capability-sdk/index.js

Capability SDK for Node.js

/*
 * Copyright 2017-2019 Capability LLC. All Rights Reserved.
 *
 * 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.
 */
"use strict";

const CapabilityURI = require("capability-uri");
const concat = require("concat-stream");
const events = require("events");
const https = require("https");
const pkg = require("./package.json");
const util = require("util");

const CapabilitySDK = module.exports = function(config = {})
{
    if (!(this instanceof CapabilitySDK))
    {
        return new CapabilitySDK(config);
    }
    const self = this;
    events.EventEmitter.call(self);

    self._config = config;

    self.name = pkg.name;
    self.version = pkg.version;
};

util.inherits(CapabilitySDK, events.EventEmitter);

CapabilitySDK.version = pkg.version;

/*
  * `capability`: _Capability URI_ Capability to use.
  * `options`: _Object_ HTTPS request options, if any. Hostname, port, and
      authorization header will be overriden by the specified `capability`.
  * `callback`: _Function_ `(resp) => {}` _(Default: undefined)_ Optional
      callback that will be added as one time listener for the "response" event.
  * Return: _http.ClientRequest_ Node.js HTTP ClientRequest object.
*/
CapabilitySDK.request = (capability, options, callback) =>
{
    const uri = CapabilityURI.parse(capability);
    if (!uri.authority)
    {
        throw new Error(`Unable to determine capability authority to use for HTTPS request`);
    }
    const uriParts = uri.authority.split(":");
    const reqOptions = Object.assign({}, options);
    reqOptions.hostname = uriParts[0];
    if (uriParts[1])
    {
        reqOptions.port = uriParts[1];
    }
    reqOptions.headers = reqOptions.headers || {};
    reqOptions.headers = Object.keys(reqOptions.headers)
        .map(key => [key, reqOptions.headers[key]])
        .filter(([name, value]) => name.toLowerCase() != "authorization")
        .reduce((headers, [name, value]) =>
            {
                headers[name] = value;
                return headers;
            },
            {}
        );
    reqOptions.headers.authorization = `Bearer ${uri.capabilityToken.serialize()}`;
    reqOptions.agent = new https.Agent(reqOptions);
    return https.request(reqOptions, callback);
};

/*
  * `capability`: _Capability URI_ Capability to use.
  * `options`: _Object_ HTTPS request options, if any. Hostname, port, and
      authorization header will be overriden by the specified `capability`.
  * `data`: _String_ _(Default: undefined)_ Request data to send, if any.
  * `callback`: _Function_ `(error, resp) => {}`
    * `error`: _Error_ Error, if any.
    * `resp`: _Object_ Response object.
*/
CapabilitySDK.requestReply = (capability, options, data, callback) =>
{
    const req = CapabilitySDK.request(capability, options);
    req.on("response", resp =>
        {
            resp.pipe(concat({encoding: "string"}, response =>
                {
                    if (response.length > 0)
                    {
                        try
                        {
                            response = JSON.parse(response);
                        }
                        catch (e)
                        {
                            return callback(
                                {
                                    error: "Parsing response failed",
                                    statusCode: resp.statusCode,
                                    message: `error parsing "${response}"`
                                }
                            );
                        }
                    }
                    if (resp.statusCode >= 400)
                    {
                        return callback(
                            {
                                error: response.error,
                                statusCode: resp.statusCode,
                                message: response.message
                            }
                        );
                    }
                    if (response.statusCode >= 400 || response.error)
                    {
                        return callback(response);
                    }
                    return callback(undefined, response);
                }
            ));
        }
    );
    req.on("error", error =>
        {
            return callback(
                {
                    error: "Request failed",
                    message: `Request failed due to ${error}`,
                    details: error
                }
            );
        }
    );
    if (data)
    {
        req.write(data);
    }
    req.end();
};

CapabilitySDK.SERVICES =
[
    "certificate-manager", "media", "membrane"
];

CapabilitySDK.CertificateManager = require("./services/certificateManager.js");
CapabilitySDK.Media = require("./services/media.js");
CapabilitySDK.Membrane = require("./services/membrane.js");