💥 feat(agent)!: 添加主机监控代理首版

* 实现周期采集、快照缓存、本地 HTTP API 和主动上报

* 补齐 Linux 和 Windows 主机、网络、资源、进程和 TCP 采集

* 添加服务生命周期管理、配置加载、构建脚本和测试覆盖

BREAKING CHANGE: network.ips 拆分为 network.ipv4s 和 network.ipv6s。

cmd/agent/main.go

@@ -0,0 +1,137 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"mfd-monitor-agent/internal/collector"
+	"mfd-monitor-agent/internal/config"
+	"mfd-monitor-agent/internal/httpapi"
+	"mfd-monitor-agent/internal/reporter"
+	"mfd-monitor-agent/internal/service"
+	"mfd-monitor-agent/internal/snapshot"
+)
+
+const version = "0.1.0"
+
+// main runs the CLI and exits non-zero when a command fails.
+func main() {
+	if err := runCLI(os.Args[1:]); err != nil {
+		_, _ = fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
+
+// runCLI dispatches agent subcommands and loads config before invoking command handlers.
+func runCLI(args []string) error {
+	if len(args) == 0 {
+		args = []string{"run"}
+	}
+	switch args[0] {
+	case "run":
+		fs := flag.NewFlagSet("run", flag.ExitOnError)
+		configPath := fs.String("config", "", "path to JSON config file")
+		if err := fs.Parse(args[1:]); err != nil {
+			return err
+		}
+		cfg, err := config.Load(*configPath)
+		if err != nil {
+			return err
+		}
+		return runAgent(cfg)
+	case "install":
+		cfg, executable, configPath, err := commandConfig(args[1:])
+		if err != nil {
+			return err
+		}
+		return service.NewManager().Install(executable, cfg, service.InstallOptions{ConfigPath: configPath})
+	case "uninstall":
+		cfg, _, _, err := commandConfig(args[1:])
+		if err != nil {
+			return err
+		}
+		return service.NewManager().Uninstall(cfg)
+	case "start":
+		cfg, _, _, err := commandConfig(args[1:])
+		if err != nil {
+			return err
+		}
+		return service.NewManager().Start(cfg)
+	case "stop":
+		cfg, _, _, err := commandConfig(args[1:])
+		if err != nil {
+			return err
+		}
+		return service.NewManager().Stop(cfg)
+	case "version":
+		fmt.Println(version)
+		return nil
+	default:
+		return fmt.Errorf("unknown command %q; expected run, install, uninstall, start, stop, version", args[0])
+	}
+}
+
+// commandConfig parses service command flags and resolves the executable path.
+func commandConfig(args []string) (config.Config, string, string, error) {
+	fs := flag.NewFlagSet("service", flag.ExitOnError)
+	configPath := fs.String("config", "", "path to JSON config file")
+	executableFlag := fs.String("exe", "", "path to agent executable")
+	if err := fs.Parse(args); err != nil {
+		return config.Config{}, "", "", err
+	}
+	cfg, err := config.Load(*configPath)
+	if err != nil {
+		return cfg, "", "", err
+	}
+	executable := *executableFlag
+	if executable == "" {
+		executable, err = os.Executable()
+		if err != nil {
+			return cfg, "", "", err
+		}
+	}
+	return cfg, executable, *configPath, nil
+}
+
+// runAgent starts collection, optional reporting, and the local HTTP API until signaled.
+func runAgent(cfg config.Config) error {
+	logger := slog.New(slog.NewJSONHandler(os.Stdout, nil))
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	startedAt := time.Now().UTC()
+	cache := snapshot.NewCache(collector.New(cfg.HostID), version, startedAt)
+	go cache.Run(ctx, cfg.Collect.Interval.Duration(), cfg.Collect.Timeout.Duration())
+
+	if cfg.Report.Enabled {
+		client := reporter.NewClient(cfg.Report.Endpoint, cfg.Report.Timeout.Duration())
+		go reporter.Run(ctx, cache, client, cfg.Report.Interval.Duration(), logger)
+	}
+
+	server := &http.Server{
+		Addr:              cfg.HTTP.ListenAddress,
+		Handler:           httpapi.New(cache),
+		ReadHeaderTimeout: 5 * time.Second,
+	}
+	go func() {
+		<-ctx.Done()
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		_ = server.Shutdown(shutdownCtx)
+	}()
+
+	logger.Info("agent listening", "address", cfg.HTTP.ListenAddress)
+	err := server.ListenAndServe()
+	if errors.Is(err, http.ErrServerClosed) {
+		return nil
+	}
+	return err
+}