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

2026-10-23 15:36:06 +08:00
1 parent 5eb67c5d08
commit b8010a74f3
@@ -0,0 +1,4 @@
+.git
+*.md
+*_test.go
+compose.yaml
@@ -0,0 +1,19 @@
+# syntax=docker/dockerfile:1
+# ---------- 构建阶段：带完整 Go 工具链 ----------
+FROM golang:1.26-alpine AS build
+WORKDIR /src
+# 先只复制依赖描述文件，依赖不变时这一层可以复用缓存
+COPY go.mod ./
+RUN go mod download
+COPY . .
+# 静态编译，去掉调试信息减小体积
+RUN CGO_ENABLED=0 go build -trimpath -ldflags="-s -w" -o /out/api .
+
+# ---------- 运行阶段：只放二进制 ----------
+FROM gcr.io/distroless/static-debian12:nonroot
+COPY --from=build /out/api /api
+ENV PORT=8080
+EXPOSE 8080
+USER nonroot:nonroot
+# exec 形式，进程是 PID 1，能直接收到 SIGTERM
+ENTRYPOINT ["/api"]
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+# 本地开发环境：docker compose up -d --build
+# 镜像版本仅作示例，按项目需要调整
+services:
+  api:
+    build: .
+    ports:
+      - "8080:8080"
+    environment:
+      DATABASE_URL: postgres://app:app@db:5432/app?sslmode=disable   # 服务名 db 就是主机名
+      REDIS_URL: redis://redis:6379/0
+    depends_on:
+      db:
+        condition: service_healthy   # 等数据库健康检查通过再启动
+      redis:
+        condition: service_started
+    restart: unless-stopped
+
+  db:
+    image: postgres:17
+    environment:
+      POSTGRES_USER: app
+      POSTGRES_PASSWORD: app        # 仅限本地开发；生产用密钥管理
+      POSTGRES_DB: app
+    volumes:
+      - pgdata:/var/lib/postgresql/data   # 命名卷：容器删除后数据仍在
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U app -d app"]
+      interval: 5s
+      timeout: 3s
+      retries: 10
+
+  redis:
+    image: redis:7-alpine
+
+volumes:
+  pgdata:
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+module example/goapi
+
+go 1.22
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+// 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
+}
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+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestRoutes(t *testing.T) {
+	srv := httptest.NewServer(newMux())
+	defer srv.Close()
+	for path, want := range map[string]int{"/healthz": 200, "/api/hello": 200, "/nope": 404} {
+		resp, err := http.Get(srv.URL + path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		resp.Body.Close()
+		if resp.StatusCode != want {
+			t.Errorf("%s = %d, want %d", path, resp.StatusCode, want)
+		}
+	}
+}