@cumulus/deployment/app/kes.js

Deployment templates for cumulus

/**
 * This module overrides the Kes Class and the Lambda class of Kes
 * to support specific needs of the Cumulus Deployment.
 *
 * Specifically, this module changes the default Kes Deployment in the following ways:
 *
 * - Adds the ability to add Cumulus Configuration for each Step Function Task
 *    - @fixCumulusMessageSyntax
 *    - @extractCumulusConfigFromSF
 * - Generates a public and private key to encrypt private information
 *    - @generateKeyPair
 *    - @uploadKeyPair
 *    - @crypto
 * - Creates Cumulus Message Templates for each Step Function Workflow
 *    - @template
 *    - @generateTemplates
 * - Adds Cumulus Message Adapter code to any Lambda Function that uses it
 * - Uploads the public/private keys and the templates to S3
 * - Restart Existing ECS tasks after each deployment
 * - Redeploy API Gateway endpoints after Each Deployment
 *
 */

'use strict';

function _asyncToGenerator(fn) { return function () { var gen = fn.apply(this, arguments); return new Promise(function (resolve, reject) { function step(key, arg) { try { var info = gen[key](arg); var value = info.value; } catch (error) { reject(error); return; } if (info.done) { resolve(value); } else { return Promise.resolve(value).then(function (value) { step("next", value); }, function (err) { step("throw", err); }); } } return step("next"); }); }; }

const cloneDeep = require('lodash.clonedeep');
const zipObject = require('lodash.zipobject');
const get = require('lodash.get');
const { Kes, utils } = require('kes');
const fs = require('fs-extra');
const Handlebars = require('handlebars');
const path = require('path');
const util = require('util');
const { sleep } = require('@cumulus/common/util');

const Lambda = require('./lambda');
const { validateConfig } = require('./configValidators');
const { crypto } = require('./crypto');
const { fetchMessageAdapter } = require('./adapter');
const { extractCumulusConfigFromSF, generateTemplates } = require('./message');

const fsWriteFile = util.promisify(fs.writeFile);

/**
 * A subclass of Kes class that overrides opsStack method.
 * The subclass checks whether the public/private keys are generated
 * and uploaded to the deployment bucket. If not, they are generated and
 * uploaded.
 *
 * After the successful deployment of a CloudFormation template, the subclass
 * generates and uploads payload and StepFunction templates and restarts ECS
 * tasks if there is an active cluster with running tasks.
 *
 * @class UpdatedKes
 */
class UpdatedKes extends Kes {
  /**
   * Overrides the default constructor. It updates the default
   * Lambda class and adds a git repository path for the cumulus
   * message adapter
   *
   * @param {Object} config - kes config object
   */
  constructor(config) {
    super(config);
    this.Lambda = Lambda;
    validateConfig(config);
    this.messageAdapterGitPath = `${config.repo_owner}/${config.message_adapter_repo}`;
  }

  /**
   * Redeploy the given api gateway (more info: https://docs.aws.amazon.com/apigateway/latest/developerguide/how-to-deploy-api.html)
   *
   * @param {string} name - the name of the api gateway deployment (used for logging)
   * @param {string} restApiId - the api gateway id
   * @param {string} stageName - the deployment stage name
   * @returns {Promise.<boolean>} returns true if successful
   */
  redeployApiGateWay(name, restApiId, stageName) {
    var _this = this;

    return _asyncToGenerator(function* () {
      const waitTime = 20;
      if (restApiId) {
        try {
          const apigateway = new _this.AWS.APIGateway();
          yield apigateway.createDeployment({ restApiId, stageName }).promise();
          console.log(`${name} endpoints with the id ${restApiId} redeployed.`);
        } catch (e) {
          if (e.message && e.message.includes('Too Many Requests')) {
            console.log(`Redeploying ${restApiId} was throttled. ` + `Another attempt will be made in ${waitTime} seconds`);
            yield sleep(waitTime * 1000);
            return _this.redeployApiGateWay(name, restApiId, stageName);
          }
          throw e;
        }
      }
      return true;
    })();
  }

  /**
   * Restart all active tasks in the clusters of a deployed
   * CloudFormation
   *
   * @param  {Object} config - Kes Config object
   * @returns {Promise} undefined
   */
  restartECSTasks(config) {
    var _this2 = this;

    return _asyncToGenerator(function* () {
      const ecs = new _this2.AWS.ECS();

