@webscale-networks/cloudedge-handlers/execution_context/lambda/src/serverless.js

Webscale Networks CloudEDGE Handlers for cloud-agnostic edge function execution

'use strict';
const fs = require('fs');
const path = require('path');
const _ = require('lodash');

const handlers = require('../../utils/src/handlers.js');
const utils = require('./utils.js');

// event will contain the payload sent by the proxy with the following
// structure -
//  {
//    method: string, // Ex: GET, POST
//    peerAddress: string, // Client ip address
//    query: string,
//    path: string,
//    host: string,
//    protocol: string, // HTTP or HTTPS
//    wsapp: string, // Application api id
//    body: string, // Always Base64 encoded
//    headers: {
//      key: [value1, value2]
//    }
//  }
exports.handler = async (event) => {
    const rawHandlers = fs.readFileSync(
        path.resolve( __dirname, '../../../handlers.json'),
    );
    const config = JSON.parse(rawHandlers);

    // Convert request into generic Webscale object.
    const wReq = _.cloneDeep(event);

    let result = null;
    if (config['serverlessHandlers']) {
        result = await handlers.run(
            wReq, null, config['serverlessHandlers'], config,
        );
    } else {
        console.log('Serverless handler not specified.');
    }

    if (isSet(result)) {
        if (result.error) {
            if (result.response) {
                return this._webscaleToProxyResponse(result.response);
            } else {
                console.log('Received error without response. Error - ', result.error);
                return utils.defaultServerlessErrorResponse();
            }
        } else {
            return this._webscaleToProxyResponse(result.response);
        }
    } else {
        console.log('The handler did not return a result, sending default error response');
        return utils.defaultServerlessErrorResponse();
    }
};

// Converts a Webscale response into a response that can be
// returned to proxy.
exports._webscaleToProxyResponse = (wResponse) => {
  let response = {
    status: wResponse.statusCode.toString(),
    headers: wResponse.headers || {},
  };
  if (wResponse.body && wResponse.body.data) {
      response['body'] = Buffer.from(wResponse.body.data).toString('base64');
      response['bodyEncoding'] = wResponse.body.encoding;
  }
  return response;
};

const isSet = (result) => {
    return result &&
        (_.has(result, 'error') ||
            _.has(result, 'response'));
};