From 1520e10a59cb194d22427510edd528d03690baac Mon Sep 17 00:00:00 2001
From: cupcakearmy <hi@nicco.io>
Date: Sun, 17 May 2020 18:13:50 +0200
Subject: [PATCH] do not allow multiple instances

---
 src/autorestic.ts | 16 ++++++++++++++--
 src/cron.ts       | 40 ++++++----------------------------------
 src/lock.ts       | 32 ++++++++++++++++++++++++++++++++
 src/types.ts      |  7 +++++--
 4 files changed, 57 insertions(+), 38 deletions(-)
 create mode 100644 src/lock.ts

diff --git a/src/autorestic.ts b/src/autorestic.ts
index 0289701..d584431 100644
--- a/src/autorestic.ts
+++ b/src/autorestic.ts
@@ -4,11 +4,11 @@ import minimist from 'minimist'
 import { init } from './config'
 import handlers, { error, help } from './handlers'
 import { Config } from './types'
-
-
+import { readLock, writeLock, unlock } from './lock'
 
 process.on('uncaughtException', err => {
 	console.log(err.message)
+	unlock()
 	process.exit(1)
 })
 
@@ -36,6 +36,17 @@ export let config: Config
 async function main() {
 	config = init()
 
+	// Don't let 2 instances run on the same config
+	const lock = readLock()
+	if (lock.running) {
+		console.log('An instance of autorestic is already running for this config file'.red)
+		return
+	}
+	writeLock({
+		...lock,
+		running: true,
+	})
+
 	// For dev
 	// return await handlers['cron']([], { ...flags, all: true })
 
@@ -46,6 +57,7 @@ async function main() {
 
 	const fn = handlers[command] || error
 	await fn(args, flags)
+	unlock()
 }
 
 
diff --git a/src/cron.ts b/src/cron.ts
index b70704f..087d23a 100644
--- a/src/cron.ts
+++ b/src/cron.ts
@@ -1,49 +1,21 @@
-import fs from 'fs'
-
 import CronParser from 'cron-parser'
 
 import { config } from './autorestic'
 import { checkAndConfigureBackendsForLocations } from './backend'
-import { Location, Lockfile } from './types'
+import { Location } from './types'
 import { backupLocation } from './backup'
-import { pathRelativeToConfigFile } from './utils'
+import { readLock, writeLock } from './lock'
 
 
-const getLockFileName = () => {
-  const LOCK_FILE = '.autorestic.lock'
-  return pathRelativeToConfigFile(LOCK_FILE)
-}
-
-const readLock = (): Lockfile => {
-  const name = getLockFileName()
-  let lock = {}
-  try {
-    lock = JSON.parse(fs.readFileSync(name, { encoding: 'utf-8' }))
-  } catch { }
-  return lock
-}
-const writeLock = (diff: Lockfile = {}) => {
-  const name = getLockFileName()
-  const newLock = Object.assign(
-    readLock(),
-    diff
-  )
-  fs.writeFileSync(name, JSON.stringify(newLock, null, 2), { encoding: 'utf-8' })
-}
-
 const runCronForLocation = (name: string, location: Location) => {
-  const lock = readLock()[name]
+  const lock = readLock()
   const parsed = CronParser.parseExpression(location.cron || '')
   const last = parsed.prev()
 
-  if (!lock || last.toDate().getTime() > lock.lastRun) {
+  if (!lock.crons[name] || last.toDate().getTime() > lock.crons[name].lastRun) {
     backupLocation(name, location)
-    writeLock({
-      [name]: {
-        ...lock,
-        lastRun: Date.now()
-      }
-    })
+    lock.crons[name] = { lastRun: Date.now() }
+    writeLock(lock)
   } else {
     console.log(`${name.yellow} ▶ Skipping. Sheduled for: ${parsed.next().toString().underline.blue}`)
   }
diff --git a/src/lock.ts b/src/lock.ts
new file mode 100644
index 0000000..962d463
--- /dev/null
+++ b/src/lock.ts
@@ -0,0 +1,32 @@
+import fs from 'fs'
+
+import { pathRelativeToConfigFile } from "./utils"
+import { Lockfile } from "./types"
+
+export const getLockFileName = () => {
+  const LOCK_FILE = '.autorestic.lock'
+  return pathRelativeToConfigFile(LOCK_FILE)
+}
+
+export const readLock = (): Lockfile => {
+  const name = getLockFileName()
+  let lock = {
+    running: false,
+    crons: {}
+  }
+  try {
+    lock = JSON.parse(fs.readFileSync(name, { encoding: 'utf-8' }))
+  } catch { }
+  return lock
+}
+export const writeLock = (lock: Lockfile) => {
+  const name = getLockFileName()
+  fs.writeFileSync(name, JSON.stringify(lock, null, 2), { encoding: 'utf-8' })
+}
+
+export const unlock = () => {
+  writeLock({
+    ...readLock(),
+    running: false,
+  })
+}
\ No newline at end of file
diff --git a/src/types.ts b/src/types.ts
index 5cad816..1380d22 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -93,8 +93,11 @@ export type Config = {
 }
 
 export type Lockfile = {
-	[name: string]: {
-		lastRun: number
+	running: boolean
+	crons: {
+		[name: string]: {
+			lastRun: number
+		}
 	}
 }