Add guest root cause diagnostics

README.md

@@ -342,6 +342,22 @@ APT-обновления и необходимость перезагрузки.
 health-check, число перезапусков, CPU и память. Агент сам подключается к Dashboard
 каждые 10 секунд; открывать входящий порт внутри гостевой системы не нужно.
 
+В подробностях агента systemd-службы разделяются на системные, установленные
+дополнительно и локальные unit-файлы. Для каждой службы показываются пакет и путь
+unit-файла, время запуска, число перезапусков, последний exit code, память и
+накопленное CPU-время, когда соответствующий accounting доступен в systemd.
+
+Расширенная диагностика агента включает последние сообщения проблемных служб,
+`Requires`/`After`, PID, команду запуска и слушающие порты; выявляет частые
+рестарты, OOM-kill и процессы в D-state. Отдельно отображаются top процессов по
+CPU и RAM с накопленным I/O, swap, PSI pressure, все постоянные файловые системы,
+их заполнение и использование inode.
+
+Панель «Диагностика homelab» и карта сопоставляют известные IP и порты с VM/LXC,
+агентом, systemd-службой или Docker-контейнером и настроенной HTTP/TCP-проверкой.
+Связи по PID и порту считаются подтверждёнными; совпадения только по названию
+помечаются как предположение.
+
 Откройте `Настройки → Агенты`, укажите адрес Dashboard, доступный из VM/LXC, и
 VMID. Кнопка создаст готовую команду установки. Одноразовый токен действует 15
 минут и после регистрации заменяется индивидуальным секретом агента.

agent.go

@@ -58,36 +58,65 @@ type AgentInterface struct {
 }
 
 type AgentService struct {
-	Name        string `json:"name"`
-	State       string `json:"state"`
-	SubState    string `json:"subState"`
-	Description string `json:"description"`
+	Name        string     `json:"name"`
+	State       string     `json:"state"`
+	SubState    string     `json:"subState"`
+	Description string     `json:"description"`
+	Origin      string     `json:"origin"`
+	UnitPath    string     `json:"unitPath,omitempty"`
+	Package     string     `json:"package,omitempty"`
+	Restarts    uint64     `json:"restarts"`
+	ExitCode    int        `json:"exitCode"`
+	StartedAt   int64      `json:"startedAt,omitempty"`
+	MemoryBytes uint64     `json:"memoryBytes,omitempty"`
+	CPUSeconds  float64    `json:"cpuSeconds,omitempty"`
+	MainPID     int        `json:"mainPid,omitempty"`
+	ExecStart   string     `json:"execStart,omitempty"`
+	Requires    []string   `json:"requires,omitempty"`
+	After       []string   `json:"after,omitempty"`
+	ListenPorts []int      `json:"listenPorts,omitempty"`
+	Logs        []AgentLog `json:"logs,omitempty"`
+	Flapping    bool       `json:"flapping"`
+}
+
+type AgentIssue struct {
+	Time    int64  `json:"time"`
+	Unit    string `json:"unit"`
+	Message string `json:"message"`
 }
 
