plugin-http-resolver.ts

// *****************************************************************************
// Copyright (C) 2018 Red Hat, Inc. and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// http://www.eclipse.org/legal/epl-2.0.
//
// This Source Code may also be made available under the following Secondary
// Licenses when the conditions for such availability set forth in the Eclipse
// Public License v. 2.0 are satisfied: GNU General Public License, version 2
// with the GNU Classpath Exception which is available at
// https://www.gnu.org/software/classpath/license.html.
//
// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
// *****************************************************************************

import { injectable } from '@theia/core/shared/inversify';
import * as fs from 'fs';
import * as os from 'os';
import * as path from 'path';
import * as url from 'url';
import * as request from 'request';

import { PluginDeployerResolver, PluginDeployerResolverContext } from '../../common';

/**
 * Resolver that handle the http(s): protocol
 * http://path/to/my.plugin
 * https://path/to/my.plugin
 */
@injectable()
export class HttpPluginDeployerResolver implements PluginDeployerResolver {

    private unpackedFolder: string;

    constructor() {
        this.unpackedFolder = path.resolve(os.tmpdir(), 'http-remote');
        if (!fs.existsSync(this.unpackedFolder)) {
            fs.mkdirSync(this.unpackedFolder);
        }
    }

    /**
     * Grab the remote file specified by the given URL
     */
    async resolve(pluginResolverContext: PluginDeployerResolverContext): Promise<void> {

        // download the file
        return new Promise<void>((resolve, reject) => {

            // keep filename of the url
            const urlPath = pluginResolverContext.getOriginId();
            const link = url.parse(urlPath);
            if (!link.pathname) {
                reject(new Error('invalid link URI' + urlPath));
                return;
            }

            const dirname = path.dirname(link.pathname);
            const basename = path.basename(link.pathname);
            const filename = dirname.replace(/\W/g, '_') + ('-') + basename;
            const unpackedPath = path.resolve(this.unpackedFolder, path.basename(filename));

            const finish = () => {
                pluginResolverContext.addPlugin(pluginResolverContext.getOriginId(), unpackedPath);
                resolve();
            };

            // use of cache. If file is already there use it directly
            if (fs.existsSync(unpackedPath)) {
                finish();
                return;
            }
            const dest = fs.createWriteStream(unpackedPath);

            dest.addListener('finish', finish);
            request.get(pluginResolverContext.getOriginId())
                .on('error', err => {
                    reject(err);
                }).pipe(dest);
        });

    }

    /**
     * Handle only the plugins that starts with http or https:
     */
    accept(pluginId: string): boolean {
        return /^http[s]?:\/\/.*$/gm.test(pluginId);
    }
}