# services/monitoring/jetson-tegrastats-exporter.yaml
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: jetson-tegrastats-exporter
  namespace: monitoring
  labels:
    app: jetson-tegrastats-exporter
spec:
  selector:
    matchLabels:
      app: jetson-tegrastats-exporter
  template:
    metadata:
      labels:
        app: jetson-tegrastats-exporter
      annotations:
        prometheus.io/scrape: "true"
        prometheus.io/port: "9100"
    spec:
      serviceAccountName: default
      hostPID: true
      tolerations:
        - operator: Exists
      nodeSelector:
        jetson: "true"
      containers:
        - name: exporter
          # Exposes tegrastats output as Prometheus metrics for Jetson devices.
          image: python:3.10-slim
          imagePullPolicy: IfNotPresent
          securityContext:
            privileged: true
          ports:
            - name: metrics
              containerPort: 9100
          resources:
            requests:
              cpu: 50m
              memory: 64Mi
            limits:
              cpu: 200m
              memory: 256Mi
          env:
            - name: JETSON_EXPORTER_PORT
              value: "9100"
          volumeMounts:
            - name: script
              mountPath: /etc/tegrastats-exporter
              readOnly: true
            - name: tegrastats-bin
              mountPath: /host/usr/bin/tegrastats
              readOnly: true
          command:
            - python
            - /etc/tegrastats-exporter/exporter.py
      volumes:
        - name: script
          configMap:
            name: jetson-tegrastats-exporter-script
            defaultMode: 0555
        - name: tegrastats-bin
          hostPath:
            path: /usr/bin/tegrastats
            type: File
---
apiVersion: v1
kind: Service
metadata:
  name: jetson-tegrastats-exporter
  namespace: monitoring
  labels:
    app: jetson-tegrastats-exporter
spec:
  selector:
    app: jetson-tegrastats-exporter
  ports:
    - name: metrics
      port: 9100
      targetPort: metrics
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: jetson-tegrastats-exporter-script
  namespace: monitoring
data:
  exporter.py: |
    import http.server
    import os
    import re
    import socketserver
    import subprocess
    import threading
    from time import time

    PORT = int(os.environ.get("JETSON_EXPORTER_PORT", "9100"))
    METRICS = {
        "gr3d_freq_percent": 0.0,
        "gpu_temp_c": 0.0,
        "cpu_temp_c": 0.0,
        "ram_used_mb": 0.0,
        "ram_total_mb": 0.0,
        "power_5v_in_mw": 0.0,
        "last_scrape_ts": 0.0,
    }
    LOCK = threading.Lock()

    def parse_line(line: str):
        updates = {}
        m = re.search(r"GR3D_FREQ\\s+(\\d+)%", line)
        if m:
            updates["gr3d_freq_percent"] = float(m.group(1))
        m = re.search(r"GPU@(\\d+(?:\\.\\d+)?)C", line)
        if m:
            updates["gpu_temp_c"] = float(m.group(1))
        m = re.search(r"CPU@(\\d+(?:\\.\\d+)?)C", line)
        if m:
            updates["cpu_temp_c"] = float(m.group(1))
        m = re.search(r"RAM\\s+(\\d+)/(\\d+)MB", line)
        if m:
            updates["ram_used_mb"] = float(m.group(1))
            updates["ram_total_mb"] = float(m.group(2))
        m = re.search(r"POM_5V_IN\\s+(\\d+)/(\\d+)", line)
        if m:
            updates["power_5v_in_mw"] = float(m.group(1))
        with LOCK:
            METRICS.update(updates)
            METRICS["last_scrape_ts"] = time()

    def run_tegrastats():
        proc = subprocess.Popen(
            ["/host/usr/bin/tegrastats", "--interval", "1000"],
            stdout=subprocess.PIPE,
            stderr=subprocess.STDOUT,
            text=True,
            bufsize=1,
        )
        for line in proc.stdout:
            parse_line(line)

    class Handler(http.server.BaseHTTPRequestHandler):
        def do_GET(self):
            if self.path != "/metrics":
                self.send_response(404)
                self.end_headers()
                return
            with LOCK:
                metrics = METRICS.copy()
            out = []
            for k, v in metrics.items():
                out.append(f"# TYPE jetson_{k} gauge")
                out.append(f"jetson_{k} {v}")
            body = "\\n".join(out) + "\\n"
            self.send_response(200)
            self.send_header("Content-Type", "text/plain; version=0.0.4")
            self.send_header("Content-Length", str(len(body)))
            self.end_headers()
            self.wfile.write(body.encode("utf-8"))

        def log_message(self, fmt, *args):
            return

    if __name__ == "__main__":
        t = threading.Thread(target=run_tegrastats, daemon=True)
        t.start()
        with socketserver.TCPServer(("", PORT), Handler) as httpd:
            httpd.serve_forever()