      // only restart the tasks if the user has turned it on the config
      if (config.ecs.restartTasksOnDeploy) {
        try {
          let resources = [];
          const params = { StackName: config.stackName };
          while (true) {
            // eslint-disable-line no-constant-condition
            // eslint-disable-next-line no-await-in-loop
            const data = yield _this2.cf.listStackResources(params).promise();
            resources = resources.concat(data.StackResourceSummaries);
            if (data.NextToken) params.NextToken = data.NextToken;else break;
          }

          const clusters = resources.filter(function (resource) {
            return resource.ResourceType === 'AWS::ECS::Cluster';
          }).map(function (cluster) {
            return cluster.PhysicalResourceId;
          });

          for (let clusterCtr = 0; clusterCtr < clusters.length; clusterCtr += 1) {
            const cluster = clusters[clusterCtr];
            // eslint-disable-next-line no-await-in-loop
            const tasks = yield ecs.listTasks({ cluster }).promise();

            for (let taskCtr = 0; taskCtr < tasks.taskArns.length; taskCtr += 1) {
              const task = tasks.taskArns[taskCtr];
              console.log(`restarting ECS task ${task}`);
              // eslint-disable-next-line no-await-in-loop
              yield ecs.stopTask({
                task: task,
                cluster
              }).promise();
              console.log(`ECS task ${task} restarted`);
            }
          }
        } catch (err) {
          console.log(err);
        }
      }
    })();
  }

  /**
   * build CloudWatch alarm widgets
   *
   * @param {string[]} alarmNames list of alarm names
   * @param {Object} alarmTemplate widget template for alarm
   * @returns {Object[]} list of alarm widgets
   */
  buildAlarmWidgets(alarmNames, alarmTemplate) {
    return alarmNames.map(alarmName => {
      const alarm = cloneDeep(alarmTemplate);
      alarm.properties.title = alarmName;
      alarm.properties.annotations.alarms[0] = alarm.properties.annotations.alarms[0].replace('alarmTemplate', alarmName);
      return alarm;
    });
  }

  /**
  * Build list of buckets of desired type.
  *
  * @param {Object} buckets - config buckets
  * @param {string} bucketType - selected type.
  * @returns {string} - comma separated list of every bucket in buckets that matches bucketType.
  */
  collectBuckets(buckets, bucketType) {
    const matchingBuckets = Object.values(buckets).filter(bucket => bucket.type === bucketType).map(object => object.name);
    return new Handlebars.SafeString(matchingBuckets.toString());
  }

  /**
   * build CloudWatch dashboard based on the dashboard configuration and other configurations
   *
   * @param {Object} dashboardConfig dashboard configuration for creating widgets
   * @param {Object} ecs Elastic Container Service configuration including custom configuration
   * for alarms
   * @param {Object} es Elasticsearch configuration including configuration for alarms
   * @param {string} stackName stack name
   * @returns {string} returns dashboard body string
   */
  buildCWDashboard(dashboardConfig, ecs, es, stackName) {
    const alarmTemplate = dashboardConfig.alarmTemplate;

    // build ECS alarm widgets
    const ecsAlarmNames = [];
    if (ecs && ecs.services) {
      Object.keys(ecs.services).forEach(serviceName => {
        // default alarm
        const defaultAlarmName = `${stackName}-${serviceName}-TaskCountLowAlarm`;
        ecsAlarmNames.push(defaultAlarmName);
        // custom alarm
        if (ecs.services[serviceName].alarms) {
          Object.keys(ecs.services[serviceName].alarms).forEach(alarmName => {
            const name = `${stackName}-${serviceName}-${alarmName}Alarm`;
            ecsAlarmNames.push(name);
          });
        }
      });
    }

    const ecsAlarms = this.buildAlarmWidgets(ecsAlarmNames, alarmTemplate);

    // build ES alarm widgets
    let esWidgets = [];
    if (es && es.alarms) {
      const esAlarmNames = Object.keys(es.alarms).map(alarmName => `${stackName}-${es.name}-${alarmName}Alarm`);
      const esAlarms = this.buildAlarmWidgets(esAlarmNames, alarmTemplate);
      esWidgets = dashboardConfig.esHeader.concat(cloneDeep(dashboardConfig.alarmHeader), esAlarms, dashboardConfig.esWidgets);
    }

