Merge pull request #1847 from balena-os/apps-json-rename

Rename apps.json after initial preload

src/device-state/preload.ts

@@ -8,21 +8,19 @@ import * as deviceConfig from '../device-config';
 import * as eventTracker from '../event-tracker';
 import * as images from '../compose/images';
 
-import constants = require('../lib/constants');
 import { AppsJsonParseError, EISDIR, ENOENT } from '../lib/errors';
 import log from '../lib/supervisor-console';
 
 import { convertLegacyAppsJson } from '../lib/migration';
 import { AppsJsonFormat } from '../types/state';
+import * as fsUtils from '../lib/fs-utils';
 
-export async function loadTargetFromFile(
+export function appsJsonBackup(appsPath: string) {
-	appsPath: Nullable<string>,
+	return `${appsPath}.preloaded`;
-): Promise<void> {
+}
+
+export async function loadTargetFromFile(appsPath: string): Promise<void> {
 	log.info('Attempting to load any preloaded applications');
-	if (!appsPath) {
-		appsPath = constants.appsJsonPath;
-	}
-
 	try {
 		const content = await fs.readFile(appsPath, 'utf8');
 
@@ -73,7 +71,7 @@ export async function loadTargetFromFile(
 		}
 
 		for (const image of imgs) {
-			const name = await images.normalise(image.name);
+			const name = images.normalise(image.name);
 			image.name = name;
 			await images.save(image);
 		}
@@ -114,5 +112,23 @@ export async function loadTargetFromFile(
 				error: e,
 			});
 		}
+	} finally {
+		const targetPath = appsJsonBackup(appsPath);
+		if (!(await fsUtils.exists(targetPath))) {
+			// Try to rename the path so the preload target state won't
+			// be used again if the database gets deleted for any reason.
+			// If the target file already exists or something fails, just debug
+			// the failure.
+			await fsUtils
+				.safeRename(appsPath, targetPath)
+				.then(() => fsUtils.writeFileAtomic(appsPath, '{}'))
+				.then(() => log.debug(`Migrated existing apps.json`))
+				.catch((e) =>
+					log.debug(
+						`Continuing without migrating apps.json because of`,
+						e.message,
+					),
+				);
+		}
 	}
 }

src/lib/constants.ts

@@ -1,3 +1,4 @@
+import * as path from 'path';
 import { checkString } from './validation';
 
 const bootMountPointFromEnv = checkString(process.env.BOOT_MOUNTPOINT);
@@ -49,7 +50,9 @@ const constants = {
 		'lo',
 		supervisorNetworkInterface,
 	],
-	appsJsonPath: process.env.APPS_JSON_PATH || '/boot/apps.json',
+	appsJsonPath:
+		process.env.APPS_JSON_PATH ||
+		path.join(rootMountPoint, '/mnt/data', 'apps.json'),
 	ipAddressUpdateInterval: 30 * 1000,
 	imageCleanupErrorIgnoreTimeout: 3600 * 1000,
 	maxDeltaDownloads: 3,

test/05-device-state.spec.ts

@@ -10,10 +10,14 @@ import * as images from '../src/compose/images';
 import { ConfigTxt } from '../src/config/backends/config-txt';
 import * as deviceState from '../src/device-state';
 import * as deviceConfig from '../src/device-config';
-import { loadTargetFromFile } from '../src/device-state/preload';
+import {
+	loadTargetFromFile,
+	appsJsonBackup,
+} from '../src/device-state/preload';
 import Service from '../src/compose/service';
 import { intialiseContractRequirements } from '../src/lib/contracts';
 import * as updateLock from '../src/lib/update-lock';
+import * as fsUtils from '../src/lib/fs-utils';
 
 const mockedInitialConfig = {
 	RESIN_SUPERVISOR_CONNECTIVITY_CHECK: 'true',
@@ -224,8 +228,10 @@ describe('deviceState', () => {
 	});
 
 	it('loads a target state from an apps.json file and saves it as target state, then returns it', async () => {
-		await loadTargetFromFile(process.env.ROOT_MOUNTPOINT + '/apps.json');
+		const appsJson = process.env.ROOT_MOUNTPOINT + '/apps.json';
+		await loadTargetFromFile(appsJson);
 		const targetState = await deviceState.getTarget();
+		expect(await fsUtils.exists(appsJsonBackup(appsJson))).to.be.true;
 
 		expect(targetState)
 			.to.have.property('local')
@@ -283,14 +289,22 @@ describe('deviceState', () => {
 			.to.have.property('labels')
 			.that.has.property('io.balena.something')
 			.that.equals('bar');
+
+		// Restore renamed apps.json
+		await fsUtils.safeRename(appsJsonBackup(appsJson), appsJson);
 	});
 
 	it('stores info for pinning a device after loading an apps.json with a pinDevice field', async () => {
-		await loadTargetFromFile(process.env.ROOT_MOUNTPOINT + '/apps-pin.json');
+		const appsJson = process.env.ROOT_MOUNTPOINT + '/apps-pin.json';
+		await loadTargetFromFile(appsJson);
 
 		const pinned = await config.get('pinDevice');
 		expect(pinned).to.have.property('app').that.equals(1234);
 		expect(pinned).to.have.property('commit').that.equals('abcdef');
+		expect(await fsUtils.exists(appsJsonBackup(appsJson))).to.be.true;
+
+		// Restore renamed apps.json
+		await fsUtils.safeRename(appsJsonBackup(appsJson), appsJson);
 	});
 
 	it('emits a change event when a new state is reported', (done) => {
@@ -303,7 +317,7 @@ describe('deviceState', () => {
 
 		const services: Service[] = [];
 		for (const service of testTarget.local.apps['1234'].services) {
-			const imageName = await images.normalise(service.image);
+			const imageName = images.normalise(service.image);
 			service.image = imageName;
 			(service as any).imageName = imageName;
 			services.push(