feat: add node agent system with heartbeat collection, installer generation, and traffic flow telemetry

Add NodeAgent and TrafficFlow models to track agent status and network flows, implement /agents/heartbeat endpoint to receive interface counters, conntrack flows, firewall status, and nftables ruleset hash from agents, add nexafabric-agent.py Python script to collect host telemetry including VM/LXC interface hints via tap/fwbr regex matching, conntrack flow parsing with protocol/state/byte counters, and pve-firewall status checks,

README.md

@@ -160,14 +160,41 @@ Actual traffic flow visibility, top talkers, byte counters, and per-workload tra
 
 Supported or planned options:
 
-- NexaFabric node agent on Proxmox nodes to read nftables/conntrack or flow counters.
+- NexaFabric node agent on Proxmox nodes to read host interface counters, VM/LXC interface hints, conntrack flows, nftables ruleset state, and pve-firewall status.
 - Open vSwitch with sFlow/NetFlow/IPFIX exported to a collector.
 - Router/firewall flow exports from pfSense, OPNsense, FRR/BGP edge devices, or physical switches.
 - eBPF or host-level telemetry in future agent builds.
 
 Until such a source is configured, NexaFabric will show `No flow telemetry collected yet` instead of fake traffic.
 
-### 8. Troubleshooting Proxmox Integration
+### 8. Install The Node Agent
+
+After a Proxmox cluster sync has imported nodes:
+
+1. Open `Nodes`.
+2. Click the agent icon on the node row.
+3. Copy the installer command.
+4. Run it as `root` on the matching Proxmox node.
+
+The installer creates:
+
+- `/opt/nexafabric-agent/nexafabric-agent.py`
+- `/etc/nexafabric-agent/config.json`
+- `nexafabric-agent.service`
+
+The agent sends a heartbeat every 30 seconds to NexaFabric. It uses a node-specific enrollment token generated by the UI and does not need your Proxmox API token.
+
+Useful commands on the Proxmox node:
+
+```bash
+systemctl status nexafabric-agent
+journalctl -u nexafabric-agent -f
+systemctl restart nexafabric-agent
+```
+
+The agent reports host/interface counters, VMID hints from Proxmox interface names, conntrack flow records, pve-firewall status, and an nftables ruleset hash. NexaFabric maps flow source/destination IPs back to workloads through IPAM, so VM/LXC details can show observed traffic once guest IPs have been discovered. The agent does not enforce policies itself; Proxmox firewall rule apply remains API-driven through NexaFabric.
+
+### 9. Troubleshooting Proxmox Integration
 
 `401 No ticket` or `Provider sync failed` usually means:
 