    // put all widgets together
    let x = 0;
    let y = 0;

    const widgets = [];
    const allWidgets = dashboardConfig.ecsHeader.concat(cloneDeep(dashboardConfig.alarmHeader), ecsAlarms, esWidgets);

    let previousWgHeight = 0;
    // place the widgets side by side until reach width 24
    allWidgets.forEach(widget => {
      if (x + widget.width > 24) {
        x = 0;
        y += previousWgHeight;
      }
      widgets.push(Object.assign(widget, { x, y }));
      x += widget.width;
      previousWgHeight = widget.height;
    });

    return JSON.stringify({ widgets });
  }

  /**
   * Override CF parse to add Handlebars template helpers
   *
   * @param  {string} cfFile - Filename
   * @returns {string}        - Contents of cfFile templated using Handlebars
   */
  parseCF(cfFile) {
    // Parent kes deployed into packages/deployment contains
    // Original registered helpers 'ifEquals', 'ifNotEquals', and 'ToJson'

    // Arrow functions cannot be used when registering Handlebars helpers
    // https://stackoverflow.com/questions/43932566/handlebars-block-expression-do-not-work

    Handlebars.registerHelper('collectBuckets', (buckets, bucketType) => this.collectBuckets(buckets, bucketType));

    Handlebars.registerHelper('buildCWDashboard', (dashboardConfig, ecs, es, stackName) => this.buildCWDashboard(dashboardConfig, ecs, es, stackName));

    Handlebars.registerHelper('ifPrivateApi', (configs, api, options) => {
      const privateApi = configs && configs[api] ? configs[api].private : false;
      return privateApi ? options.fn(this) : options.inverse(this);
    });

    Handlebars.registerHelper('getApiPortSuffix', (configs, api) => {
      if (configs && configs[api] && configs[api].port) {
        return `:${configs[api].port}/`;
      }
      return '/';
    });

    Handlebars.registerHelper('ifLogApiGatewayToCloudWatch', function ifLogApiGatewayToCloudWatch(configs, api, options) {
      const logApiGatewayToCloudWatch = configs && configs[api] ? configs[api].logApiGatewayToCloudWatch : false;
      return logApiGatewayToCloudWatch ? options.fn(this) : options.inverse(this);
    });

    Handlebars.registerHelper('ifDeployApi', (templateKey, deployDistribution, options) => templateKey !== 'CumulusApiDistribution' || deployDistribution ? options.fn(this) : options.inverse(this));

    return super.parseCF(cfFile);
  }

  /**
   * Override CF compilation to inject cumulus message adapter
   *
   * @returns {Promise} returns the promise of an AWS response object
   */
  compileCF() {
    const filename = this.config.message_adapter_filename || '';
    const customCompile = this.config.customCompilation || '';
    const kesBuildFolder = path.join(this.config.kesFolder, 'build');
    const unzipFolderName = path.basename(filename, '.zip');

    const src = path.join(process.cwd(), kesBuildFolder, filename);
    const dest = path.join(process.cwd(), kesBuildFolder, 'adapter', unzipFolderName);

    this.updateRulesConfig();

    // If custom compile configuration flag not set, skip custom compilation
    if (!customCompile) return super.compileCF();

    this.setParentOverrideConfigValues();

    // If not using message adapter, don't fetch it
    if (!filename) return this.superCompileCF();

    return fetchMessageAdapter(this.config.message_adapter_version, this.messageAdapterGitPath, filename, src, dest).then(() => {
      this.Lambda.messageAdapterZipFileHash = new this.Lambda(this.config).getHash(src);
      return this.superCompileCF();
    });
  }

  /**
   * Preprocess/update rules config to avoid deployment issues.
   *
   * Cloudwatch rules that are triggered by Cloudwatch Step Function events
   * should be restricted to run only for Step Functions within the current
   * deployment. Due to character limits for Cloudwatch rule definitions, we
   * may need to split up a rule into multiple rules so that we can ensure it
   * is only triggered by Step Functions in this deployment.
   */
  updateRulesConfig() {
    if (!this.config.rules || !this.config.stepFunctions) {
      return;
    }

    const { prefixNoDash, rules, stepFunctions } = this.config;
    const updatedRules = {};

    const initializeNewRule = rule => {
      const newRule = cloneDeep(rule);
      newRule.stateMachines = [];
      newRule.eventPattern.detail = newRule.eventPattern.detail || {};
      newRule.eventPattern.detail.stateMachineArn = [];
      return newRule;
    };

