Updates

server/services/collectors/ebpf-bridge.js

@@ -0,0 +1,129 @@
+/**
+ * eBPF metrics bridge — ingests samples from an external helper.
+ *
+ * The agent cannot load eBPF programs in pure JS. Instead, a privileged helper
+ * can write JSON lines to a file or unix socket path:
+ *
+ *   PEARDATA_EBPF=1
+ *   PEARDATA_EBPF_PATH=/run/peardata/ebpf.ndjson
+ *
+ * Each line: {"chart":"ebpf.cachestat","values":{"hits":1,"misses":2},"ts":...}
+ *
+ * Charts are registered dynamically under context ebpf.*.
+ */
+import fs from 'fs'
+import { EventEmitter } from 'events'
+import { SAMPLE_INTERVAL_MS, registerChart } from '../../../shared/metrics.js'
+import logger from '../../utils/logger.js'
+
+const log = logger.child('ebpf-bridge')
+
+export function isEbpfBridgeEnabled() {
+  const v = process.env.PEARDATA_EBPF
+  return v === '1' || v === 'on' || v === 'true'
+}
+
+function bridgePath() {
+  return process.env.PEARDATA_EBPF_PATH || '/run/peardata/ebpf.ndjson'
+}
+
+export class EbpfBridgeCollector extends EventEmitter {
+  constructor(opts = {}) {
+    super()
+    this.intervalMs =
+      opts.intervalMs ?? (Number(process.env.PEARDATA_SAMPLE_MS) || SAMPLE_INTERVAL_MS)
+    this.timer = null
+    this.running = false
+    this.offset = 0
+  }
+
+  start() {
+    if (this.running) return
+    this.running = true
+    this._tick()
+    this.timer = setInterval(() => this._tick(), this.intervalMs)
+    if (this.timer.unref) this.timer.unref()
+    log.info('eBPF bridge started', { path: bridgePath() })
+  }
+
+  stop() {
+    this.running = false
+    if (this.timer) clearInterval(this.timer)
+    this.timer = null
+  }
+
+  _tick() {
+    const p = bridgePath()
+    let st
+    try {
+      st = fs.statSync(p)
+    } catch {
+      return
+    }
+    if (st.size < this.offset) this.offset = 0
+    if (st.size === this.offset) return
+    let fd
+    try {
+      fd = fs.openSync(p, 'r')
+      const len = st.size - this.offset
+      const buf = Buffer.alloc(Math.min(len, 256 * 1024))
+      const n = fs.readSync(fd, buf, 0, buf.length, this.offset)
+      this.offset += n
+      const text = buf.slice(0, n).toString('utf8')
+      const ts = Date.now()
+      /** @type {Array<{ chart: string, context: string, ts: number, values: object }>} */
+      const batch = []
+      for (const line of text.split('\n')) {
+        if (!line.trim()) continue
+        let row
+        try {
+          row = JSON.parse(line)
+        } catch {
+          continue
+        }
+        if (!row?.chart || !row.values) continue
+        const chart = String(row.chart).startsWith('ebpf.')
+          ? String(row.chart)
+          : `ebpf.${String(row.chart)}`
+        const dims = Object.keys(row.values).map((id) => ({
+          id,
+          name: id,
+          algorithm: 'absolute',
+        }))
+        registerChart({
+          id: chart,
+          name: chart,
+          context: chart.split('.').slice(0, 2).join('.') || 'ebpf.metric',
+          title: chart,
+          units: row.units || 'events',
+          family: 'ebpf',
+          chartType: 'line',
+          priority: 9500,
+          plugin: 'ebpf-bridge',
+          dimensions: dims,
+        })
+        batch.push({
+          chart,
+          context: chart,
+          ts: row.ts || ts,
+          values: row.values,
+        })
+      }
+      if (batch.length) this.emit('samples', batch)
+    } catch (err) {
+      log.warn('eBPF bridge read failed', { error: err.message })
+    } finally {
+      try {
+        if (fd != null) fs.closeSync(fd)
+      } catch {
+        // ignore
+      }
+    }
+  }
+}
+
+let singleton = null
+export function getEbpfBridgeCollector() {
+  if (!singleton) singleton = new EbpfBridgeCollector()
+  return singleton
+}