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lens/src/extensions/extension-discovery.ts
Roman d050d6c0ea fix validation
Signed-off-by: Roman <ixrock@gmail.com>
2020-11-24 17:04:39 +02:00

329 lines
11 KiB
TypeScript

import chokidar from "chokidar";
import { EventEmitter } from "events";
import fs from "fs-extra";
import os from "os";
import path from "path";
import { getBundledExtensions } from "../common/utils/app-version";
import logger from "../main/logger";
import { extensionInstaller, PackageJson } from "./extension-installer";
import type { LensExtensionId, LensExtensionManifest } from "./lens-extension";
export interface InstalledExtension {
readonly manifest: LensExtensionManifest;
readonly manifestPath: string;
readonly isBundled: boolean; // defined in project root's package.json
isEnabled: boolean;
}
const logModule = "[EXTENSION-DISCOVERY]";
export const manifestFilename = "package.json";
/**
* Returns true if the lstat is for a directory-like file (e.g. isDirectory or symbolic link)
* @param lstat the stats to compare
*/
const isDirectoryLike = (lstat: fs.Stats) => lstat.isDirectory() || lstat.isSymbolicLink();
/**
* Discovers installed bundled and local extensions from the filesystem.
* Also watches for added and removed local extensions by watching the directory.
* Uses ExtensionInstaller to install dependencies for all of the extensions.
* This is also done when a new extension is copied to the local extensions directory.
* .init() must be called to start the directory watching.
* The class emits events for added and removed extensions:
* - "add": When extension is added. The event is of type InstalledExtension
* - "remove": When extension is removed. The event is of type LensExtensionId
*/
export class ExtensionDiscovery {
protected bundledFolderPath: string;
private loadStarted = false;
// This promise is resolved when .load() is finished.
// This allows operations to be added after .load() success.
private loaded: Promise<void>;
// These are called to either resolve or reject this.loaded promise
private resolveLoaded: () => void;
private rejectLoaded: (error: any) => void;
public events: EventEmitter;
constructor() {
this.loaded = new Promise((resolve, reject) => {
this.resolveLoaded = resolve;
this.rejectLoaded = reject;
});
this.events = new EventEmitter();
}
// Each extension is added as a single dependency to this object, which is written as package.json.
// Each dependency key is the name of the dependency, and
// each dependency value is the non-symlinked path to the dependency (folder).
protected packagesJson: PackageJson = {
dependencies: {}
};
get localFolderPath(): string {
return path.join(os.homedir(), ".k8slens", "extensions");
}
get packageJsonPath() {
return path.join(extensionInstaller.extensionPackagesRoot, manifestFilename);
}
get inTreeTargetPath() {
return path.join(extensionInstaller.extensionPackagesRoot, "extensions");
}
get inTreeFolderPath(): string {
return path.resolve(__static, "../extensions");
}
get nodeModulesPath(): string {
return path.join(extensionInstaller.extensionPackagesRoot, "node_modules");
}
/**
* Initializes the class and setups the file watcher for added/removed local extensions.
*/
init() {
this.watchExtensions();
}
/**
* Watches for added/removed local extensions.
* Dependencies are installed automatically after an extension folder is copied.
*/
async watchExtensions() {
logger.info(`${logModule} watching extension add/remove in ${this.localFolderPath}`);
// Wait until .load() has been called and has been resolved
await this.loaded;
// chokidar works better than fs.watch
chokidar.watch(this.localFolderPath, {
// Dont watch recursively into subdirectories
depth: 0,
// Try to wait until the file has been completely copied.
// The OS might emit an event for added file even it's not completely written to the filesysten.
awaitWriteFinish: {
// Wait 300ms until the file size doesn't change to consider the file written.
// For a small file like package.json this should be plenty of time.