    Object.keys(rules).forEach(ruleName => {
      const rule = rules[ruleName];
      const eventSource = get(rule, 'eventPattern.source', []);

      // If this rule doesn't use Step Functions as a source, stop processing.
      if (!eventSource.includes('aws.states')) {
        updatedRules[ruleName] = rule;
        return;
      }

      const initialPatternLength = JSON.stringify(rule.eventPattern).length;
      // Pessimistically assume longest possible state machine ARN:
      //    80 = max state machine length
      //    64 = length of other ARN characters
      //    2 = two double quotes
      const arnLength = 80 + 64 + 2;
      // Determine how many state machines can be added as conditions to the eventPattern
      // before it would exceed the maximum allowed length of 2048 characters.
      const stateMachinesPerRule = Math.ceil((2048 - initialPatternLength) / arnLength);

      let stateMachinesCount = 0;
      let newRule = initializeNewRule(rule);
      let ruleNumber = 1;

      const stepFunctionNames = Object.keys(stepFunctions);
      stepFunctionNames.forEach(sfName => {
        stateMachinesCount += 1;

        if (stateMachinesCount >= stateMachinesPerRule) {
          stateMachinesCount = 0;
          newRule = initializeNewRule(rule);
          ruleNumber += 1;
        }

        const stateMachineName = `${prefixNoDash}${sfName}StateMachine`;
        const stateMachineArnRef = `\$\{${stateMachineName}\}`;

        newRule.stateMachines.push(stateMachineName);
        newRule.eventPattern.detail.stateMachineArn.push(stateMachineArnRef);

        updatedRules[`${ruleName}${ruleNumber}`] = newRule;
      });
    });

    this.config.rules = updatedRules;
  }

  /**
   * setParentConfigvalues - Overrides nested stack template with parent values
   * defined in the override_with_parent config key
   */
  setParentOverrideConfigValues() {
    if (!this.config.parent) return;
    const parent = this.config.parent;
    this.config.override_with_parent.forEach(value => {
      this.config[value] = parent[value] == null ? this.config[value] : parent[value];
    });
  }

  /**
   * Modified version of Kes superclass compileCF method
   *
   * Compiles a CloudFormation template in Yaml format.
   *
   * Reads the configuration yaml from `.kes/config.yml`.
   *
   * Writes the template to `.kes/cloudformation.yml`.
   *
   * Uses `.kes/cloudformation.template.yml` as the base template
   * for generating the final CF template.
   *
   * @returns {Promise} returns the promise of an AWS response object
   */
  superCompileCF() {
    var _this3 = this;

    return _asyncToGenerator(function* () {
      const lambda = new _this3.Lambda(_this3.config);

      // Process default dead letter queue configs  if this value is set
      if (_this3.config.processDefaultDeadLetterQueues) {
        _this3.addLambdaDeadLetterQueues();
      }

      // If the lambdaProcess is set on the subtemplate default configuration
      // then *build* the lambdas and populate the config object
      // else only populate the configuration object but do not rebuild
      // lhe lambda zips
      if (_this3.config.lambdaProcess) {
        _this3.config = yield lambda.process();
      } else {
        lambda.buildAllLambdaConfiguration('lambdas');
      }

      let cf;

      // Inject Lambda Alias values into configuration,
      // then update configured workflow lambda references
      // to reference the generated alias values
      if (_this3.config.useWorkflowLambdaVersions === true) {
        if (_this3.config.oldLambdaInjection === true) {
          lambda.buildAllLambdaConfiguration('workflowLambdas');
          yield _this3.injectOldWorkflowLambdaAliases();
        }
        if (_this3.config.injectWorkflowLambdaAliases === true) {
          _this3.injectWorkflowLambdaAliases();
        }
      }

      // Update workflowLambdas with generated hash values
      lambda.addWorkflowLambdaHashes();

