Trading Bot Docker Container Setup

Docker Container Setup for Trading Bot

Trading bot run directly on VPS without isolation — dependencies problems, unpredictable restarts on crash and lack of reproducibility. Docker solves all this in couple hours of setup. Main tasks: environment isolation, automatic restart on failure, secure API key passing, logging, updates without downtime.

Dockerfile for Python Bot

FROM python:3.12-slim

# System dependencies (if need C-extensions like ta-lib)
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app

# First dependencies (layer cache when only code changes)
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

COPY . .

# Don't run as root
RUN adduser --disabled-password --gecos '' botuser
USER botuser

CMD ["python", "-u", "bot.py"]

Flag -u in Python disables stdout buffering — logs visible immediately, not after flush.

docker-compose with Secrets and Auto-restart

services:
  trading-bot:
    build: .
    container_name: trading_bot
    restart: unless-stopped  # restart on failure, but not on manual stop

    environment:
      - PYTHONUNBUFFERED=1
      - TZ=UTC

    # Secrets via env_file, don't hardcode in compose
    env_file:
      - .env.secrets

    volumes:
      - ./data:/app/data          # bot persistent data
      - ./logs:/app/logs          # logs outside container

    # Resource limits
    deploy:
      resources:
        limits:
          memory: 512M
          cpus: '0.5'

    # Health check — Docker restart if bot hangs
    healthcheck:
      test: ["CMD", "python", "-c", "import os; os.path.exists('/app/data/heartbeat')"]
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 10s

    logging:
      driver: "json-file"
      options:
        max-size: "50m"
        max-file: "5"

.env.secrets (never commit to git):

BINANCE_API_KEY=your_key_here
BINANCE_SECRET=your_secret_here
TELEGRAM_BOT_TOKEN=notification_token

Add .env.secrets to .gitignore. Better approach — Docker Secrets or HashiCorp Vault, but for simple bot env_file enough if repo is private.

Health Check via Heartbeat File

Bot writes timestamp to file every N seconds. Docker checks file freshness:

# In bot — heartbeat every 10 sec
import threading
import time
import pathlib

def heartbeat_loop():
    while True:
        pathlib.Path('/app/data/heartbeat').touch()
        time.sleep(10)

threading.Thread(target=heartbeat_loop, daemon=True).start()

# healthcheck command checks file modified < 60 sec ago
test: ["CMD", "bash", "-c", "[ $(($(date +%s) - $(date +%s -r /app/data/heartbeat))) -lt 60 ]"]

Update Without Full Downtime

# Rebuild and replace container
docker-compose build trading-bot
docker-compose up -d --no-deps trading-bot

--no-deps doesn't touch other services. Container stops, new one starts — downtime 5-10 seconds. For trading bot usually acceptable.

Useful Commands

# Run
docker-compose up -d

# Real-time logs
docker-compose logs -f trading-bot

# Status
docker-compose ps

# Debug inside container
docker-compose exec trading-bot bash

# Restart
docker-compose restart trading-bot