 type AgentReport struct {
-	Hostname         string           `json:"hostname"`
-	MachineID        string           `json:"machineId"`
-	Version          string           `json:"version"`
-	OS               string           `json:"os"`
-	Arch             string           `json:"arch"`
-	OSName           string           `json:"osName"`
-	Kernel           string           `json:"kernel"`
-	UptimeSeconds    int64            `json:"uptimeSeconds"`
-	Load1            float64          `json:"load1"`
-	CPUPercent       float64          `json:"cpuPercent"`
-	MemoryTotal      uint64           `json:"memoryTotal"`
-	MemoryUsed       uint64           `json:"memoryUsed"`
-	RootTotal        uint64           `json:"rootTotal"`
-	RootUsed         uint64           `json:"rootUsed"`
-	DockerAvailable  bool             `json:"dockerAvailable"`
-	DockerError      string           `json:"dockerError,omitempty"`
-	Containers       []AgentContainer `json:"containers"`
-	Interfaces       []AgentInterface `json:"interfaces"`
-	Services         []AgentService   `json:"services"`
-	UpdatesAvailable int              `json:"updatesAvailable"`
-	RebootRequired   bool             `json:"rebootRequired"`
-	InventoryAt      int64            `json:"inventoryAt"`
-	CollectedAt      int64            `json:"collectedAt"`
+	Hostname         string            `json:"hostname"`
+	MachineID        string            `json:"machineId"`
+	Version          string            `json:"version"`
+	OS               string            `json:"os"`
+	Arch             string            `json:"arch"`
+	OSName           string            `json:"osName"`
+	Kernel           string            `json:"kernel"`
+	UptimeSeconds    int64             `json:"uptimeSeconds"`
+	Load1            float64           `json:"load1"`
+	CPUPercent       float64           `json:"cpuPercent"`
+	MemoryTotal      uint64            `json:"memoryTotal"`
+	MemoryUsed       uint64            `json:"memoryUsed"`
+	SwapTotal        uint64            `json:"swapTotal"`
+	SwapUsed         uint64            `json:"swapUsed"`
+	RootTotal        uint64            `json:"rootTotal"`
+	RootUsed         uint64            `json:"rootUsed"`
+	DockerAvailable  bool              `json:"dockerAvailable"`
+	DockerError      string            `json:"dockerError,omitempty"`
+	Containers       []AgentContainer  `json:"containers"`
+	Interfaces       []AgentInterface  `json:"interfaces"`
+	Services         []AgentService    `json:"services"`
+	Issues           []AgentIssue      `json:"issues"`
+	Processes        []AgentProcess    `json:"processes"`
+	Filesystems      []AgentFilesystem `json:"filesystems"`
+	ListenPorts      []AgentListenPort `json:"listenPorts"`
+	Pressure         AgentPressure     `json:"pressure"`
+	OOMKills         []AgentLog        `json:"oomKills"`
+	UpdatesAvailable int               `json:"updatesAvailable"`
+	RebootRequired   bool              `json:"rebootRequired"`
+	InventoryAt      int64             `json:"inventoryAt"`
+	CollectedAt      int64             `json:"collectedAt"`
 }
 
 type agentInventory struct {
@@ -115,6 +144,12 @@ var guestInventory struct {
 	value agentInventory
 }
 
+var guestIssues struct {
+	sync.Mutex
+	value       []AgentIssue
+	collectedAt time.Time
+}
+
 var agentBinaryInfo struct {
 	sync.Once
 	manifest AgentUpdateManifest
@@ -480,6 +515,11 @@ func collectAgentReport() AgentReport {
 	}
 	report.CPUPercent = sampleAgentCPU()
 	report.Interfaces = collectAgentInterfaces()
+	report.Processes = collectAgentProcesses()
+	report.Filesystems = collectAgentFilesystems()
+	report.ListenPorts = collectAgentListenPorts()
+	report.Pressure = collectAgentPressure()
+	report.OOMKills = cachedAgentOOMKills()
 	if data, err := os.ReadFile("/proc/meminfo"); err == nil {
 		values := map[string]uint64{}
 		for _, line := range strings.Split(string(data), "\n") {
@@ -494,6 +534,10 @@ func collectAgentReport() AgentReport {
 		if report.MemoryTotal > available {
 			report.MemoryUsed = report.MemoryTotal - available
 		}
+		report.SwapTotal = values["SwapTotal"]
+		if report.SwapTotal > values["SwapFree"] {
+			report.SwapUsed = report.SwapTotal - values["SwapFree"]
+		}
 	}
 	var stat syscall.Statfs_t
 	if syscall.Statfs("/", &stat) == nil {
@@ -507,6 +551,7 @@ func collectAgentReport() AgentReport {
 	report.DockerAvailable = report.DockerError == ""
 	inventory := cachedAgentInventory()
 	report.OSName, report.Kernel, report.Services = inventory.OSName, inventory.Kernel, inventory.Services
+	report.Issues = cachedAgentIssues()
 	report.UpdatesAvailable, report.RebootRequired, report.InventoryAt = inventory.UpdatesAvailable, inventory.RebootRequired, inventory.CollectedAt.Unix()
 	return report
 }
@@ -554,6 +599,16 @@ func cachedAgentInventory() agentInventory {
 	return value
 }
 