      // if there is a template parse CF there first
      if (_this3.config.template) {
        const mainCF = _this3.parseCF(_this3.config.template.cfFile);

        // check if there is a CF over
        try {
          fs.lstatSync(_this3.config.cfFile);
          const overrideCF = _this3.parseCF(_this3.config.cfFile);

          // merge the the two
          cf = utils.mergeYamls(mainCF, overrideCF);
        } catch (e) {
          if (!e.message.includes('ENOENT')) {
            console.log(`compiling the override template at ${_this3.config.cfFile} failed:`);
            throw e;
          }
          cf = mainCF;
        }
      } else {
        cf = _this3.parseCF(_this3.config.cfFile);
      }
      const destPath = path.join(_this3.config.kesFolder, _this3.cf_template_name);

      console.log(`Template saved to ${destPath}`);
      return fsWriteFile(destPath, cf);
    })();
  }

  /**
   * Calls CloudFormation's update-stack or create-stack methods
   * Changed to support multi-template configs by checking for params sub-objects, i.e.:
   * params:
   *   app:
   *     - name: someName
   *       value: someValue
   *
   * @returns {Promise} returns the promise of an AWS response object
   */
  cloudFormation() {
    if (this.config.app && this.config.app.params) this.config.params = this.config.app.params;
    // Fetch db stack outputs to retrieve DynamoDBStreamARNs and ESDomainEndpoint
    return this.describeStack(this.config.dbStackName).then(r => {
      if (r && r.Stacks[0] && r.Stacks[0].Outputs) {
        r.Stacks[0].Outputs.forEach(o => this.config.params.push({
          name: o.OutputKey,
          value: o.OutputValue
        }));
      } else {
        throw new Error(`Failed to fetch outputs for db stack ${this.config.dbStackName}`);
      }
    }).then(() => super.cloudFormation());
  }

  /**
   * Updates lambda/sqs configuration to include an sqs dead letter queue
   * matching the lambdas's name (e.g. {lambda.name}DeadLetterQueue)
   * @returns {void} Returns nothing.
   */
  addLambdaDeadLetterQueues() {
    const lambdas = this.config.lambdas;
    Object.keys(lambdas).forEach(key => {
      const lambda = lambdas[key];
      if (lambda.namedLambdaDeadLetterQueue) {
        console.log(`Adding named dead letter queue for ${lambda.name}`);
        const queueName = `${lambda.name}DeadLetterQueue`;
        this.config.sqs[queueName] = {
          MessageRetentionPeriod: this.config.DLQDefaultMessageRetentionPeriod,
          visibilityTimeout: this.config.DLQDefaultTimeout
        };
        this.config.lambdas[lambda.name].deadletterqueue = queueName;
      }
    });
  }

  /**
   *
   * @param {Object} lambda - AWS lambda object
   * @param {Object} config - AWS listAliases configuration object.
   * @returns {Promise.Object[]} returns the promise of an array of AWS Alias objects
   */
  getAllLambdaAliases(lambda, config) {
    var _this4 = this;

    return _asyncToGenerator(function* () {
      const lambdaConfig = Object.assign({}, config);
      let aliasPage;
      try {
        aliasPage = yield lambda.listAliases(lambdaConfig).promise();
      } catch (err) {
        if (err.statusCode === 404) {
          return [];
        }
        throw err;
      }

      if (!aliasPage.NextMarker) {
        return aliasPage.Aliases;
      }
      const aliases = aliasPage.Aliases;
      lambdaConfig.Marker = aliasPage.NextMarker;

      return aliases.concat((yield _this4.getAllLambdaAliases(lambda, lambdaConfig)));
    })();
  }