backend/app/agent_assets/nexafabric-agent.py

@@ -0,0 +1,210 @@
+#!/usr/bin/env python3
+import argparse
+import hashlib
+import json
+import os
+import platform
+import re
+import socket
+import ssl
+import subprocess
+import time
+import urllib.error
+import urllib.request
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any
+
+
+VERSION = "0.1.0"
+VM_INTERFACE_RE = re.compile(r"(?:tap|fwbr|fwln|fwpr)(\d+)")
+
+
+def read_text(path: str) -> str | None:
+    try:
+        return Path(path).read_text(encoding="utf-8").strip()
+    except OSError:
+        return None
+
+
+def run_command(args: list[str], timeout: int = 5) -> tuple[int, str]:
+    try:
+        result = subprocess.run(args, capture_output=True, text=True, timeout=timeout, check=False)
+        return result.returncode, result.stdout.strip()
+    except (OSError, subprocess.SubprocessError):
+        return 127, ""
+
+
+def collect_interfaces() -> list[dict[str, Any]]:
+    interfaces = []
+    for item in Path("/sys/class/net").iterdir() if Path("/sys/class/net").exists() else []:
+        name = item.name
+        if name == "lo":
+            continue
+        vm_match = VM_INTERFACE_RE.search(name)
+        interfaces.append(
+            {
+                "name": name,
+                "vmid": vm_match.group(1) if vm_match else None,
+                "operstate": read_text(f"/sys/class/net/{name}/operstate") or "unknown",
+                "rx_bytes": int(read_text(f"/sys/class/net/{name}/statistics/rx_bytes") or 0),
+                "tx_bytes": int(read_text(f"/sys/class/net/{name}/statistics/tx_bytes") or 0),
+                "rx_packets": int(read_text(f"/sys/class/net/{name}/statistics/rx_packets") or 0),
+                "tx_packets": int(read_text(f"/sys/class/net/{name}/statistics/tx_packets") or 0),
+            }
+        )
+    return interfaces
+
+
+def parse_conntrack_line(line: str) -> dict[str, Any] | None:
+    parts = line.split()
+    if len(parts) < 5 or parts[0] not in {"tcp", "udp", "icmp"}:
+        return None
+    protocol = parts[0]
+    state = None
+    if protocol == "tcp" and len(parts) > 3 and "=" not in parts[3]:
+        state = parts[3]
+
+    values: dict[str, list[str]] = {}
+    for part in parts:
+        if "=" not in part:
+            continue
+        key, value = part.split("=", 1)
+        values.setdefault(key, []).append(value)
+
+    src_values = values.get("src", [])
+    dst_values = values.get("dst", [])
+    if not src_values or not dst_values:
+        return None
+
+    packet_values = [int(value) for value in values.get("packets", []) if value.isdigit()]
+    byte_values = [int(value) for value in values.get("bytes", []) if value.isdigit()]
+    sport = values.get("sport", [None])[0]
+    dport = values.get("dport", [None])[0]
+    return {
+        "source_ip": src_values[0],
+        "destination_ip": dst_values[0],
+        "protocol": protocol,
+        "source_port": int(sport) if sport and sport.isdigit() else None,
+        "destination_port": int(dport) if dport and dport.isdigit() else None,
+        "packets": sum(packet_values),
+        "bytes": sum(byte_values),
+        "state": state,
+    }
+
+
+def collect_flows(limit: int = 500) -> list[dict[str, Any]]:
+    code, output = run_command(["conntrack", "-L", "-o", "extended"], timeout=10)
+    if code != 0 or not output:
+        return []
+    flows = []
+    seen = set()
+    for line in output.splitlines():
+        flow = parse_conntrack_line(line)
+        if not flow:
+            continue
+        key = (
+            flow["source_ip"],
+            flow["destination_ip"],
+            flow["protocol"],
+            flow.get("source_port"),
+            flow.get("destination_port"),
+        )
+        if key in seen:
+            continue
+        seen.add(key)
+        flows.append(flow)
+        if len(flows) >= limit:
+            break
+    return flows
+
+
+def collect_conntrack() -> dict[str, Any]:
+    code, output = run_command(["conntrack", "-C"])
+    if code == 0 and output.isdigit():
+        return {"count": int(output), "source": "conntrack"}
+    for path in ("/proc/net/nf_conntrack", "/proc/net/ip_conntrack"):
+        try:
+            with open(path, "r", encoding="utf-8", errors="ignore") as handle:
+                return {"count": sum(1 for _ in handle), "source": path}
+        except OSError:
+            continue
+    return {"count": None, "source": "unavailable"}
+
+
+def collect_firewall() -> dict[str, Any]:
+    status = {}
+    code, output = run_command(["systemctl", "is-active", "pve-firewall"])
+    status["pve_firewall"] = output if code == 0 else "unknown"
+    code, output = run_command(["nft", "-j", "list", "ruleset"], timeout=10)
+    if code == 0 and output:
+        status["nft_ruleset_sha256"] = hashlib.sha256(output.encode("utf-8")).hexdigest()
+    else:
+        status["nft_ruleset_sha256"] = None
+    return status
+
+
+def collect_payload(config: dict[str, Any]) -> dict[str, Any]:
+    uptime = read_text("/proc/uptime")
+    return {
+        "version": VERSION,
+        "node_name": config.get("node_name"),
+        "collected_at": datetime.now(timezone.utc).isoformat(),
+        "hostname": socket.gethostname(),
+        "kernel": platform.release(),
+        "uptime_seconds": float(uptime.split()[0]) if uptime else None,
+        "loadavg": list(os.getloadavg()) if hasattr(os, "getloadavg") else [],
+        "interfaces": collect_interfaces(),
+        "flows": collect_flows(int(config.get("flow_limit", 500))),
+        "conntrack": collect_conntrack(),
+        "firewall": collect_firewall(),
+        "extra": {"platform": platform.platform()},
+    }
+
+
+def post_heartbeat(config: dict[str, Any], payload: dict[str, Any]) -> None:
+    api_url = str(config["api_url"]).rstrip("/")
+    data = json.dumps(payload).encode("utf-8")
+    request = urllib.request.Request(
+        f"{api_url}/agents/heartbeat",
+        data=data,
+        headers={
+            "Authorization": f"Bearer {config['token']}",
+            "Content-Type": "application/json",
+            "User-Agent": f"nexafabric-agent/{VERSION}",
+        },
+        method="POST",
+    )
+    context = None
+    if not bool(config.get("verify_tls", True)):
+        context = ssl._create_unverified_context()
+    with urllib.request.urlopen(request, timeout=15, context=context) as response:
+        response.read()
+
+
+def load_config(path: str) -> dict[str, Any]:
+    return json.loads(Path(path).read_text(encoding="utf-8"))
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description="NexaFabric Proxmox node telemetry agent")
+    parser.add_argument("--config", default="/etc/nexafabric-agent/config.json")
+    parser.add_argument("--once", action="store_true")
+    args = parser.parse_args()
+    config = load_config(args.config)
+    interval = int(config.get("interval_seconds", 30))
+
+    while True:
+        payload = collect_payload(config)
+        try:
+            post_heartbeat(config, payload)
+            print(f"heartbeat ok: {payload['collected_at']}", flush=True)
+        except (OSError, urllib.error.URLError, urllib.error.HTTPError) as exc:
+            print(f"heartbeat failed: {exc}", flush=True)
+        if args.once:
+            return 0
+        time.sleep(interval)
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

