Golang在Docker中搭建开发环境示例

# 使用官方 Go 镜像作为基础镜像
FROM golang:1.21-alpine AS builder

# 设置工作目录
WORKDIR /app

# 拷贝 go.mod 和 go.sum（如果有）
COPY go.mod go.sum ./
RUN go mod download

# 拷贝源码
COPY . .

# 构建应用（不静态链接，便于调试）
RUN go build -o main ./cmd/main.go

# 第二阶段：运行时环境（轻量）
FROM alpine:latest
RUN apk --no-cache add ca-certificates

WORKDIR /root/

# 从构建阶段拷贝可执行文件
COPY --from=builder /app/main .

# 暴露端口（根据实际服务调整）
EXPOSE 8080

# 启动命令
CMD ["./main"]

# Dockerfile.dev（用于开发）
FROM golang:1.21-alpine

WORKDIR /app

# 安装 reload 工具（如 air）
RUN apk add --no-cache git curl
RUN curl -sSfL https://raw.githubusercontent.com/cosmtrek/air/master/install.sh | sh -s -- -b /usr/local/bin

# 拷贝依赖
COPY go.mod .
RUN go mod download

# 设置 GOPROXY（国内加速可选）
ENV GOPROXY=https://goproxy.cn,direct

# 暴露服务和 air 热重载端口
EXPOSE 8080
EXPOSE 2345  # air web UI 端口（可选）

# 默认启动 air，实现热重载
CMD ["air", "-c", ".air.toml"]

root = "."
tmp_dir = "tmp"

[build]
cmd = "go build -o ./tmp/main ./cmd/main.go"
delay = 1000
exclude_dir = ["assets", "tmp", "vendor"]
include_ext = ["go", "tpl", "tmpl", "html"]

[proxy]
enabled = false

[log]
time = false

version: '3.8'

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile.dev
    ports:
      - "8080:8080"
      - "2345:2345"  # air web 界面
    volumes:
      - .:/app        # 挂载源码，实现修改实时生效
      - /app/go/pkg   # 避免每次下载依赖
    environment:
      - GO_ENV=development
    working_dir: /app
    command: ["air", "-c", ".air.toml"]

package main

import (
    "fmt"
    "log"
    "net/http"
)

func main() {
    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintf(w, "Hello from Go in Docker! Path: %s\n", r.URL.Path)
    })

    log.Println("Server starting on :8080")
    log.Fatal(http.ListenAndServe(":8080", nil))
}

# 构建并启动服务
docker-compose up --build