  /**
   * Using the object configuration, this function gets the 'config.maxNumerOfRetainedLambdas'
   * number of most recent lambda alias names to retain in the 'Old Lambda Resources' section of
   * the LambdaVersion template, avoiding duplicates of items in the Current Lambda section.
   *
   * @returns {Promise.string[]} returns the promise of a list of alias metadata
   *          objects: keys (Name, humanReadableIdentifier)
   **/
  getRetainedLambdaAliasMetadata() {
    var _this5 = this;

    return _asyncToGenerator(function* () {
      const awsLambda = new _this5.AWS.Lambda();
      const cumulusAliasDescription = 'Cumulus AutoGenerated Alias';
      const configLambdas = _this5.config.workflowLambdas;
      const numberOfRetainedLambdas = _this5.config.maxNumberOfRetainedLambdas;

      let aliasMetadataObjects = [];

      const lambdaNames = Object.keys(configLambdas);
      const aliasListsPromises = lambdaNames.map((() => {
        var _ref = _asyncToGenerator(function* (lambdaName) {
          const listAliasesConfig = {
            MaxItems: 10000,
            FunctionName: `${_this5.config.stackName}-${lambdaName}`
          };
          return _this5.getAllLambdaAliases(awsLambda, listAliasesConfig);
        });

        return function (_x) {
          return _ref.apply(this, arguments);
        };
      })());

      const aliasLists = yield Promise.all(aliasListsPromises);
      const aliasListsObject = zipObject(lambdaNames, aliasLists);

      lambdaNames.forEach(function (lambdaName) {
        console.log(`Evaluating: ${lambdaName} for old versions/aliases to retain. `);
        const aliases = aliasListsObject[lambdaName];
        const cumulusAliases = aliases.filter(function (alias) {
          return alias.Description.includes(cumulusAliasDescription);
        });

        if (cumulusAliases.length === 0) return;

        cumulusAliases.sort(function (a, b) {
          return b.FunctionVersion - a.FunctionVersion;
        });
        const oldAliases = cumulusAliases.filter(function (alias) {
          return _this5.parseAliasName(alias.Name).hash !== configLambdas[lambdaName].hash;
        });
        const oldAliasMetadataObjects = oldAliases.map(function (alias) {
          return {
            name: alias.Name,
            humanReadableIdentifier: _this5.getHumanReadableIdentifier(alias.Description)
          };
        }).slice(0, numberOfRetainedLambdas);

        if (oldAliasMetadataObjects.length > 0) {
          console.log('Adding the following "old" versions to LambdaVersions:', `${JSON.stringify(oldAliasMetadataObjects.map(function (obj) {
            return obj.name;
          }))}`);
        }
        aliasMetadataObjects = aliasMetadataObjects.concat(oldAliasMetadataObjects);
      });
      return aliasMetadataObjects;
    })();
  }

  /**
   * Parses a passed in alias description field for a version string,
   * (e.g. `Cumulus Autogenerated Alias |version`)
   *
   * @param {string} description lambda alias description
   * @returns {string} Returns the human readable version or '' if no match is found
   */
  getHumanReadableIdentifier(description) {
    const descriptionMatch = description.match(/.*\|(.*)$/);
    if (!descriptionMatch) return '';
    return descriptionMatch[1] || '';
  }

  /**
   * Parses  Alias name properties into a results object
   *
   * @param {string} name - Cumulus created CF Lambda::Alias name parameter
   *                        in format Name-Hash,
   * @returns {Object} returns hash with name/value keys mapped to appropriate
   *                   matches and sets hash to null if no hash match in 'name'
   */
  parseAliasName(name) {
    const regExp = /^([^-]*)-([^-]*)$/;
    const regExpResults = regExp.exec(name);
    let hashValue = null;
    if (regExpResults[2]) hashValue = regExpResults[2];
    return { name: regExpResults[1], hash: hashValue };
  }

  /**
   * Uses getRetainedLambdaAliasMetadata to generate a list of lambda
   * aliases to save, then parses each name/hash pair to generate  CF template
   * configuration name: [hashes] and injects that into the oldLambdas config
   * key
   *
   * @returns {Promise.void} Returns nothing.
   */
  injectOldWorkflowLambdaAliases() {
    var _this6 = this;

    return _asyncToGenerator(function* () {
      const oldLambdaMetadataObjects = yield _this6.getRetainedLambdaAliasMetadata();
      const oldLambdas = {};

      oldLambdaMetadataObjects.forEach(function (obj) {
        const matchObject = _this6.parseAliasName(obj.name);
        if (matchObject.hash) {
          if (!oldLambdas[matchObject.name]) oldLambdas[matchObject.name] = { lambdaRefs: [] };
          oldLambdas[matchObject.name].lambdaRefs.push({
            hash: matchObject.hash,
            humanReadableIdentifier: obj.humanReadableIdentifier
          });
        }
      });
      _this6.config.oldLambdas = oldLambdas;
    })();
  }