backend/app/api/v1/router.py

@@ -1,10 +1,11 @@
-from datetime import datetime
+from datetime import datetime, timedelta
 import csv
 import io
 from ipaddress import ip_address, ip_interface, ip_network
+from pathlib import Path
 
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends, Header, HTTPException, Request
-from fastapi.responses import StreamingResponse
+from fastapi.responses import FileResponse, PlainTextResponse, StreamingResponse
 from sqlalchemy import func, select
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import Session
@@ -12,6 +13,7 @@ from sqlalchemy.orm import Session
 from app.api.deps import CurrentUser
 from app.api.v1 import auth
 from app.core.security import hash_password
+from app.core.security import create_token, decode_token
 from app.db.session import get_db
 from app.models.domain import (
     AuditLog,
@@ -20,6 +22,7 @@ from app.models.domain import (
     Job,
     Network,
     Node,
+    NodeAgent,
     Policy,
     Project,
     Role,
@@ -29,11 +32,13 @@ from app.models.domain import (
     SystemSetting,
     Subnet,
     Tenant,
+    TrafficFlow,
     User,
     Workload,
 )
 from app.schemas.domain import (
     AuditLogRead,
+    AgentHeartbeat,
     ClusterCreate,
     ClusterRead,
     ClusterUpdate,
@@ -45,6 +50,7 @@ from app.schemas.domain import (
     NetworkCreate,
     NetworkRead,
     NodeRead,
+    NodeWithAgentRead,
     PolicyCreate,
     PolicyRead,
     ProjectCreate,
@@ -233,6 +239,13 @@ def endpoint_values(db: Session, cluster: Cluster, ref: str) -> tuple[list[str |
     return [], [f"Endpoint {ref} is not yet resolvable to a Proxmox firewall matcher."]
 
 
+def flow_int(value: object, default: int = 0) -> int:
+    try:
+        return int(value) if value not in (None, "") else default
+    except (TypeError, ValueError):
+        return default
+
+
 def proxmox_action(action: str) -> str:
     return {"allow": "ACCEPT", "deny": "DROP", "reject": "REJECT"}.get(action, "ACCEPT")
 
@@ -489,6 +502,12 @@ def delete_cluster(cluster_id: str, user: CurrentUser, db: Session = Depends(get
                 db.delete(subnet)
         for network in db.scalars(select(Network).where(Network.id.in_(network_ids))).all():
             db.delete(network)
+    node_ids = [row[0] for row in db.execute(select(Node.id).where(Node.cluster_id == cluster.id)).all()]
+    if node_ids:
+        for agent in db.scalars(select(NodeAgent).where(NodeAgent.node_id.in_(node_ids))).all():
+            db.delete(agent)
+        for flow in db.scalars(select(TrafficFlow).where(TrafficFlow.node_id.in_(node_ids))).all():
+            db.delete(flow)
     for workload in db.scalars(select(Workload).where(Workload.cluster_id == cluster.id)).all():
         db.delete(workload)
     for node in db.scalars(select(Node).where(Node.cluster_id == cluster.id)).all():
@@ -618,6 +637,207 @@ def nodes(_: CurrentUser, db: Session = Depends(get_db)) -> list[Node]:
     return db.scalars(select(Node).order_by(Node.name)).all()
 
