Docker Compose编排多服务项目：网络卷健康检查与启动顺序实践

Docker Engine: 24.0.6
Docker Compose: v2.23.0（docker compose 子命令，非docker-compose v1）
镜像版本：
  nginx:1.25.3-alpine
  golang:1.21.3-alpine（构建阶段）
  postgres:15.4-alpine
  redis:7.2.3-alpine

                    ┌─────────────┐
                    │   nginx     │
                    │  :8080→:80  │
                    └──────┬──────┘
                           │ 反向代理
                    ┌──────▼──────┐
                    │   golang    │
                    │  API :8081  │
                    └──────┬──────┘
                    ┌──────▼──────┐    ┌─────────────┐
                    │ postgresql  │◄───►    redis    │
                    │  :5432      │    │  :6379      │
                    └─────────────┘    └─────────────┘

version: "3.8"

# 自定义网络：bridge驱动，实现服务发现
networks:
  app_network:
    driver: bridge
    ipam:
      config:
        - subnet: 172.28.0.0/16
          gateway: 172.28.0.1

# 命名卷：数据持久化
volumes:
  postgres_data:
    name: myapp_pgdata
  redis_data:
    name: myapp_redisdata

services:
  # 1. PostgreSQL：用pg_isready做健康检查
  postgres:
    image: postgres:15.4-alpine
    container_name: myapp_pg
    restart: unless-stopped
    environment:
      POSTGRES_USER: appuser
      POSTGRES_PASSWORD: ${PG_PASSWORD:-apppass123}
      POSTGRES_DB: myapp
      PGDATA: /var/lib/postgresql/data/pgdata
    volumes:
      - postgres_data:/var/lib/postgresql/data
      - ./init.sql:/docker-entrypoint-initdb.d/init.sql:ro
    networks:
      app_network:
        ipv4_address: 172.28.0.10
    ports:
      - "5432:5432"
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U appuser -d myapp"]
      interval: 5s
      timeout: 3s
      retries: 5
      start_period: 10s   # 给首次初始化留时间

  # 2. Redis：用redis-cli ping
  redis:
    image: redis:7.2.3-alpine
    container_name: myapp_redis
    restart: unless-stopped
    command: redis-server --appendonly yes --maxmemory 256mb --maxmemory-policy allkeys-lru
    volumes:
      - redis_data:/data
    networks:
      app_network:
        ipv4_address: 172.28.0.11
    ports:
      - "6379:6379"
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 3s
      retries: 3

  # 3. Golang API：编译后运行，健康检查走HTTP
  golang-api:
    build:
      context: ./api
      dockerfile: Dockerfile
    image: myapp-api:1.0.0
    container_name: myapp_api
    restart: unless-stopped
    environment:
      DB_HOST: postgres
      DB_PORT: 5432
      DB_USER: appuser
      DB_PASSWORD: ${PG_PASSWORD:-apppass123}
      DB_NAME: myapp
      REDIS_ADDR: redis:6379
      GIN_MODE: release
    depends_on:
      postgres:
        condition: service_healthy   # 关键：等待健康检查通过
      redis:
        condition: service_healthy
    networks:
      app_network:
        ipv4_address: 172.28.0.12
    ports:
      - "8081:8081"
    healthcheck:
      test: ["CMD", "wget", "-qO-", "http://localhost:8081/healthz"]
      interval: 10s
      timeout: 5s
      retries: 3
      start_period: 15s

  # 4. Nginx：最后启动，等待API就绪
  nginx:
    image: nginx:1.25.3-alpine
    container_name: myapp_nginx
    restart: unless-stopped
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
      - ./static:/usr/share/nginx/html:ro
    ports:
      - "8080:80"
    depends_on:
      golang-api:
        condition: service_healthy
    networks:
      app_network:
        ipv4_address: 172.28.0.13
    healthcheck:
      test: ["CMD", "wget", "-qO-", "http://localhost/healthz"]
      interval: 10s
      timeout: 3s
      retries: 3

# 构建阶段
FROM golang:1.21.3-alpine AS builder
WORKDIR /app
COPY go.mod go.sum ./
RUN go mod download
COPY . .
RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /app/main .

# 运行阶段
FROM alpine:3.19
WORKDIR /app
RUN apk --no-cache add ca-certificates wget
COPY --from=builder /app/main .
EXPOSE 8081
CMD ["./main"]