stabilityThreshold: 300
}
})
// Extension add is detected by watching "<extensionDir>package.json" add
.on("add", this.handleWatchFileAdd)
// Extension remove is detected by watching <extensionDir>" unlink
.on("unlinkDir", this.handleWatchUnlinkDir);
}
handleWatchFileAdd = async (filePath: string) => {
if (path.basename(filePath) === manifestFilename) {
try {
const absPath = path.dirname(filePath);
// this.loadExtensionFromPath updates this.packagesJson
const extension = await this.loadExtensionFromPath(absPath);
if (extension) {
// Install dependencies for the new extension
await this.installPackages();
logger.info(`${logModule} Added extension ${extension.manifest.name}`);
this.events.emit("add", extension);
}
} catch (error) {
console.error(error);
}
}
};
handleWatchUnlinkDir = async (filePath: string) => {
// filePath is the non-symlinked path to the extension folder
// this.packagesJson.dependencies value is the non-symlinked path to the extension folder
// LensExtensionId in extension-loader is the symlinked path to the extension folder manifest file
// Check that the removed path is directly under this.localFolderPath
// Note that the watcher can create unlink events for subdirectories of the extension
const extensionFolderName = path.basename(filePath);
if (path.relative(this.localFolderPath, filePath) === extensionFolderName) {
const extensionName: string | undefined = Object
.entries(this.packagesJson.dependencies)
.find(([_name, extensionFolder]) => filePath === extensionFolder)?.[0];
if (extensionName !== undefined) {
delete this.packagesJson.dependencies[extensionName];
// Reinstall dependencies to remove the extension from package.json
await this.installPackages();
// The path to the manifest file is the lens extension id
// Note that we need to use the symlinked path
const lensExtensionId = path.join(this.nodeModulesPath, extensionName, "package.json");
logger.info(`${logModule} removed extension ${extensionName}`);
this.events.emit("remove", lensExtensionId as LensExtensionId);
} else {
logger.warn(`${logModule} extension ${extensionFolderName} not found, can't remove`);
}
}
};
async load(): Promise<Map<LensExtensionId, InstalledExtension>> {
if (this.loadStarted) {
// The class is simplified by only supporting .load() to be called once
throw new Error("ExtensionDiscovery.load() can be only be called once");
}
this.loadStarted = true;
try {
logger.info(`${logModule} loading extensions from ${extensionInstaller.extensionPackagesRoot}`);
if (fs.existsSync(path.join(extensionInstaller.extensionPackagesRoot, "package-lock.json"))) {
await fs.remove(path.join(extensionInstaller.extensionPackagesRoot, "package-lock.json"));
}
try {
await fs.access(this.inTreeFolderPath, fs.constants.W_OK);
this.bundledFolderPath = this.inTreeFolderPath;
} catch {
// we need to copy in-tree extensions so that we can symlink them properly on "npm install"
await fs.remove(this.inTreeTargetPath);
await fs.ensureDir(this.inTreeTargetPath);
await fs.copy(this.inTreeFolderPath, this.inTreeTargetPath);
this.bundledFolderPath = this.inTreeTargetPath;
}
await fs.ensureDir(this.nodeModulesPath);
await fs.ensureDir(this.localFolderPath);
const extensions = await this.loadExtensions();
// resolve the loaded promise
this.resolveLoaded();
return extensions;
} catch (error) {
this.rejectLoaded(error);
}
}
protected async getByManifest(manifestPath: string, { isBundled = false, isEnabled = isBundled }: {
isBundled?: boolean;
isEnabled?: boolean;
} = {}): Promise<InstalledExtension | null> {
let manifestJson: LensExtensionManifest;
try {
// check manifest file for existence
fs.accessSync(manifestPath, fs.constants.F_OK);
manifestJson = __non_webpack_require__(manifestPath);
this.packagesJson.dependencies[manifestJson.name] = path.dirname(manifestPath);
return {
manifestPath: path.join(this.nodeModulesPath, manifestJson.name, "package.json"),
manifest: manifestJson,
isBundled,
isEnabled,
};
} catch (error) {
logger.error(`${logModule}: can't install extension at ${manifestPath}: ${error}`, { manifestJson });
return null;
}
}
async loadExtensions(): Promise<Map<LensExtensionId, InstalledExtension>> {
const bundledExtensions = await this.loadBundledExtensions();
const localExtensions = await this.loadFromFolder(this.localFolderPath);
await this.installPackages();
const extensions = bundledExtensions.concat(localExtensions);
return new Map(extensions.map(ext => [ext.manifestPath, ext]));
}
/**
* Write package.json to file system and install dependencies.
*/
installPackages() {
return extensionInstaller.installPackages(this.packageJsonPath, this.packagesJson);
}
async loadBundledExtensions() {
const extensions: InstalledExtension[] = [];
const folderPath = this.bundledFolderPath;
const bundledExtensions = getBundledExtensions();
const paths = await fs.readdir(folderPath);
for (const fileName of paths) {
if (!bundledExtensions.includes(fileName)) {
continue;
}
const absPath = path.resolve(folderPath, fileName);
const extension = await this.loadExtensionFromPath(absPath, { isBundled: true });
if (extension) {
extensions.push(extension);
}
}
logger.debug(`${logModule}: ${extensions.length} extensions loaded`, { folderPath, extensions });
return extensions;
}
async loadFromFolder(folderPath: string): Promise<InstalledExtension[]> {
const bundledExtensions = getBundledExtensions();
const extensions: InstalledExtension[] = [];
const paths = await fs.readdir(folderPath);
for (const fileName of paths) {
// do not allow to override bundled extensions
if (bundledExtensions.includes(fileName)) {
continue;
}
const absPath = path.resolve(folderPath, fileName);
if (!fs.existsSync(absPath)) {
continue;
}
const lstat = await fs.lstat(absPath);
// skip non-directories
if (!isDirectoryLike(lstat)) {
continue;
}
const extension = await this.loadExtensionFromPath(absPath);
if (extension) {
extensions.push(extension);
}
}
logger.debug(`${logModule}: ${extensions.length} extensions loaded`, { folderPath, extensions });
return extensions;
}
/**
* Loads extension from absolute path, updates this.packagesJson to include it and returns the extension.
*/
async loadExtensionFromPath(absPath: string, { isBundled = false, isEnabled = isBundled }: {
isBundled?: boolean;
isEnabled?: boolean;
} = {}): Promise<InstalledExtension | null> {
const manifestPath = path.resolve(absPath, manifestFilename);
return this.getByManifest(manifestPath, { isBundled, isEnabled });
}
}
export const extensionDiscovery = new ExtensionDiscovery();