 
+def node_agent_payload(node: Node, agent: NodeAgent | None) -> dict:
+    return {
+        "id": node.id,
+        "cluster_id": node.cluster_id,
+        "name": node.name,
+        "status": node.status,
+        "cpu_count": node.cpu_count,
+        "memory_mb": node.memory_mb,
+        "agent": {
+            "node_id": agent.node_id,
+            "status": agent.status,
+            "version": agent.version,
+            "last_seen_at": agent.last_seen_at,
+            "install_count": agent.install_count,
+            "last_payload": agent.last_payload,
+        }
+        if agent
+        else None,
+    }
+
+
+@api_router.get("/nodes/agents", response_model=list[NodeWithAgentRead])
+def nodes_with_agents(_: CurrentUser, db: Session = Depends(get_db)) -> list[dict]:
+    agents = {agent.node_id: agent for agent in db.scalars(select(NodeAgent)).all()}
+    return [
+        node_agent_payload(node, agents.get(node.id))
+        for node in db.scalars(select(Node).order_by(Node.name)).all()
+    ]
+
+
+def agent_install_script(base_url: str, token: str, node: Node) -> str:
+    return f"""#!/bin/sh
+set -eu
+
+NEXAFABRIC_URL="${{NEXAFABRIC_URL:-{base_url.rstrip("/")}}}"
+INSTALL_DIR="${{INSTALL_DIR:-/opt/nexafabric-agent}}"
+CONFIG_DIR="${{CONFIG_DIR:-/etc/nexafabric-agent}}"
+SERVICE_NAME="${{SERVICE_NAME:-nexafabric-agent}}"
+
+if ! command -v python3 >/dev/null 2>&1; then
+  echo "python3 is required. Install python3 on this Proxmox node and run this script again." >&2
+  exit 1
+fi
+
+if ! command -v conntrack >/dev/null 2>&1 && command -v apt-get >/dev/null 2>&1; then
+  apt-get update
+  apt-get install -y conntrack
+fi
+
+mkdir -p "$INSTALL_DIR" "$CONFIG_DIR"
+curl -fsSL "$NEXAFABRIC_URL/api/v1/agents/download/nexafabric-agent.py" -o "$INSTALL_DIR/nexafabric-agent.py"
+chmod 0755 "$INSTALL_DIR/nexafabric-agent.py"
+
+cat > "$CONFIG_DIR/config.json" <<'JSON'
+{{
+  "api_url": "{base_url.rstrip("/")}/api/v1",
+  "token": "{token}",
+  "node_id": "{node.id}",
+  "node_name": "{node.name}",
+  "interval_seconds": 30,
+  "flow_limit": 500,
+  "verify_tls": true
+}}
+JSON
+chmod 0600 "$CONFIG_DIR/config.json"
+
+cat > "/etc/systemd/system/$SERVICE_NAME.service" <<EOF
+[Unit]
+Description=NexaFabric Node Agent
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/bin/python3 $INSTALL_DIR/nexafabric-agent.py --config $CONFIG_DIR/config.json
+Restart=always
+RestartSec=10
+User=root
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+if command -v systemctl >/dev/null 2>&1; then
+  systemctl daemon-reload
+  systemctl enable --now "$SERVICE_NAME.service"
+  systemctl status "$SERVICE_NAME.service" --no-pager || true
+else
+  echo "systemctl not found. Run manually: python3 $INSTALL_DIR/nexafabric-agent.py --config $CONFIG_DIR/config.json"
+fi
+"""
+
+
+@api_router.get("/nodes/{node_id}/agent/install", response_class=PlainTextResponse)
+def node_agent_install(node_id: str, request: Request, user: CurrentUser, db: Session = Depends(get_db)) -> str:
+    node = db.get(Node, node_id)
+    if not node:
+        raise HTTPException(status_code=404, detail="Node not found")
+    agent = db.get(NodeAgent, node.id)
+    if not agent:
+        agent = NodeAgent(node_id=node.id, status="pending_install", install_count=0)
+        db.add(agent)
+    agent.install_count = (agent.install_count or 0) + 1
+    token = create_token(node.id, "agent", timedelta(days=365), {"node_name": node.name})
+    write_audit(db, action="agent.install.generated", object_type="node", object_id=node.id, user_id=user.id)
+    base_url = str(request.base_url).rstrip("/")
+    return agent_install_script(base_url, token, node)
+
+
+@api_router.get("/nodes/{node_id}/agent/install-info")
+def node_agent_install_info(node_id: str, request: Request, user: CurrentUser, db: Session = Depends(get_db)) -> dict[str, str]:
+    node = db.get(Node, node_id)
+    if not node:
+        raise HTTPException(status_code=404, detail="Node not found")
+    agent = db.get(NodeAgent, node.id)
+    if not agent:
+        agent = NodeAgent(node_id=node.id, status="pending_install", install_count=0)
+        db.add(agent)
+    agent.install_count = (agent.install_count or 0) + 1
+    install_token = create_token(node.id, "agent-install", timedelta(days=7), {"node_name": node.name})
+    write_audit(db, action="agent.install.generated", object_type="node", object_id=node.id, user_id=user.id)
+    base_url = str(request.base_url).rstrip("/")
+    install_url = f"{base_url}/api/v1/agents/install/{node.id}?token={install_token}"
+    return {
+        "node_id": node.id,
+        "install_url": install_url,
+        "command": f"curl -fsSL '{install_url}' | sh",
+    }
+
+
+@api_router.get("/agents/install/{node_id}", response_class=PlainTextResponse)
+def public_node_agent_install(node_id: str, token: str, request: Request, db: Session = Depends(get_db)) -> str:
+    try:
+        claims = decode_token(token)
+    except Exception as exc:
+        raise HTTPException(status_code=401, detail="Invalid install token") from exc
+    if claims.get("typ") != "agent-install" or claims.get("sub") != node_id:
+        raise HTTPException(status_code=403, detail="Install token does not match this node")
+    node = db.get(Node, node_id)
