55 lines
1.4 KiB
Go
55 lines
1.4 KiB
Go
// 一个最小的 Go HTTP 服务，用来演示多阶段构建、健康检查和优雅退出。
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package main
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import (
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"context"
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"errors"
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"log"
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"net/http"
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"os"
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"os/signal"
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"syscall"
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"time"
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)
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func newMux() *http.ServeMux {
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mux := http.NewServeMux()
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mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, r *http.Request) {
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w.Write([]byte("ok"))
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})
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mux.HandleFunc("GET /api/hello", func(w http.ResponseWriter, r *http.Request) {
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w.Header().Set("Content-Type", "application/json")
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w.Write([]byte(`{"message":"hello from container"}`))
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})
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return mux
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}
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func main() {
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addr := ":" + getenv("PORT", "8080")
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srv := &http.Server{Addr: addr, Handler: newMux(), ReadHeaderTimeout: 5 * time.Second}
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// 容器停止时 Docker 先发 SIGTERM，等待一段时间（默认 10 秒）后才 SIGKILL
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ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
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defer stop()
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go func() {
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log.Printf("listening on %s", addr)
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if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
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log.Fatal(err)
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}
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}()
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<-ctx.Done()
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shutdownCtx, cancel := context.WithTimeout(context.Background(), 8*time.Second)
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defer cancel()
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if err := srv.Shutdown(shutdownCtx); err != nil { // 不再接新请求，等正在处理的请求完成
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log.Printf("shutdown: %v", err)
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}
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log.Println("bye")
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}
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func getenv(k, def string) string {
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if v := os.Getenv(k); v != "" {
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return v
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}
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return def
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}
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