+func cachedAgentIssues() []AgentIssue {
+	guestIssues.Lock()
+	defer guestIssues.Unlock()
+	if time.Since(guestIssues.collectedAt) >= time.Minute {
+		guestIssues.value = collectAgentIssues()
+		guestIssues.collectedAt = time.Now()
+	}
+	return guestIssues.value
+}
+
 func readOSPrettyName() string {
 	data, err := os.ReadFile("/etc/os-release")
 	if err != nil {
@@ -571,7 +626,7 @@ func runAgentCommand(timeout time.Duration, name string, args ...string) string
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
 	output, err := exec.CommandContext(ctx, name, args...).Output()
-	if err != nil {
+	if err != nil && len(output) == 0 {
 		return ""
 	}
 	return string(output)
@@ -594,10 +649,149 @@ func collectAgentServices() []AgentService {
 			description = strings.Join(fields[offset+4:], " ")
 		}
 		result = append(result, AgentService{Name: fields[offset], State: fields[offset+2], SubState: fields[offset+3], Description: description})
-		if len(result) >= 150 {
+		if len(result) >= 300 {
 			break
 		}
 	}
+	return enrichAgentServices(result)
+}
+
+func enrichAgentServices(services []AgentService) []AgentService {
+	if len(services) == 0 {
+		return services
+	}
+	args := []string{"show", "--no-pager", "--property=Id", "--property=FragmentPath", "--property=NRestarts", "--property=ExecMainStatus", "--property=ActiveEnterTimestampUSec", "--property=MemoryCurrent", "--property=CPUUsageNSec", "--property=MainPID", "--property=ExecStart", "--property=Requires", "--property=After"}
+	for _, service := range services {
+		args = append(args, service.Name)
+	}
+	show := runAgentCommand(8*time.Second, "systemctl", args...)
+	properties := map[string]map[string]string{}
+	paths := map[string]string{}
+	for _, record := range strings.Split(show, "\n\n") {
+		values := map[string]string{}
+		for _, line := range strings.Split(record, "\n") {
+			key, value, ok := strings.Cut(line, "=")
+			if ok {
+				values[key] = value
+			}
+		}
+		if id := values["Id"]; id != "" {
+			properties[id] = values
+			paths[id] = values["FragmentPath"]
+		}
+	}
+	pathArgs := []string{"-S"}
+	for _, service := range services {
+		if path := paths[service.Name]; path != "" {
+			pathArgs = append(pathArgs, path)
+		}
+	}
+	owners := map[string]string{}
+	packages := []string{}
+	if len(pathArgs) > 1 {
+		output := runAgentCommand(8*time.Second, "dpkg-query", pathArgs...)
+		for _, line := range strings.Split(output, "\n") {
+			left, path, ok := strings.Cut(line, ": ")
+			if !ok {
+				continue
+			}
+			pkg := strings.TrimSpace(strings.Split(left, ",")[0])
+			path = strings.TrimSpace(path)
+			if pkg != "" && path != "" {
+				owners[path] = pkg
+				packages = append(packages, pkg)
+			}
+		}
+	}
+	priorities := map[string]string{}
+	if len(packages) > 0 {
+		packageArgs := []string{"-W", "-f=${binary:Package}\t${Priority}\n"}
+		packageArgs = append(packageArgs, packages...)
+		output := runAgentCommand(8*time.Second, "dpkg-query", packageArgs...)
+		for _, line := range strings.Split(output, "\n") {
+			fields := strings.Fields(line)
+			if len(fields) >= 2 {
+				priorities[fields[0]] = fields[1]
+			}
+		}
+	}
+	for i := range services {
+		service := &services[i]
+		service.UnitPath = paths[service.Name]
+		service.Package = owners[service.UnitPath]
+		service.Origin = classifyAgentService(service.UnitPath, service.Package, priorities[service.Package])
+		values := properties[service.Name]
+		service.Restarts, _ = strconv.ParseUint(values["NRestarts"], 10, 64)
+		exit, _ := strconv.ParseInt(values["ExecMainStatus"], 10, 32)
+		service.ExitCode = int(exit)
+		started, _ := strconv.ParseInt(values["ActiveEnterTimestampUSec"], 10, 64)
+		service.StartedAt = started / 1_000_000
+		service.MemoryBytes, _ = strconv.ParseUint(values["MemoryCurrent"], 10, 64)
+		cpu, _ := strconv.ParseUint(values["CPUUsageNSec"], 10, 64)
+		service.CPUSeconds = float64(cpu) / 1_000_000_000
+		pid, _ := strconv.Atoi(values["MainPID"])
+		service.MainPID = pid
+		service.ExecStart = compactSystemdExec(values["ExecStart"])
+		service.Requires = limitedFields(values["Requires"], 12)
+		service.After = limitedFields(values["After"], 12)
+		service.Flapping = service.Restarts >= 5 && service.StartedAt > time.Now().Add(-10*time.Minute).Unix()
+		if service.State == "failed" || service.SubState == "failed" || service.Flapping {
+			service.Logs = collectAgentJournal(service.Name, 8, "-2h")
+		}
+	}
+	ports := collectAgentListenPorts()
+	for i := range services {
+		for _, port := range ports {
+			if services[i].MainPID > 0 && port.PID == services[i].MainPID {
+				services[i].ListenPorts = appendUniqueInt(services[i].ListenPorts, port.Port)
+			}
+		}
+	}
+	return services
+}
+
+func classifyAgentService(path, pkg, priority string) string {
+	switch {
+	case strings.HasPrefix(path, "/etc/systemd/") || strings.HasPrefix(path, "/usr/local/"):
+		return "local"
+	case priority == "required" || priority == "important" || priority == "standard":
+		return "system"
+	case pkg != "":
+		return "added"
+	case strings.HasPrefix(path, "/run/systemd/"):
+		return "runtime"
+	default:
+		return "system"
+	}
+}
+
+func collectAgentIssues() []AgentIssue {
+	output := runAgentCommand(8*time.Second, "journalctl", "-p", "err..alert", "--since", "24 hours ago", "--reverse", "-n", "50", "--no-pager", "-o", "json")
+	return parseAgentIssues(output)
+}
+
+func parseAgentIssues(output string) []AgentIssue {
+	result := []AgentIssue{}
+	for _, line := range strings.Split(output, "\n") {
+		var entry struct {
+			Message   any    `json:"MESSAGE"`
+			Unit      string `json:"_SYSTEMD_UNIT"`
+			Timestamp string `json:"__REALTIME_TIMESTAMP"`
+		}
+		if json.Unmarshal([]byte(line), &entry) != nil {
+			continue
+		}
+		message, ok := entry.Message.(string)
+		if !ok || strings.TrimSpace(message) == "" {
+			continue
+		}
+		microseconds, _ := strconv.ParseInt(entry.Timestamp, 10, 64)
+		unit := entry.Unit
+		if unit == "" {
+			unit = "system"
+		}
+		result = append(result, AgentIssue{Time: microseconds / 1_000_000, Unit: unit, Message: message})
+	}
 	return result
 }
 