+    if not node:
+        raise HTTPException(status_code=404, detail="Node not found")
+    agent_token = create_token(node.id, "agent", timedelta(days=365), {"node_name": node.name})
+    base_url = str(request.base_url).rstrip("/")
+    return agent_install_script(base_url, agent_token, node)
+
+
+@api_router.get("/agents/download/nexafabric-agent.py")
+def download_node_agent() -> FileResponse:
+    path = Path(__file__).resolve().parents[2] / "agent_assets" / "nexafabric-agent.py"
+    return FileResponse(path, media_type="text/x-python", filename="nexafabric-agent.py")
+
+
+@api_router.post("/agents/heartbeat")
+def agent_heartbeat(payload: AgentHeartbeat, authorization: str | None = Header(default=None), db: Session = Depends(get_db)) -> dict:
+    if not authorization or not authorization.lower().startswith("bearer "):
+        raise HTTPException(status_code=401, detail="Missing agent token")
+    token = authorization.split(" ", 1)[1]
+    try:
+        claims = decode_token(token)
+    except Exception as exc:
+        raise HTTPException(status_code=401, detail="Invalid agent token") from exc
+    if claims.get("typ") != "agent":
+        raise HTTPException(status_code=403, detail="Token is not an agent token")
+    node = db.get(Node, claims.get("sub"))
+    if not node:
+        raise HTTPException(status_code=404, detail="Node not found")
+    agent = db.get(NodeAgent, node.id)
+    if not agent:
+        agent = NodeAgent(node_id=node.id, install_count=0)
+        db.add(agent)
+    agent.status = "online"
+    agent.version = payload.version
+    agent.last_seen_at = datetime.utcnow()
+    agent.last_payload = payload.model_dump()
+    for old_flow in db.scalars(select(TrafficFlow).where(TrafficFlow.node_id == node.id)).all():
+        db.delete(old_flow)
+    for raw_flow in payload.flows[:1000]:
+        source_ip = str(raw_flow.get("source_ip") or "")
+        destination_ip = str(raw_flow.get("destination_ip") or "")
+        if not source_ip or not destination_ip:
+            continue
+        observed_at = payload.collected_at or datetime.utcnow()
+        db.add(
+            TrafficFlow(
+                node_id=node.id,
+                source_ip=source_ip,
+                destination_ip=destination_ip,
+                protocol=str(raw_flow.get("protocol") or "unknown"),
+                source_port=flow_int(raw_flow.get("source_port"), 0) or None,
+                destination_port=flow_int(raw_flow.get("destination_port"), 0) or None,
+                bytes=flow_int(raw_flow.get("bytes")),
+                packets=flow_int(raw_flow.get("packets")),
+                state=str(raw_flow.get("state") or "") or None,
+                observed_at=observed_at.replace(tzinfo=None) if observed_at.tzinfo else observed_at,
+                raw=raw_flow,
+            )
+        )
+    commit_or_400(db)
+    return {"status": "ok", "node_id": node.id}
+
+
 @api_router.get("/vms", response_model=list[WorkloadRead])
 def workloads(_: CurrentUser, db: Session = Depends(get_db)) -> list[Workload]:
     return db.scalars(select(Workload).order_by(Workload.name)).all()
@@ -632,7 +852,39 @@ def workload_insights(workload_id: str, _: CurrentUser, db: Session = Depends(ge
         select(Policy).where((Policy.project_id == workload.project_id) | (Policy.project_id.is_(None))).order_by(Policy.name)
     ).all()
     assigned_ips = db.scalars(select(IpAddress).where(IpAddress.workload_id == workload.id).order_by(IpAddress.address)).all()
+    workload_ips = [address.address for address in assigned_ips]
+    ip_owners = {
+        address.address: db.get(Workload, address.workload_id)
+        for address in db.scalars(select(IpAddress).where(IpAddress.workload_id.is_not(None))).all()
+    }
     traffic = []
+    if workload_ips:
+        flows = db.scalars(
+            select(TrafficFlow)
+            .where((TrafficFlow.source_ip.in_(workload_ips)) | (TrafficFlow.destination_ip.in_(workload_ips)))
+            .order_by(TrafficFlow.updated_at.desc())
+            .limit(50)
+        ).all()
+        for flow in flows:
+            source_owner = ip_owners.get(flow.source_ip)
+            destination_owner = ip_owners.get(flow.destination_ip)
+            traffic.append(
+                {
+                    "source": source_owner.name if source_owner else "external",
+                    "destination": destination_owner.name if destination_owner else "external",
+                    "source_ip": flow.source_ip,
+                    "destination_ip": flow.destination_ip,
+                    "protocol": flow.protocol,
+                    "port": flow.destination_port,
+                    "source_port": flow.source_port,
+                    "bytes": flow.bytes,
+                    "packets": flow.packets,
+                    "state": flow.state,
+                    "decision": "observed",
+                    "observed_at": flow.observed_at.isoformat() if flow.observed_at else None,
+                    "ip_addresses": [flow.source_ip, flow.destination_ip],
+                }
+            )
     audit_mode_notes = [
         f"{policy.name} is in audit mode; matching traffic is logged without enforcement."
         for policy in policies

