Embed balena-image-manager instead of having it as a dependency

Change-type: patch

src/commands/os/download.ts

@@ -89,7 +89,7 @@ export default class OsDownloadCmd extends Command {
 
 		// balenaOS ESR versions require user authentication
 		if (options.version) {
-			const { isESR } = await import('balena-image-manager');
+			const { isESR } = await import('../../utils/image-manager');
 			if (options.version === 'menu-esr' || isESR(options.version)) {
 				try {
 					await OsDownloadCmd.checkLoggedIn();

src/utils/cloud.ts

@@ -145,8 +145,8 @@ export async function downloadOSImage(
 	// some ongoing issues with the os download stream.
 	process.env.ZLIB_FLUSH = 'Z_NO_FLUSH';
 
-	const manager = await import('balena-image-manager');
-	const stream = await manager.get(deviceType, OSVersion);
+	const { getStream } = await import('./image-manager');
+	const stream = await getStream(deviceType, OSVersion);
 
 	const displayVersion = await new Promise((resolve, reject) => {
 		stream.on('error', reject);

src/utils/image-manager.ts

@@ -0,0 +1,311 @@
+/**
+ * @license
+ * Copyright 2019 Balena Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import type * as SDK from 'balena-sdk';
+import { getBalenaSdk } from './lazy';
+
+// eslint-disable-next-line no-useless-escape
+const BALENAOS_VERSION_REGEX = /v?\d+\.\d+\.\d+(\.rev\d+)?((\-|\+).+)?/;
+
+/**
+ * @summary Check if the string is a valid balenaOS version number
+ * @function
+ * @protected
+ * @description Throws an error if the version is invalid
+ *
+ * @param {String} version - version number to validate
+ * @returns {void} the most recent compatible version.
+ */
+const validateVersion = (version: string) => {
+	if (!BALENAOS_VERSION_REGEX.test(version)) {
+		throw new Error('Invalid version number');
+	}
+};
+
+/**
+ * @summary Get file created date
+ * @function
+ * @protected
+ *
+ * @param {String} filePath - file path
+ * @returns {Promise<Date>} date since creation
+ *
+ * @example
+ * utils.getFileCreatedDate('foo/bar').then (createdTime) ->
+ * 	console.log("The file was created in #{createdTime}")
+ */
+const getFileCreatedDate = async (filePath: string) => {
+	const { promises: fs } = await import('fs');
+	const { ctime } = await fs.stat(filePath);
+	return ctime;
+};
+
+/**
+ * @summary Get path to image in cache
+ * @function
+ * @protected
+ *
+ * @param {String} deviceType - device type slug or alias
+ * @param {String} version - the exact balenaOS version number
+ * @returns {Promise<String>} image path
+ *
+ * @example
+ * cache.getImagePath('raspberry-pi', '1.2.3').then (imagePath) ->
+ * 	console.log(imagePath)
+ */
+const getImagePath = async (deviceType: string, version?: string) => {
+	if (typeof version === 'string') {
+		validateVersion(version);
+	}
+	const balena = getBalenaSdk();
+	const [cacheDirectory, deviceTypeInfo] = await Promise.all([
+		balena.settings.get('cacheDirectory'),
+		balena.models.config.getDeviceTypeManifestBySlug(deviceType),
+	]);
+	const extension = deviceTypeInfo.yocto.fstype === 'zip' ? 'zip' : 'img';
+	const path = await import('path');
+	return path.join(cacheDirectory, `${deviceType}-v${version}.${extension}`);
+};
+
+/**
+ * @summary Determine if a device image is fresh
+ * @function
+ * @protected
+ *
+ * @description
+ * If the device image does not exist, return false.
+ *
+ * @param {String} deviceType - device type slug or alias
+ * @param {String} version - the exact balenaOS version number
+ * @returns {Promise<Boolean>} is image fresh
+ *
+ * @example
+ * utils.isImageFresh('raspberry-pi', '1.2.3').then (isFresh) ->
+ * 	if isFresh
+ * 		console.log('The Raspberry Pi image v1.2.3 is fresh!')
+ */
+const isImageFresh = async (deviceType: string, version: string) => {