agent_diagnostics.go

@@ -0,0 +1,329 @@
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"net"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+)
+
+type AgentLog struct {
+	Time    int64  `json:"time"`
+	Message string `json:"message"`
+}
+
+type AgentProcess struct {
+	PID         int     `json:"pid"`
+	Name        string  `json:"name"`
+	State       string  `json:"state"`
+	CPUPercent  float64 `json:"cpuPercent"`
+	MemoryBytes uint64  `json:"memoryBytes"`
+	ReadBytes   uint64  `json:"readBytes"`
+	WriteBytes  uint64  `json:"writeBytes"`
+	Elapsed     int64   `json:"elapsedSeconds"`
+	Command     string  `json:"command"`
+}
+
+type AgentFilesystem struct {
+	Device        string  `json:"device"`
+	Mountpoint    string  `json:"mountpoint"`
+	Type          string  `json:"type"`
+	TotalBytes    uint64  `json:"totalBytes"`
+	UsedBytes     uint64  `json:"usedBytes"`
+	UsedPercent   float64 `json:"usedPercent"`
+	InodesTotal   uint64  `json:"inodesTotal"`
+	InodesUsed    uint64  `json:"inodesUsed"`
+	InodesPercent float64 `json:"inodesPercent"`
+}
+
+type AgentListenPort struct {
+	Protocol string `json:"protocol"`
+	Address  string `json:"address"`
+	Port     int    `json:"port"`
+	PID      int    `json:"pid,omitempty"`
+	Process  string `json:"process,omitempty"`
+}
+
+type AgentPressureValue struct {
+	Avg10  float64 `json:"avg10"`
+	Avg60  float64 `json:"avg60"`
+	Avg300 float64 `json:"avg300"`
+}
+
+type AgentPressure struct {
+	CPU    AgentPressureValue `json:"cpu"`
+	Memory AgentPressureValue `json:"memory"`
+	IO     AgentPressureValue `json:"io"`
+}
+
+var agentOOMCache struct {
+	sync.Mutex
+	value []AgentLog
+	at    time.Time
+}
+
+func compactSystemdExec(value string) string {
+	if pathAt := strings.Index(value, "path="); pathAt >= 0 {
+		value = value[pathAt+5:]
+	}
+	if end := strings.IndexAny(value, " ;}"); end > 0 {
+		value = value[:end]
+	}
+	if len(value) > 240 {
+		value = value[:240]
+	}
+	return strings.TrimSpace(value)
+}
+
+func limitedFields(value string, limit int) []string {
+	fields := strings.Fields(value)
+	if len(fields) > limit {
+		fields = fields[:limit]
+	}
+	return fields
+}
+
+func appendUniqueInt(items []int, value int) []int {
+	for _, item := range items {
+		if item == value {
+			return items
+		}
+	}
+	return append(items, value)
+}
+
+func collectAgentJournal(unit string, limit int, since string) []AgentLog {
+	args := []string{"--no-pager", "-o", "json", "--reverse", "-n", strconv.Itoa(limit), "--since", since}
+	if unit != "" {
+		args = append(args, "-u", unit)
+	}
+	output := runAgentCommand(6*time.Second, "journalctl", args...)
+	result := []AgentLog{}
+	for _, line := range strings.Split(output, "\n") {
+		var entry struct {
+			Message   any    `json:"MESSAGE"`
+			Timestamp string `json:"__REALTIME_TIMESTAMP"`
+		}
+		if json.Unmarshal([]byte(line), &entry) != nil {
+			continue
+		}
+		message, ok := entry.Message.(string)
+		if !ok || strings.TrimSpace(message) == "" {
+			continue
+		}
+		microseconds, _ := strconv.ParseInt(entry.Timestamp, 10, 64)
+		result = append(result, AgentLog{Time: microseconds / 1_000_000, Message: message})
+	}
+	return result
+}
+
+func cachedAgentOOMKills() []AgentLog {