backend/app/models/domain.py

@@ -2,7 +2,7 @@ from datetime import datetime
 from enum import StrEnum
 from uuid import uuid4
 
-from sqlalchemy import JSON, Boolean, DateTime, Enum, ForeignKey, Integer, String, Text, UniqueConstraint
+from sqlalchemy import JSON, BigInteger, Boolean, DateTime, Enum, ForeignKey, Integer, String, Text, UniqueConstraint
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from app.db.session import Base
@@ -129,6 +129,18 @@ class Node(Base, TimestampMixin):
     cluster: Mapped[Cluster] = relationship()
 
 
+class NodeAgent(Base, TimestampMixin):
+    __tablename__ = "node_agents"
+
+    node_id: Mapped[str] = mapped_column(ForeignKey("nodes.id"), primary_key=True)
+    status: Mapped[str] = mapped_column(String(100), default="not_installed")
+    version: Mapped[str | None] = mapped_column(String(50))
+    last_seen_at: Mapped[datetime | None] = mapped_column(DateTime)
+    last_payload: Mapped[dict | None] = mapped_column(JSON)
+    install_count: Mapped[int] = mapped_column(Integer, default=0)
+    node: Mapped[Node] = relationship()
+
+
 class Workload(Base, TimestampMixin):
     __tablename__ = "workloads"
 
