阶段2（下）：运维专题 Docker/Nginx/Linux/CI-CD/Git 的课程、企业场景、面试题和可运行示例

topics/devops/docker/examples/go-api-compose/main.go

@@ -0,0 +1,54 @@
+// 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。
+package main
+
+import (
+	"context"
+	"errors"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+)
+
+func newMux() *http.ServeMux {
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte("ok"))
+	})
+	mux.HandleFunc("GET /api/hello", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{"message":"hello from container"}`))
+	})
+	return mux
+}
+
+func main() {
+	addr := ":" + getenv("PORT", "8080")
+	srv := &http.Server{Addr: addr, Handler: newMux(), ReadHeaderTimeout: 5 * time.Second}
+
+	// 容器停止时 Docker 先发 SIGTERM，等待一段时间（默认 10 秒）后才 SIGKILL
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+	go func() {
+		log.Printf("listening on %s", addr)
+		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+			log.Fatal(err)
+		}
+	}()
+	<-ctx.Done()
+	shutdownCtx, cancel := context.WithTimeout(context.Background(), 8*time.Second)
+	defer cancel()
+	if err := srv.Shutdown(shutdownCtx); err != nil { // 不再接新请求，等正在处理的请求完成
+		log.Printf("shutdown: %v", err)
+	}
+	log.Println("bye")
+}
+
+func getenv(k, def string) string {
+	if v := os.Getenv(k); v != "" {
+		return v
+	}
+	return def
+}