+	agentOOMCache.Lock()
+	defer agentOOMCache.Unlock()
+	if time.Since(agentOOMCache.at) < time.Minute {
+		return agentOOMCache.value
+	}
+	output := runAgentCommand(6*time.Second, "journalctl", "-k", "--since", "24 hours ago", "--reverse", "--no-pager", "-o", "json", "-g", "Out of memory|Killed process")
+	result := []AgentLog{}
+	for _, line := range strings.Split(output, "\n") {
+		var entry struct {
+			Message   any    `json:"MESSAGE"`
+			Timestamp string `json:"__REALTIME_TIMESTAMP"`
+		}
+		if json.Unmarshal([]byte(line), &entry) != nil {
+			continue
+		}
+		message, ok := entry.Message.(string)
+		if !ok {
+			continue
+		}
+		microseconds, _ := strconv.ParseInt(entry.Timestamp, 10, 64)
+		result = append(result, AgentLog{Time: microseconds / 1_000_000, Message: message})
+		if len(result) >= 20 {
+			break
+		}
+	}
+	agentOOMCache.value, agentOOMCache.at = result, time.Now()
+	return result
+}
+
+func collectAgentProcesses() []AgentProcess {
+	result := []AgentProcess{}
+	seen := map[int]bool{}
+	for _, sortBy := range []string{"-pcpu", "-rss"} {
+		output := runAgentCommand(5*time.Second, "ps", "-eo", "pid=,comm=,state=,pcpu=,rss=,etimes=,args=", "--sort="+sortBy)
+		added := 0
+		for _, line := range strings.Split(output, "\n") {
+			fields := strings.Fields(line)
+			if len(fields) < 7 {
+				continue
+			}
+			pid, err := strconv.Atoi(fields[0])
+			if err != nil || seen[pid] {
+				continue
+			}
+			seen[pid] = true
+			cpu, _ := strconv.ParseFloat(fields[3], 64)
+			rss, _ := strconv.ParseUint(fields[4], 10, 64)
+			elapsed, _ := strconv.ParseInt(fields[5], 10, 64)
+			item := AgentProcess{PID: pid, Name: fields[1], State: fields[2], CPUPercent: cpu, MemoryBytes: rss * 1024, Elapsed: elapsed, Command: strings.Join(fields[6:], " ")}
+			item.ReadBytes, item.WriteBytes = readAgentProcessIO(pid)
+			result = append(result, item)
+			added++
+			if added >= 12 || len(result) >= 24 {
+				break
+			}
+		}
+	}
+	return result
+}
+
+func readAgentProcessIO(pid int) (uint64, uint64) {
+	data, err := os.ReadFile(filepath.Join("/proc", strconv.Itoa(pid), "io"))
+	if err != nil {
+		return 0, 0
+	}
+	values := map[string]uint64{}
+	for _, line := range strings.Split(string(data), "\n") {
+		fields := strings.Fields(line)
+		if len(fields) != 2 {
+			continue
+		}
+		values[strings.TrimSuffix(fields[0], ":")], _ = strconv.ParseUint(fields[1], 10, 64)
+	}
+	return values["read_bytes"], values["write_bytes"]
+}
+
+func collectAgentFilesystems() []AgentFilesystem {
+	file, err := os.Open("/proc/self/mounts")
+	if err != nil {
+		return nil
+	}
+	defer file.Close()
+	excluded := map[string]bool{"proc": true, "sysfs": true, "devtmpfs": true, "devpts": true, "tmpfs": true, "cgroup": true, "cgroup2": true, "overlay": true, "squashfs": true, "nsfs": true, "tracefs": true, "debugfs": true, "securityfs": true, "pstore": true, "mqueue": true, "hugetlbfs": true, "fusectl": true, "configfs": true, "autofs": true, "rpc_pipefs": true}
+	seen := map[string]bool{}
+	result := []AgentFilesystem{}
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 3 || excluded[fields[2]] || seen[fields[1]] {
+			continue
+		}
+		mountpoint := strings.ReplaceAll(fields[1], `\040`, " ")
