The Big Combo

We've reached the moment of truth. We have an Oracle server (free), Swap memory (to prevent crashing), and a secure Tunnel. Now, let's install the software that will actually work for us.

If we were to install n8n and Evolution API the "old way," we'd have to download files, install Node.js dependencies, configure databases manually... a nightmare.

But since we are using Docker, we'll use the "Combo" strategy with Docker Compose.

1. The Recipe (The Magic File)

Docker Compose allows us to write a "recipe" in a text file. We say: "I want a Postgres database, a Redis cache, the WhatsApp API, and n8n. And I want them all to talk to each other."

Go to your project folder (cd ~/n8n) and edit the file (nano docker-compose.yml). Delete whatever is inside and paste this Full Stack:

YAML

services:
  # 1. Database (Postgres for Evolution)
  postgres:
    image: postgres:15-alpine
    restart: always
    environment:
      POSTGRES_USER: evolution
      POSTGRES_PASSWORD: evolution_password
      POSTGRES_DB: evolution
    volumes:
      - evolution_db:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U evolution"]
      interval: 5s
      timeout: 5s
      retries: 5

  # 2. Cache (Redis for Evolution)
  redis:
    image: redis:alpine
    restart: always
    command: ["redis-server", "--appendonly", "no"]

  # 3. Evolution API v2 (WhatsApp)
  evolution:
    image: atendai/evolution-api:v2.2.2
    restart: always
    ports:
      - "8080:8080"
    environment:
      - SERVER_URL=https://api.YOURDOMAIN.com
      - AUTHENTICATION_API_KEY=[YOUR-AUTHENTICATION-KEY-GOES-HERE]
      - DATABASE_ENABLED=true
      - DATABASE_PROVIDER=postgresql
      - DATABASE_CONNECTION_URI=postgresql://evolution:evolution_password@postgres:5432/evolution
      - CACHE_REDIS_ENABLED=true
      - CACHE_REDIS_URI=redis://redis:6379/0
      - DEL_INSTANCE=false
      # Trick to prevent WhatsApp Web disconnection
      - CONFIG_SESSION_PHONE_VERSION=2.3000.1019430043
    depends_on:
      postgres:
        condition: service_healthy
      redis:
        condition: service_started

  # 4. n8n (Automation)
  n8n:
    image: docker.n8n.io/n8nio/n8n:latest
    restart: always
    ports:
      - "5678:5678"
    environment:
      - N8N_HOST=n8n.YOURDOMAIN.com
      - WEBHOOK_URL=https://n8n.YOURDOMAIN.com/
      - GENERIC_TIMEZONE=America/Sao_Paulo
      - TZ=America/Sao_Paulo
      - N8N_SECURE_COOKIE=false
    volumes:
      - n8n_data:/home/node/.n8n

volumes:
  n8n_data:
  evolution_db:

2. The Integration Secret (Networking)

The magic happens in Docker's internal network. When connecting n8n to the Evolution API, do not use the external address (https://api...). Use the internal Docker network address:

👉 URL: http://evolution:8080

This allows n8n to talk directly to the WhatsApp container via a virtual network cable, without going out to the internet. It is safer, instant, and bypasses the firewall.

3. The Launch Command

After saving the file (Ctrl+O, Ctrl+X), the magic happens with just three words in the terminal:

Bash

docker compose up -d

The server will download the images, create the databases, and connect everything. In about 2 minutes, you will have enterprise-grade infrastructure running on your free machine.

On Thursday, we go for the final test: sending the first message!