+	const imagePath = await getImagePath(deviceType, version);
+	let createdDate;
+	try {
+		createdDate = await getFileCreatedDate(imagePath);
+	} catch {
+		// Swallow errors from utils.getFileCreatedTime.
+	}
+	if (createdDate == null) {
+		return false;
+	}
+
+	const balena = getBalenaSdk();
+	const lastModifiedDate = await balena.models.os.getLastModified(
+		deviceType,
+		version,
+	);
+	return lastModifiedDate < createdDate;
+};
+
+/**
+ * Heuristically determine whether the given semver version is a balenaOS
+ * ESR version.
+ *
+ * @param {string} version Semver version. If invalid or range, return false.
+ */
+export const isESR = (version: string) => {
+	const match = version.match(/^v?(\d+)\.\d+\.\d+/);
+	const major = parseInt((match && match[1]) || '', 10);
+	return major >= 2018; // note: (NaN >= 2018) is false
+};
+
+/**
+ * @summary Get the most recent compatible version
+ * @function
+ * @protected
+ *
+ * @param {String} deviceType - device type slug or alias
+ * @param {String} versionOrRange - supports the same version options
+ * as `balena.models.os.getMaxSatisfyingVersion`.
+ * See `manager.get` for the detailed explanation.
+ * @returns {Promise<String>} the most recent compatible version.
+ */
+const resolveVersion = async (deviceType: string, versionOrRange: string) => {
+	const balena = getBalenaSdk();
+	const version = await balena.models.os.getMaxSatisfyingVersion(
+		deviceType,
+		versionOrRange,
+		isESR(versionOrRange) ? 'esr' : 'default',
+	);
+	if (!version) {
+		throw new Error('No such version for the device type');
+	}
+	return version;
+};
+
+/**
+ * @summary Get an image from the cache
+ * @function
+ * @protected
+ *
+ * @param {String} deviceType - device type slug or alias
+ * @param {String} version - the exact balenaOS version number
+ * @returns {Promise<fs.ReadStream>} image readable stream
+ *
+ * @example
+ * utils.getImage('raspberry-pi', '1.2.3').then (stream) ->
+ * 	stream.pipe(fs.createWriteStream('foo/bar.img'))
+ */
+const getImage = async (deviceType: string, version: string) => {
+	const imagePath = await getImagePath(deviceType, version);
+	const fs = await import('fs');
+	const stream = fs.createReadStream(imagePath) as ReturnType<
+		typeof fs.createReadStream
+	> & { mime: string };
+	// Default to application/octet-stream if we could not find a more specific mime type
+
+	const { getType } = await import('mime');
+	stream.mime = getType(imagePath) ?? 'application/octet-stream';
+	return stream;
+};
+
+/**
+ * @summary Get a writable stream for an image in the cache
+ * @function
+ * @protected
+ *
+ * @param {String} deviceType - device type slug or alias
+ * @param {String} version - the exact balenaOS version number
+ * @returns {Promise<fs.WriteStream & { persistCache: () => Promise<void>, removeCache: () => Promise<void> }>} image writable stream
+ *
+ * @example
+ * utils.getImageWritableStream('raspberry-pi', '1.2.3').then (stream) ->
+ * 	fs.createReadStream('foo/bar').pipe(stream)
+ */
+const getImageWritableStream = async (deviceType: string, version?: string) => {
+	const imagePath = await getImagePath(deviceType, version);
+
+	// Ensure the cache directory exists, to prevent
+	// ENOENT errors when trying to write to it.
+	const path = await import('path');
+	const { mkdirp } = await import('mkdirp');
+	await mkdirp(path.dirname(imagePath));
+
+	// Append .inprogress to streams, move them to the right location only on success
+	const inProgressPath = imagePath + '.inprogress';
+	const { promises, createWriteStream } = await import('fs');
+	type ImageWritableStream = ReturnType<typeof createWriteStream> &
+		Record<'persistCache' | 'removeCache', () => Promise<void>>;