+		var stat syscall.Statfs_t
+		if syscall.Statfs(mountpoint, &stat) != nil || stat.Blocks == 0 {
+			continue
+		}
+		seen[mountpoint] = true
+		total := stat.Blocks * uint64(stat.Bsize)
+		free := stat.Bavail * uint64(stat.Bsize)
+		used := total - free
+		item := AgentFilesystem{Device: fields[0], Mountpoint: mountpoint, Type: fields[2], TotalBytes: total, UsedBytes: used, UsedPercent: float64(used) / float64(total) * 100, InodesTotal: stat.Files}
+		if stat.Files > stat.Ffree {
+			item.InodesUsed = stat.Files - stat.Ffree
+			item.InodesPercent = float64(item.InodesUsed) / float64(stat.Files) * 100
+		}
+		result = append(result, item)
+		if len(result) >= 30 {
+			break
+		}
+	}
+	sort.Slice(result, func(i, j int) bool { return result[i].Mountpoint < result[j].Mountpoint })
+	return result
+}
+
+var ssPIDPattern = regexp.MustCompile(`pid=([0-9]+)`)
+var ssNamePattern = regexp.MustCompile(`users:\(\(\"([^\"]+)\"`)
+
+func collectAgentListenPorts() []AgentListenPort {
+	output := runAgentCommand(5*time.Second, "ss", "-H", "-lntup")
+	result := []AgentListenPort{}
+	seen := map[string]bool{}
+	for _, line := range strings.Split(output, "\n") {
+		fields := strings.Fields(line)
+		if len(fields) < 5 {
+			continue
+		}
+		protocol := strings.ToLower(fields[0])
+		local := ""
+		for _, field := range fields[1:] {
+			if strings.Contains(field, ":") && !strings.Contains(field, "users:") {
+				local = field
+				break
+			}
+		}
+		if local == "" {
+			continue
+		}
+		address, portText, err := net.SplitHostPort(local)
+		if err != nil {
+			idx := strings.LastIndex(local, ":")
+			if idx < 0 {
+				continue
+			}
+			address, portText = local[:idx], local[idx+1:]
+		}
+		port, _ := strconv.Atoi(portText)
+		if port <= 0 {
+			continue
+		}
+		pid := 0
+		if match := ssPIDPattern.FindStringSubmatch(line); len(match) > 1 {
+			pid, _ = strconv.Atoi(match[1])
+		}
+		process := ""
+		if match := ssNamePattern.FindStringSubmatch(line); len(match) > 1 {
+			process = match[1]
+		}
+		key := protocol + "|" + address + "|" + portText + "|" + strconv.Itoa(pid)
+		if seen[key] {
+			continue
+		}
+		seen[key] = true
+		result = append(result, AgentListenPort{Protocol: protocol, Address: address, Port: port, PID: pid, Process: process})
+	}
+	sort.Slice(result, func(i, j int) bool {
+		if result[i].Port == result[j].Port {
+			return result[i].Protocol < result[j].Protocol
+		}
+		return result[i].Port < result[j].Port
+	})
+	return result
+}
+
+func collectAgentPressure() AgentPressure {
+	return AgentPressure{CPU: readPressure("/proc/pressure/cpu"), Memory: readPressure("/proc/pressure/memory"), IO: readPressure("/proc/pressure/io")}
+}
+
+func readPressure(path string) AgentPressureValue {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return AgentPressureValue{}
+	}
+	line := strings.SplitN(string(data), "\n", 2)[0]
+	value := AgentPressureValue{}
+	for _, field := range strings.Fields(line) {
+		key, raw, ok := strings.Cut(field, "=")
+		if !ok {
+			continue
+		}
+		number, _ := strconv.ParseFloat(raw, 64)
+		switch key {
+		case "avg10":
+			value.Avg10 = number
+		case "avg60":
+			value.Avg60 = number
+		case "avg300":
+			value.Avg300 = number
+		}
+	}
+	return value
+}