@@ -183,6 +195,23 @@ class IpAddress(Base, TimestampMixin):
     note: Mapped[str | None] = mapped_column(Text)
 
 
+class TrafficFlow(Base, TimestampMixin):
+    __tablename__ = "traffic_flows"
+
+    id: Mapped[str] = mapped_column(String, primary_key=True, default=new_id)
+    node_id: Mapped[str] = mapped_column(ForeignKey("nodes.id"), index=True)
+    source_ip: Mapped[str] = mapped_column(String(100), index=True)
+    destination_ip: Mapped[str] = mapped_column(String(100), index=True)
+    protocol: Mapped[str] = mapped_column(String(20), default="unknown")
+    source_port: Mapped[int | None] = mapped_column(Integer)
+    destination_port: Mapped[int | None] = mapped_column(Integer)
+    bytes: Mapped[int] = mapped_column(BigInteger, default=0)
+    packets: Mapped[int] = mapped_column(BigInteger, default=0)
+    state: Mapped[str | None] = mapped_column(String(100))
+    observed_at: Mapped[datetime | None] = mapped_column(DateTime)
+    raw: Mapped[dict | None] = mapped_column(JSON)
+
+
 class SecurityGroup(Base, TimestampMixin):
     __tablename__ = "security_groups"
 

backend/app/schemas/domain.py

@@ -181,6 +181,34 @@ class NodeRead(OrmModel):
     memory_mb: int
 
 
+class NodeAgentRead(BaseModel):
+    node_id: str
+    status: str
+    version: str | None = None
+    last_seen_at: datetime | None = None
+    install_count: int = 0
+    last_payload: dict[str, Any] | None = None
+
+
+class NodeWithAgentRead(NodeRead):
+    agent: NodeAgentRead | None = None
+
+
+class AgentHeartbeat(BaseModel):
+    version: str
+    node_name: str | None = None
+    collected_at: datetime | None = None
+    hostname: str | None = None
+    kernel: str | None = None
+    uptime_seconds: float | None = None
+    loadavg: list[float] = []
+    interfaces: list[dict[str, Any]] = []
+    flows: list[dict[str, Any]] = []
+    conntrack: dict[str, Any] = {}
+    firewall: dict[str, Any] = {}
+    extra: dict[str, Any] = {}
+
+
 class WorkloadRead(OrmModel):
     id: str
     cluster_id: str

frontend/src/App.tsx

@@ -11,6 +11,7 @@ import { Ipam } from "./pages/Ipam";
 import { ListPage } from "./pages/ListPage";
 import { Login } from "./pages/Login";
 import { Networks } from "./pages/Networks";
+import { Nodes } from "./pages/Nodes";
 import { Policies } from "./pages/Policies";
 import { PolicyDesigner } from "./pages/PolicyDesigner";
 import { SecurityGroups } from "./pages/SecurityGroups";
@@ -46,7 +47,7 @@ function AppRoutes() {
       <Route element={<Layout />}>
         <Route index element={<Dashboard />} />
         <Route path="clusters" element={<Clusters />} />
-        <Route path="nodes" element={<ListPage title="Nodes" subtitle="Cluster nodes, capacity, and health." path="/nodes" columns={[{ key: "name", label: "Name" }, { key: "status", label: "Status" }, { key: "cpu_count", label: "CPU" }, { key: "memory_mb", label: "Memory MB" }]} />} />
+        <Route path="nodes" element={<Nodes />} />
         <Route path="workloads" element={<Workloads />} />
         <Route path="networks" element={<Networks />} />
         <Route path="ipam" element={<Ipam />} />

frontend/src/api/client.ts

@@ -126,6 +126,31 @@ export type Workload = {
   tags: string[];
 };
 
