feat: configure support for generic integrations

Co-authored-by: Gage Orsburn <gageorsburn@live.com>

app/integration/proc.ts

@@ -0,0 +1,80 @@
+import { access, constants, readdir, readFile } from 'node:fs/promises'
+import { platform } from 'node:os'
+import { join, resolve } from 'node:path'
+import { kill } from 'node:process'
+
+import type { Integration } from '.'
+
+// Check if we have a /proc and if it's readable
+async function preflight() {
+	if (platform() !== 'linux') {
+		return false
+	}
+
+	const dir = resolve('/proc')
+	try {
+		await access(dir, constants.R_OK)
+		return true
+	} catch (error) {
+		console.error('Failed to access /proc', error)
+		return false
+	}
+}
+
+async function findPid() {
+	const dirs = await readdir('/proc')
+
+	const promises = dirs.map(async (dir) => {
+		const pid = Number.parseInt(dir, 10)
+
+		if (Number.isNaN(pid)) {
+			return
+		}
+
+		const path = join('/proc', dir, 'cmdline')
+		try {
+			const data = await readFile(path, 'utf8')
+			if (data.includes('headscale')) {
+				return pid
+			}
+		} catch {}
+	})
+
+	const results = await Promise.allSettled(promises)
+	const pids = []
+
+	for (const result of results) {
+		if (result.status === 'fulfilled') {
+			pids.push(result.value)
+		}
+	}
+
+	if (pids.length > 1) {
+		console.warn('Found multiple Headscale processes', pids)
+		console.log('Disabling the /proc integration')
+		return
+	}
+
+	if (pids.length === 0) {
+		console.warn('Could not find Headscale process')
+		console.log('Disabling the /proc integration')
+		return
+	}
+
+	return pids[0]
+}
+
+async function sighup() {
+	const pid = await findPid()
+	if (!pid) {
+		return
+	}
+
+	try {
+		kill(pid, 'SIGHUP')
+	} catch (error) {
+		console.error('Failed to send SIGHUP to Headscale', error)
+	}
+}
+
+export default { preflight, sighup } satisfies Integration