+	const stream = createWriteStream(inProgressPath) as ImageWritableStream;
+
+	// Call .isCompleted on the stream
+	stream.persistCache = () => promises.rename(inProgressPath, imagePath);
+
+	stream.removeCache = () => promises.unlink(inProgressPath);
+
+	return stream;
+};
+
+type DownloadConfig = NonNullable<
+	Parameters<SDK.BalenaSDK['models']['os']['download']>[0]
+>;
+
+const doDownload = async (options: DownloadConfig) => {
+	const balena = getBalenaSdk();
+	const imageStream = await balena.models.os.download(options);
+	// Piping to a PassThrough stream is needed to be able
+	// to then pipe the stream to multiple destinations.
+	const { PassThrough } = await import('stream');
+	const pass = new PassThrough();
+	imageStream.pipe(pass);
+
+	// Save a copy of the image in the cache
+	const cacheStream = await getImageWritableStream(
+		options.deviceType,
+		options.version,
+	);
+
+	pass.pipe(cacheStream, { end: false });
+	pass.on('end', cacheStream.persistCache);
+
+	// If we return `pass` directly, the client will not be able
+	// to read all data from it after a delay, since it will be
+	// instantly piped to `cacheStream`.
+	// The solution is to create yet another PassThrough stream,
+	// pipe to it and return the new stream instead.
+	const pass2 = new PassThrough() as InstanceType<typeof PassThrough> & {
+		mime: string;
+	};
+	pass2.mime = imageStream.mime;
+	imageStream.on('progress', (state) => pass2.emit('progress', state));
+
+	imageStream.on('error', async (err) => {
+		await cacheStream.removeCache();
+		pass2.emit('error', err);
+	});
+
+	return pass.pipe(pass2);
+};
+
+/**
+ * @summary Get a device operating system image
+ * @function
+ * @public
+ *
+ * @description
+ * This function saves a copy of the downloaded image in the cache directory setting specified in [balena-settings-client](https://github.com/balena-io-modules/balena-settings-client).
+ *
+ * @param {String} deviceType - device type slug or alias
+ * @param {String} versionOrRange - can be one of
+ * * the exact version number,
+ * in which case it is used if the version is supported,
+ * or the promise is rejected,
+ * * a [semver](https://www.npmjs.com/package/semver)-compatible
+ * range specification, in which case the most recent satisfying version is used
+ * if it exists, or the promise is rejected,
+ * * `'latest'` in which case the most recent version is used, including pre-releases,
+ * * `'recommended'` in which case the recommended version is used, i.e. the most
+ * recent version excluding pre-releases, the promise is rejected
+ * if only pre-release versions are available,
+ * * `'default'` in which case the recommended version is used if available,
+ * or `latest` is used otherwise.
+ * Defaults to `'latest'`.
+ * @param {Object} options
+ * @param {boolean} options?.developmentMode
+ * @returns {Promise<NodeJS.ReadableStream>} image readable stream
+ *
+ * @example
+ * manager.get('raspberry-pi', 'default').then (stream) ->
+ * 	stream.pipe(fs.createWriteStream('foo/bar.img'))
+ */
+export const getStream = async (
+	deviceType: string,
+	versionOrRange: string,
+	options: Omit<DownloadConfig, 'deviceType' | 'version'> = {},
+) => {
+	if (versionOrRange == null) {
+		versionOrRange = 'latest';
+	}
+	const version = await resolveVersion(deviceType, versionOrRange);
+	const isFresh = await isImageFresh(deviceType, version);
+	const $stream = isFresh
+		? await getImage(deviceType, version)
+		: await doDownload({ ...options, deviceType, version });
+	// schedule the 'version' event for the next iteration of the event loop
+	// so that callers have a chance of adding an event handler
+	setImmediate(() =>
+		$stream.emit('balena-image-manager:resolved-version', version),
+	);
+	return $stream;
+};