agent_test.go

@@ -53,6 +53,37 @@ func TestAgentOnlyInstallsNewerVersion(t *testing.T) {
 	}
 }
 
+func TestParseAgentIssues(t *testing.T) {
+	issues := parseAgentIssues(`{"MESSAGE":"disk error","_SYSTEMD_UNIT":"worker.service","__REALTIME_TIMESTAMP":"1722960000000000"}` + "\n" + `{"MESSAGE":"network error","__REALTIME_TIMESTAMP":"1722960001000000"}`)
+	if len(issues) != 2 || issues[0].Unit != "worker.service" || issues[1].Unit != "system" || issues[0].Time != 1722960000 {
+		t.Fatalf("unexpected issues: %#v", issues)
+	}
+}
+
+func TestClassifyAgentService(t *testing.T) {
+	cases := []struct{ path, pkg, priority, want string }{{"/lib/systemd/system/cron.service", "cron", "important", "system"}, {"/lib/systemd/system/jellyfin.service", "jellyfin", "optional", "added"}, {"/etc/systemd/system/my.service", "", "", "local"}, {"/run/systemd/system/transient.service", "", "", "runtime"}}
+	for _, tc := range cases {
+		if got := classifyAgentService(tc.path, tc.pkg, tc.priority); got != tc.want {
+			t.Errorf("%s: got %s want %s", tc.path, got, tc.want)
+		}
+	}
+}
+
+func TestAgentServiceDiagnosticsHelpers(t *testing.T) {
+	if got := compactSystemdExec(`{ path=/usr/bin/example ; argv[]=/usr/bin/example --serve ; }`); got != "/usr/bin/example" {
+		t.Fatalf("unexpected executable: %q", got)
+	}
+	fields := limitedFields("a b c d", 2)
+	if len(fields) != 2 || fields[0] != "a" || fields[1] != "b" {
+		t.Fatalf("unexpected limited fields: %#v", fields)
+	}
+	ports := appendUniqueInt([]int{80}, 80)
+	ports = appendUniqueInt(ports, 443)
+	if len(ports) != 2 || ports[1] != 443 {
+		t.Fatalf("unexpected ports: %#v", ports)
+	}
+}
+
 func TestAgentReportAuthenticationAndOfflineState(t *testing.T) {
 	store, err := openStore(":memory:")
 	if err != nil {
@@ -94,3 +125,22 @@ func TestAgentProblemsBecomeMaintenanceAwareAlerts(t *testing.T) {
 		t.Fatalf("active=%d planned=%d alerts=%#v", len(active), len(planned), alerts)
 	}
 }
+
+func TestAgentDiagnosticsBecomeAlerts(t *testing.T) {
+	metrics := dashboardMetrics{Agents: []ManagedAgent{{ID: "node", Name: "app", VMID: 105, Online: true, Report: AgentReport{
+		Services:    []AgentService{{Name: "web.service", State: "active", Flapping: true, Restarts: 8, StartedAt: time.Now().Unix()}},
+		Filesystems: []AgentFilesystem{{Mountpoint: "/data", TotalBytes: 1000, UsedBytes: 950, UsedPercent: 95}},
+	}}}}
+	alerts := evaluateAlerts(metrics, defaultThresholds())
+	wanted := map[string]bool{"agent-flapping-node-web.service-105": false, "agent-filesystem-node-/data-105": false}
+	for _, alert := range alerts {
+		if _, ok := wanted[alert.ID]; ok {
+			wanted[alert.ID] = true
+		}
+	}
+	for id, found := range wanted {
+		if !found {
+			t.Fatalf("missing alert %s in %#v", id, alerts)
+		}
+	}
+}

