Nixpacks — MegaLeads SaaS Build Config

🟦 frontend/nixpacks.toml

TOML

frontend/nixpacks.toml

# Auto-detectado: Next.js 14 + Node 20 (.nvmrc)
# Generado por CULTIVA IA · skill nixpacks-build

[phases.setup]
nixPkgs = ["nodejs_20", "openssl"]

[phases.install]
cmds = ["npm ci --include=dev"]

[phases.build]
cmds = [
  "npx prisma generate",
  "npm run build"
]

[start]
cmd = "node server.js"

[variables]
NODE_ENV             = "production"
NEXT_TELEMETRY_DISABLED = "1"
# DATABASE_URL → Railway secret (no en repo)

🐍 backend/nixpacks.toml

TOML

backend/nixpacks.toml

# Auto-detectado: Python 3.12 + FastAPI
# psycopg2 nativo (ARM64) + Pillow + FFmpeg

[phases.setup]
nixPkgs = [
  "python312",
  "postgresql_15",  # psycopg2 compile
  "libffi",
  "ffmpeg",         # procesamiento media
  "libvips"         # Pillow optimizado
]

[phases.install]
cmds = [
  "pip install --upgrade pip",
  "pip install -r requirements.txt"
]

[phases.build]
cmds = [
  "python -m compileall app/"
]

[start]
cmd = "gunicorn app.main:app --worker-class uvicorn.workers.UvicornWorker --bind 0.0.0.0:$PORT --workers 4"

⚡ .github/workflows/deploy.yml — CI/CD Pipeline

YAML

.github/workflows/deploy.yml

name: MegaLeads · Build & Deploy
on:
  push:
    branches: [main]

env:
  REGISTRY: ghcr.io
  IMAGE_FE: ghcr.io/megaleads/frontend
  IMAGE_BE: ghcr.io/megaleads/backend

jobs:
  build-frontend:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Nixpacks
        run: curl -sSL https://nixpacks.com/install.sh | bash

      - name: Build Frontend Image
        run: |
          nixpacks build ./frontend \
            --name $IMAGE_FE:${{ github.sha }} \
            --env NODE_ENV=production \
            --env NEXT_TELEMETRY_DISABLED=1

      - name: Login GHCR & Push
        run: |
          echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
          docker push $IMAGE_FE:${{ github.sha }}
          docker tag  $IMAGE_FE:${{ github.sha }} $IMAGE_FE:latest
          docker push $IMAGE_FE:latest

  build-backend:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Nixpacks
        run: curl -sSL https://nixpacks.com/install.sh | bash

      - name: Build Backend Image
        run: |
          nixpacks build ./backend \
            --name $IMAGE_BE:${{ github.sha }}

      - name: Login GHCR & Push
        run: |
          echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u ${{ github.actor }} --password-stdin
          docker push $IMAGE_BE:${{ github.sha }}
          docker tag  $IMAGE_BE:${{ github.sha }} $IMAGE_BE:latest
          docker push $IMAGE_BE:latest

  deploy-railway:
    needs: [build-frontend, build-backend]
    runs-on: ubuntu-latest
    steps:
      - name: Deploy to Railway
        run: npx @railway/cli up --detach
        env:
          RAILWAY_TOKEN: ${{ secrets.RAILWAY_TOKEN }}

🔍 nixpacks plan ./frontend

CLI OUTPUT

terminal

$ nixpacks plan ./frontend

────────────────────────────────
  Providers    node
  Framework    Next.js
  Node version 20.x (from .nvmrc)
────────────────────────────────

  Phases:

  setup
    nixPkgs: nodejs_20, openssl

  install
    cmds:
      ▸ npm ci --include=dev

  build
    cmds:
      ▸ npx prisma generate
      ▸ npm run build

  start
    cmd: node server.js

────────────────────────────────
  ✓ Plan generated in 0.3s

🏗️ nixpacks build ./backend — Log

BUILD LOG

build log

$ nixpacks build ./backend --name megaleads/backend

[1/5] ▶ Detecting providers...
      ✓ python (requirements.txt)
      ✓ version: 3.12 (.python-version)

[2/5] ▶ Setup phase
      Nix packages:
      + python312
      + postgresql_15      (libpq-dev)
      + ffmpeg
      + libvips
      + libffi

[3/5] ▶ Install phase
      ✓ pip install --upgrade pip     1.2s
      ✓ pip install -r requirements.txt  38.4s
        psycopg2 2.9.9   (native ARM64 ✓)
        Pillow   10.3.0  (libvips ✓)
        fastapi  0.111.0
        + 47 more packages

[4/5] ▶ Build phase
      ✓ python -m compileall app/      0.8s

[5/5] ▶ Finalizing image
      ✓ Image size: 487 MB
      ✓ megaleads/backend:latest

──────────────────────────────
  ✓ Build completed in 3m 41s

📊 Nixpacks vs Dockerfile manual — Comparativa para MegaLeads

Criterio	Dockerfile manual	Nixpacks	Ganador
Tiempo de configuración inicial	2–4h (investigar, probar, depurar)	~10 min (detecta automático)	✓ Nixpacks
psycopg2 nativo ARM64	Requiere 15+ líneas RUN apt-get	nixPkgs = ["postgresql_15"] — 1 línea	✓ Nixpacks
Reproducibilidad	apt puede dar versiones distintas	Nix = hash fijo, siempre idéntico	✓ Nixpacks
Caché de capas	Manual (COPY package.json primero)	Automático por fase	✓ Nixpacks
Multi-stage builds	Control total, pero complejo	Automático (builder / runner)	✓ Nixpacks
Personalización avanzada	Control total	nixpacks.toml cubre 95% casos	≈ Empate
Mantenimiento a largo plazo	Alto (actualizar base image)	Bajo (Railway actualiza builders)	✓ Nixpacks

🔄 Pipeline de build — Fases Nixpacks

1

Detect Auto

Nixpacks escanea package.json / requirements.txt / Cargo.toml y selecciona providers

node (Next.js 14) python 3.12 (FastAPI)

2

Setup Nix store

Instala paquetes del sistema desde Nix store (reproducibles, con hash fijo)

nodejs_20 python312 postgresql_15 ffmpeg libvips openssl

3

Install Cached

Instala dependencias de la app (npm ci / pip install) — capa cacheada si no cambia lockfile

npm ci --include=dev pip install -r requirements.txt

4

Build

Compila assets / genera cliente Prisma / compila Python

npx prisma generate npm run build python -m compileall app/

5

Start

Entrypoint final de la imagen Docker lista para producción

node server.js gunicorn ... --workers 4