+export type NodeAgent = {
+  node_id: string;
+  status: string;
+  version: string | null;
+  last_seen_at: string | null;
+  install_count: number;
+  last_payload: Record<string, unknown> | null;
+};
+
+export type Node = {
+  id: string;
+  cluster_id: string;
+  name: string;
+  status: string;
+  cpu_count: number;
+  memory_mb: number;
+  agent: NodeAgent | null;
+};
+
+export type AgentInstallInfo = {
+  node_id: string;
+  install_url: string;
+  command: string;
+};
+
 export type WorkloadInsight = {
   workload: Workload;
   assigned_ips: IpAddress[];

frontend/src/pages/Nodes.tsx

@@ -0,0 +1,98 @@
+import { useMutation, useQuery } from "@tanstack/react-query";
+import { Cpu, Copy, RadioTower } from "lucide-react";
+import { useState } from "react";
+
+import { AgentInstallInfo, api, Node } from "../api/client";
+import { DataTable } from "../components/DataTable";
+import { iconButtonClass, secondaryButtonClass } from "../components/FormControls";
+import { Modal } from "../components/Modal";
+import { PageHeader } from "../components/PageHeader";
+
+export function Nodes() {
+  const nodes = useQuery({ queryKey: ["nodes-agents"], queryFn: () => api<Node[]>("/nodes/agents") });
+  const [selectedNode, setSelectedNode] = useState<Node | null>(null);
+  const [copied, setCopied] = useState(false);
+  const installInfo = useMutation({
+    mutationFn: (node: Node) => api<AgentInstallInfo>(`/nodes/${node.id}/agent/install-info`),
+    onSuccess: (_data, node) => {
+      setSelectedNode(node);
+      setCopied(false);
+    },
+  });
+
+  async function copyCommand() {
+    if (!installInfo.data) {
+      return;
+    }
+    await navigator.clipboard.writeText(installInfo.data.command);
+    setCopied(true);
+  }
+
+  return (
+    <>
+      <PageHeader title="Nodes" subtitle="Cluster nodes, capacity, health, and NexaFabric agent enrollment." />
+      {nodes.isLoading ? <div className="rounded-md border border-border bg-panel p-8 text-sm">Loading...</div> : null}
+      {nodes.error ? <div className="rounded-md border border-danger p-4 text-sm text-danger">Failed to load nodes.</div> : null}
+      {!nodes.isLoading && !nodes.error ? (
+        <DataTable
+          rows={(nodes.data ?? []) as unknown as Record<string, unknown>[]}
+          columns={[
+            { key: "name", label: "Name" },
+            { key: "status", label: "Status" },
+            { key: "cpu_count", label: "CPU" },
+            { key: "memory_mb", label: "Memory MB" },
+            {
+              key: "agent",
+              label: "Agent",
+              render: (row) => {
+                const node = row as unknown as Node;
+                return node.agent ? `${node.agent.status}${node.agent.version ? ` · ${node.agent.version}` : ""}` : "not_installed";
+              },
+            },
+            {
+              key: "actions",
+              label: "Actions",
+              render: (row) => {
+                const node = row as unknown as Node;
+                return (
+                  <div className="flex justify-end gap-2">
+                    <button
+                      className={iconButtonClass}
+                      title="Install node agent"
+                      aria-label={`Install agent on ${node.name}`}
+                      onClick={() => installInfo.mutate(node)}
+                    >
+                      <RadioTower size={16} />
+                    </button>
+                  </div>
+                );
+              },
+            },
+          ]}
+        />
+      ) : null}
+      <Modal title="Install Node Agent" open={Boolean(selectedNode)} onClose={() => setSelectedNode(null)}>
+        <div className="space-y-4">
+          <div className="flex items-center gap-2 font-medium">
+            <Cpu size={18} />
+            {selectedNode?.name}
+          </div>
+          <div className="rounded-md border border-border bg-canvas p-3 text-xs text-slate-500 dark:text-slate-400">
+            Run this command as root on the Proxmox node. It installs the agent under <code>/opt/nexafabric-agent</code> and starts a systemd service.
+          </div>
+          <pre className="max-h-48 overflow-auto rounded-md border border-border bg-canvas p-3 text-xs">
+            {installInfo.data?.command ?? "Generating installer..."}
+          </pre>
+          <div className="grid gap-2 text-xs">
+            <span className="text-slate-500 dark:text-slate-400">Installer link</span>
+            <code className="break-all rounded-md border border-border bg-canvas p-3">{installInfo.data?.install_url ?? ""}</code>
+          </div>
+          <button className={secondaryButtonClass} disabled={!installInfo.data} onClick={copyCommand}>
+            <Copy size={16} />
+            {copied ? "Copied" : "Copy Command"}
+          </button>
+        </div>
+      </Modal>
+    </>
+  );
+}