \
  -e ADMIN_USERNAME="$ADMIN_USERNAME" \
  -e ADMIN_PASSWORD="$ADMIN_PASSWORD" \
  -e DATABASE_URL="postgres://kazier:kazier@host.docker.internal:5432/kazier_dev?sslmode=disable" \
  -p 8080:8080 \
  thirdshop/kasier:latest

Docker Setup

Docker Setup

Services

Prerequisites

docker-compose.yml

Commands

Container environment

Backend image

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