From cc1427882f4278eac86d26317c4be1341e4c75fe Mon Sep 17 00:00:00 2001
From: Aarnav Tale <aarnavtale@icloud.com>
Date: Sat, 30 Mar 2024 02:53:51 -0400
Subject: [PATCH] feat: watch config file for external edits

---
 app/root.tsx        |  3 ++-
 app/utils/config.ts | 20 +++++++++++++++++---
 package.json        |  1 +
 pnpm-lock.yaml      |  3 +++
 4 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/app/root.tsx b/app/root.tsx
index 9f5a19c..bcc3497 100644
--- a/app/root.tsx
+++ b/app/root.tsx
@@ -10,7 +10,7 @@ import {
 import { ErrorPopup } from '~/components/Error'
 import Toaster from '~/components/Toaster'
 import stylesheet from '~/tailwind.css?url'
-import { getContext } from '~/utils/config'
+import { getContext, registerConfigWatcher } from '~/utils/config'
 
 export const meta: MetaFunction = () => [
 	{ title: 'Headplane' },
@@ -23,6 +23,7 @@ export const links: LinksFunction = () => [
 
 export async function loader() {
 	await getContext()
+	registerConfigWatcher()
 
 	if (!process.env.HEADSCALE_URL) {
 		throw new Error('The HEADSCALE_URL environment variable is required')
diff --git a/app/utils/config.ts b/app/utils/config.ts
index 6948c2f..eb57271 100644
--- a/app/utils/config.ts
+++ b/app/utils/config.ts
@@ -1,6 +1,7 @@
-import { access, constants, readFile, stat, writeFile } from 'node:fs/promises'
+import { access, constants, readFile, writeFile } from 'node:fs/promises'
 import { resolve } from 'node:path'
 
+import { type FSWatcher, watch } from 'chokidar'
 import { type Document, parseDocument } from 'yaml'
 
 type Duration = `${string}s` | `${string}h` | `${string}m` | `${string}d` | `${string}y`
@@ -120,8 +121,8 @@ type Config = {
 
 let config: Document
 
-export async function getConfig() {
-	if (!config) {
+export async function getConfig(force = false) {
+	if (!config || force) {
 		const path = resolve(process.env.CONFIG_FILE ?? '/etc/headscale/config.yaml')
 		const data = await readFile(path, 'utf8')
 		config = parseDocument(data)
@@ -140,6 +141,19 @@ export async function patchConfig(partial: Record<string, unknown>) {
 	await writeFile(path, config.toString(), 'utf8')
 }
 
+let watcher: FSWatcher
+
+export function registerConfigWatcher() {
+	if (watcher) {
+		return
+	}
+
+	const path = resolve(process.env.CONFIG_FILE ?? '/etc/headscale/config.yaml')
+	watcher = watch(path).on('change', async () => {
+		await getConfig(true)
+	})
+}
+
 type Context = {
 	hasDockerSock: boolean;
 	hasConfig: boolean;
diff --git a/package.json b/package.json
index f2b5eb0..5a881ab 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,7 @@
 		"@remix-run/node": "^2.8.1",
 		"@remix-run/react": "^2.8.1",
 		"@remix-run/serve": "^2.8.1",
+		"chokidar": "^3.6.0",
 		"clsx": "^2.1.0",
 		"isbot": "^4.1.0",
 		"oauth4webapi": "^2.10.3",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index b744b87..623c5d7 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -32,6 +32,9 @@ dependencies:
   '@remix-run/serve':
     specifier: ^2.8.1
     version: 2.8.1(typescript@5.4.3)
+  chokidar:
+    specifier: ^3.6.0
+    version: 3.6.0
   clsx:
     specifier: ^2.1.0
     version: 2.1.0