feat: big ahh commit

- agent+proto+backend: transfer service status
- agent: fix returning empty message on nonzero exit status
- backend: refactor collector+commander and handlers dependent on them: implement agent accounting via grpc stats handler

backend/internal/grpcsrv/collector/collector.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"io"
 	"log"
-	"sync"
 	"time"
 
 	"gitea.d3m0k1d.ru/d3m0k1d/HellreigN/backend/internal/repository"
@@ -13,26 +12,19 @@ import (
 	"google.golang.org/grpc/metadata"
 )
 
+// Collector handles log streaming from connected agents.
 type Collector struct {
 	proto.UnimplementedCollectorServer
 	logRepo       *repository.LogRepository
-	agents        map[string]*Agent
-	mu            sync.RWMutex
+	tracker       *ConnTracker
 	batchSize     int
 	flushInterval time.Duration
 }
 
-type Agent struct {
-	ID          string
-	Label       string
-	Services    []string
-	ConnectedAt time.Time
-}
-
-func New(logRepo *repository.LogRepository) *Collector {
+func New(logRepo *repository.LogRepository, tracker *ConnTracker) *Collector {
 	return &Collector{
 		logRepo:       logRepo,
-		agents:        make(map[string]*Agent),
+		tracker:       tracker,
 		batchSize:     100,
 		flushInterval: 2 * time.Second,
 	}
@@ -56,27 +48,15 @@ func (c *Collector) Stream(stream proto.Collector_StreamServer) error {
 	}
 	service := serviceVals[0]
 
-	servicesVals := md["services"]
-	var services []string
-	if len(servicesVals) > 0 {
-		services = servicesVals
-	}
-
-	// Register agent
-	c.mu.Lock()
-	c.agents[agentName] = &Agent{
+	agent := &Agent{
 		ID:          agentName,
 		Label:       agentName,
-		Services:    services,
+		Services:    make([]Service, 0),
 		ConnectedAt: time.Now(),
 	}
-	c.mu.Unlock()
 
-	defer func() {
-		c.mu.Lock()
-		delete(c.agents, agentName)
-		c.mu.Unlock()
-	}()
+	c.tracker.Register(agent)
+	defer c.tracker.Unregister(agent.ID)
 
 	log.Printf("Agent %s connected, streaming logs for service: %s", agentName, service)
 
@@ -139,7 +119,6 @@ func (c *Collector) Stream(stream proto.Collector_StreamServer) error {
 	for {
 		select {
 		case <-stream.Context().Done():
-			// Context cancelled, flush remaining
 			_ = flush()
 			return stream.Context().Err()
 		case <-ticker.C:
@@ -162,7 +141,6 @@ func (c *Collector) Stream(stream proto.Collector_StreamServer) error {
 			}
 		case err := <-errCh:
 			if err == io.EOF {
-				// Client closed stream
 				return flush()
 			}
 			return fmt.Errorf("failed to receive: %w", err)
@@ -170,19 +148,12 @@ func (c *Collector) Stream(stream proto.Collector_StreamServer) error {
 	}
 }
 
+// GetAgent delegates to the tracker.
 func (c *Collector) GetAgent(name string) (*Agent, bool) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	a, ok := c.agents[name]
-	return a, ok
+	return c.tracker.GetAgent(name)
 }
 
+// Agents delegates to the tracker.
 func (c *Collector) Agents() []*Agent {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
-	result := make([]*Agent, 0, len(c.agents))
-	for _, a := range c.agents {
-		result = append(result, a)
-	}
-	return result
+	return c.tracker.Agents()
 }