alerts.go

@@ -215,8 +215,22 @@ func evaluateAlerts(metrics dashboardMetrics, thresholds AlertThresholds) []Aler
 		for _, service := range agent.Report.Services {
 			if service.State == "failed" || service.SubState == "failed" {
 				add("agent-systemd-"+agent.ID+"-"+service.Name+vmSuffix, "critical", "Агенты", agent.Name+": упала служба "+service.Name, fmt.Sprintf("%s · VMID %d.", firstNonEmpty(service.Description, service.SubState), agent.VMID))
+			} else if service.Flapping {
+				add("agent-flapping-"+agent.ID+"-"+service.Name+vmSuffix, "warning", "Агенты", agent.Name+": служба постоянно перезапускается", fmt.Sprintf("%s: %d рестартов, последний запуск %s · VMID %d.", service.Name, service.Restarts, time.Unix(service.StartedAt, 0).Format("15:04:05"), agent.VMID))
 			}
 		}
+		for _, filesystem := range agent.Report.Filesystems {
+			if filesystem.UsedPercent >= 90 {
+				add("agent-filesystem-"+agent.ID+"-"+filesystem.Mountpoint+vmSuffix, "critical", "Агенты", agent.Name+": заканчивается место "+filesystem.Mountpoint, fmt.Sprintf("Заполнено %.1f%%, свободно %.1f GB · VMID %d.", filesystem.UsedPercent, float64(filesystem.TotalBytes-filesystem.UsedBytes)/1073741824, agent.VMID))
+			}
+			if filesystem.InodesPercent >= 90 {
+				add("agent-inodes-"+agent.ID+"-"+filesystem.Mountpoint+vmSuffix, "critical", "Агенты", agent.Name+": заканчиваются inode "+filesystem.Mountpoint, fmt.Sprintf("Использовано %.1f%% inode · VMID %d.", filesystem.InodesPercent, agent.VMID))
+			}
+		}
+		if len(agent.Report.OOMKills) > 0 {
+			latest := agent.Report.OOMKills[0]
+			add("agent-oom-"+agent.ID+vmSuffix, "critical", "Агенты", agent.Name+": ядро завершало процессы из-за нехватки памяти", fmt.Sprintf("%s · %s · VMID %d.", time.Unix(latest.Time, 0).Format("02.01 15:04"), latest.Message, agent.VMID))
+		}
 		if agent.Report.RebootRequired {
 			add("agent-reboot-"+agent.ID+vmSuffix, "info", "Агенты", agent.Name+": требуется перезагрузка", fmt.Sprintf("Обновления системы запросили перезагрузку · VMID %d.", agent.VMID))
 		}