feat: add proxy and statistics features

server/internal/api/handlers.go

@@ -124,7 +124,7 @@ func (h *Handler) ListContainers(w http.ResponseWriter, r *http.Request) {
 		IPAddress string                 `json:"ip_address"`
 		Container *agentv1.ContainerInfo `json:"container"`
 	}
-	var out []containerDTO
+	out := make([]containerDTO, 0)
 	for _, agent := range h.registry.List() {
 		for _, c := range agent.Containers {
 			out = append(out, containerDTO{
@@ -193,7 +193,7 @@ func (h *Handler) ListImages(w http.ResponseWriter, r *http.Request) {
 		CreatedAt int64    `json:"created_at"`
 		IsOrphan  bool     `json:"is_orphan"`
 	}
-	var out []imageDTO
+	out := make([]imageDTO, 0)
 	for _, agent := range h.registry.List() {
 		for _, img := range agent.Images {
 			out = append(out, imageDTO{
@@ -247,7 +247,7 @@ func (h *Handler) ListVolumes(w http.ResponseWriter, r *http.Request) {
 		Mountpoint string `json:"mountpoint"`
 		IsOrphan   bool   `json:"is_orphan"`
 	}
-	var out []volumeDTO
+	out := make([]volumeDTO, 0)
 	for _, agent := range h.registry.List() {
 		for _, vol := range agent.Volumes {
 			out = append(out, volumeDTO{
@@ -301,7 +301,7 @@ func (h *Handler) ListNetworks(w http.ResponseWriter, r *http.Request) {
 		Scope     string `json:"scope"`
 		IsOrphan  bool   `json:"is_orphan"`
 	}
-	var out []networkDTO
+	out := make([]networkDTO, 0)
 	for _, agent := range h.registry.List() {
 		for _, net := range agent.Networks {
 			out = append(out, networkDTO{
@@ -753,6 +753,129 @@ func (h *Handler) UpdateNow(w http.ResponseWriter, r *http.Request) {
 	jsonOK(w, map[string]string{"command_id": cmdID})
 }
 
+// ── Stats ─────────────────────────────────────────────────────────────────────
+
+type processDTO struct {
+	Pid    uint32  `json:"pid"`
+	Name   string  `json:"name"`
+	Cmd    string  `json:"cmd"`
+	CpuPct float64 `json:"cpu_pct"`
+	MemRss uint64  `json:"mem_rss"`
+}
+
+type netIfaceDTO struct {
+	Name          string `json:"name"`
+	BytesRecv     uint64 `json:"bytes_recv"`
+	BytesSent     uint64 `json:"bytes_sent"`
+	BytesRecvRate uint64 `json:"bytes_recv_rate"`
+	BytesSentRate uint64 `json:"bytes_sent_rate"`
+}
+
+type diskDTO struct {
+	Path  string `json:"path"`
+	Total uint64 `json:"total"`
+	Used  uint64 `json:"used"`
+	Free  uint64 `json:"free"`
+}
+
+type statsSnapshotDTO struct {
+	CpuPct        float64       `json:"cpu_pct"`
+	CpuPerCore    []float64     `json:"cpu_per_core"`
+	MemTotal      uint64        `json:"mem_total"`
+	MemUsed       uint64        `json:"mem_used"`
+	MemAvailable  uint64        `json:"mem_available"`
+	NetInterfaces []netIfaceDTO `json:"net_interfaces"`
+	Processes     []processDTO  `json:"processes"`
+	Disks         []diskDTO     `json:"disks"`
+	Timestamp     int64         `json:"timestamp"`
+}
+
+func protoStatsToDTO(s *agentv1.StatsSnapshot) *statsSnapshotDTO {
+	if s == nil {
+		return nil
+	}
+	dto := &statsSnapshotDTO{
+		CpuPct:       s.CpuPct,
+		CpuPerCore:   s.CpuPerCore,
+		MemTotal:     s.MemTotal,
+		MemUsed:      s.MemUsed,
+		MemAvailable: s.MemAvailable,
+		Timestamp:    s.Timestamp,
+	}
+	if dto.CpuPerCore == nil {
+		dto.CpuPerCore = []float64{}
+	}
+	for _, iface := range s.NetInterfaces {
+		dto.NetInterfaces = append(dto.NetInterfaces, netIfaceDTO{
+			Name:          iface.Name,
+			BytesRecv:     iface.BytesRecv,
+			BytesSent:     iface.BytesSent,
+			BytesRecvRate: iface.BytesRecvRate,
+			BytesSentRate: iface.BytesSentRate,
+		})
+	}
+	if dto.NetInterfaces == nil {
+		dto.NetInterfaces = []netIfaceDTO{}
+	}
+	for _, p := range s.Processes {
+		dto.Processes = append(dto.Processes, processDTO{
+			Pid:    p.Pid,
+			Name:   p.Name,
+			Cmd:    p.Cmd,
+			CpuPct: p.CpuPct,
+			MemRss: p.MemRss,
+		})
+	}
+	if dto.Processes == nil {
+		dto.Processes = []processDTO{}
+	}
+	for _, d := range s.Disks {
+		dto.Disks = append(dto.Disks, diskDTO{
+			Path:  d.Path,
+			Total: d.Total,
+			Used:  d.Used,
+			Free:  d.Free,
+		})
+	}
+	if dto.Disks == nil {
+		dto.Disks = []diskDTO{}
+	}
+	return dto
+}
+
+// ListStats handles GET /api/v1/stats — returns system stats for all connected agents.
+func (h *Handler) ListStats(w http.ResponseWriter, r *http.Request) {
+	type statsDTO struct {
+		AgentID   string            `json:"agent_id"`
+		Hostname  string            `json:"hostname"`
+		Alias     string            `json:"alias"`
+		IPAddress string            `json:"ip_address"`
+		Stats     *statsSnapshotDTO `json:"stats"`
+	}
+	out := make([]statsDTO, 0)
+	for _, agent := range h.registry.List() {
+		out = append(out, statsDTO{
+			AgentID:   agent.ID,
+			Hostname:  agent.Hostname,
+			Alias:     agent.Alias,
+			IPAddress: agent.IPAddress,
+			Stats:     protoStatsToDTO(agent.Stats),
+		})
+	}
+	jsonOK(w, out)
+}
+
+// GetAgentStats handles GET /api/v1/agents/{agentID}/stats — returns stats for a single agent.
+func (h *Handler) GetAgentStats(w http.ResponseWriter, r *http.Request) {
+	agentID := chi.URLParam(r, "agentID")
+	state, ok := h.registry.Get(agentID)
+	if !ok {
+		http.Error(w, "agent not connected", http.StatusNotFound)
+		return
+	}
+	jsonOK(w, protoStatsToDTO(state.Stats))
+}
+
 func jsonOK(w http.ResponseWriter, v any) {
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(v)