backend/internal/grpcsrv/collector/services.go

@@ -0,0 +1,38 @@
+package collector
+
+import (
+	"context"
+	"fmt"
+	"log"
+
+	"gitea.d3m0k1d.ru/d3m0k1d/HellreigN/proto/proto"
+	"google.golang.org/grpc/metadata"
+)
+
+// ReportServices handles a unary service status update from an agent.
+// Agents send their current services list, which is stored in the collector.
+func (c *Collector) ReportServices(ctx context.Context, req *proto.ServicesUpdate) (*proto.ServicesUpdateResp, error) {
+	md, ok := metadata.FromIncomingContext(ctx)
+	if !ok {
+		return nil, fmt.Errorf("no metadata in context")
+	}
+
+	whoamiVals := md["whoami"]
+	if len(whoamiVals) == 0 {
+		return nil, fmt.Errorf("whoami metadata missing")
+	}
+	agentName := whoamiVals[0]
+
+	services := make([]Service, 0, len(req.Services))
+	for _, s := range req.Services {
+		services = append(services, Service{s.Name, s.Status})
+	}
+
+	if ok := c.tracker.UpdateServices(agentName, services); ok {
+		log.Printf("Updated services for agent %s: %v", agentName, services)
+	} else {
+		log.Printf("Warning: received services update for unknown agent %s", agentName)
+	}
+
+	return &proto.ServicesUpdateResp{}, nil
+}

backend/internal/grpcsrv/collector/tracker.go

@@ -0,0 +1,111 @@
+package collector
+
+import (
+	"context"
+	"log"
+	"sync"
+	"time"
+
+	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/stats"
+)
+
+// ConnTracker tracks connected Collector agents and handles cleanup on disconnect.
+// It implements grpc.StatsHandler for disconnect detection.
+type ConnTracker struct {
+	mu     sync.RWMutex
+	agents map[string]*Agent
+}
+
+func NewConnTracker() *ConnTracker {
+	return &ConnTracker{
+		agents: make(map[string]*Agent),
+	}
+}
+
+// Register adds an agent to the tracker. Called by Collector.Stream().
+func (t *ConnTracker) Register(agent *Agent) {
+	t.mu.Lock()
+	t.agents[agent.ID] = agent
+	t.mu.Unlock()
+	log.Printf("[collector] agent registered: %s", agent.ID)
+}
+
+// Unregister removes an agent from the tracker.
+func (t *ConnTracker) Unregister(id string) {
+	t.mu.Lock()
+	delete(t.agents, id)
+	t.mu.Unlock()
+	log.Printf("[collector] agent unregistered: %s", id)
+}
+
+// GetAgent returns the agent for the given ID.
+func (t *ConnTracker) GetAgent(id string) (*Agent, bool) {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	a, ok := t.agents[id]
+	return a, ok
+}
+
+// Agents returns all connected agents.
+func (t *ConnTracker) Agents() []*Agent {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+	result := make([]*Agent, 0, len(t.agents))
+	for _, a := range t.agents {
+		result = append(result, a)
+	}
+	return result
+}
+
+// grpc.StatsHandler implementation.
+
+func (t *ConnTracker) TagRPC(ctx context.Context, _ *stats.RPCTagInfo) context.Context {
+	return ctx
+}
+
+func (t *ConnTracker) HandleRPC(ctx context.Context, _ stats.RPCStats) {}
+
+func (t *ConnTracker) TagConn(ctx context.Context, _ *stats.ConnTagInfo) context.Context {
+	return ctx
+}
+
+func (t *ConnTracker) HandleConn(ctx context.Context, s stats.ConnStats) {
+	switch s.(type) {
+	case *stats.ConnEnd:
+		md, ok := metadata.FromIncomingContext(ctx)
+		if !ok {
+			return
+		}
+		whoamiVals := md["whoami"]
+		if len(whoamiVals) == 0 {
+			return
+		}
+		t.Unregister(whoamiVals[0])
+	}
+}
+
+// UpdateServices updates the services list for the given agent.
+func (t *ConnTracker) UpdateServices(id string, services []Service) bool {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	agent, ok := t.agents[id]
+	if !ok {
+		return false
+	}
+	agent.Services = services
+	return true
+}
+
+// Service represents a named service with its current status.
+type Service struct {
+	Name, Status string
+}
+
+// Agent represents a connected agent streaming logs to the collector.
+type Agent struct {
+	ID          string
+	Label       string
+	Services    []Service
+	ConnectedAt time.Time
+}