  /**
   * Updates all this.config.stepFunctions state objects of type Task with
   * a LambdaFunction.ARN resource to refer to the a generated LambdaAlias
   * reference elsewhere in the template.
   *
   * Functions without a unique identifier (hash), and therefore no alias
   * will continue to utilize the original reference.
   *
   * @returns {void} Returns nothing.
   */
  injectWorkflowLambdaAliases() {
    console.log('Updating workflow Lambda ARN references to Lambda Alias references');
    Object.keys(this.config.stepFunctions).forEach(stepFunction => {
      const stepFunctionStateKeys = Object.keys(this.config.stepFunctions[stepFunction].States);
      stepFunctionStateKeys.forEach(stepFunctionState => {
        const stateObject = this.config.stepFunctions[stepFunction].States[stepFunctionState];

        if (stateObject.Type === 'Task' && stateObject.Resource.endsWith('LambdaFunction.Arn}')) {
          console.log(`Updating workflow ${stateObject.Resource} reference`);
          const lambdaAlias = this.lookupLambdaReference(stateObject.Resource);
          console.log(`Setting reference to ${lambdaAlias}`);
          stateObject.Resource = lambdaAlias;
        }
      });
    });
  }

  /**
   * Programatically evaluates a lambda ARN reference and returns the expected template reference.
   * This will either be the unqualified Lambda reference if unique identifier exists, or a
   * reference to the expected LambdaAliasOutput key from the LambdaVersions subtemplate.
   *
   * @param {string} stateObjectResource - CF template resource reference for a state function
   * @returns {string} The correct reference to the lambda function, either a hashed alias
   * reference or the passed in resource if hashing/versioning isn't possible for this resource
   * @throws {Error} Throws an error if the passed in stateObjectResource isn't a LambdaFunctionArn
   * reference
   */
  lookupLambdaReference(stateObjectResource) {
    let lambdaKey;
    const regExp = /^\$\{(.*)LambdaFunction.Arn/;
    const matchArray = regExp.exec(stateObjectResource);

    if (matchArray) {
      lambdaKey = matchArray[1];
    } else {
      console.log(`Invalid workflow configuration, ${stateObjectResource} ` + 'is not a valid Lambda ARN');
      throw new Error(`Invalid stateObjectResource: ${stateObjectResource}`);
    }
    const lambdaHash = this.config.lambdas[lambdaKey].hash;
    // If a lambda resource doesn't have a hash, refer directly to the function ARN
    if (!lambdaHash) {
      console.log(`No unique identifier for ${lambdaKey}, referencing ${stateObjectResource}`);
      return stateObjectResource;
    }

    return `\$\{${lambdaKey}LambdaAliasOutput\}`;
  }

  uploadTaskReaper() {
    return this.s3.putObject({
      Bucket: this.bucket,
      Key: `${this.stack}/deployment-staging/task-reaper.sh`,
      Body: fs.createReadStream(path.join(__dirname, '..', 'task-reaper.sh'))
    }).promise();
  }

  /**
   * Override opsStack method.
   *
   * @returns {Promise} aws response
   */
  opsStack() {
    // check if public and private key are generated
    // if not generate and upload them
    const apis = {};

    // remove config variable from all workflow steps
    // and keep them in a separate variable.
    // this is needed to prevent StepFunction deployment from crashing
    this.config = extractCumulusConfigFromSF(this.config);

    return crypto(this.stack, this.bucket, this.s3).then(() => this.uploadTaskReaper()).then(() => super.opsStack()).then(() => this.describeCF()).then(r => {
      const outputs = r.Stacks[0].Outputs;

      const urls = {
        Api: 'token',
        Distribution: 'redirect'
      };
      console.log('\nHere are the important URLs for this deployment:\n');
      outputs.forEach(o => {
        if (Object.keys(urls).includes(o.OutputKey)) {
          console.log(`${o.OutputKey}: `, o.OutputValue);
          console.log('Add this url to URS: ', `${o.OutputValue}${urls[o.OutputKey]}`, '\n');

          if (o.OutputKey === 'Distribution') {
            this.config.distribution_endpoint = o.OutputValue;
          }
        }

        switch (o.OutputKey) {
          case 'ApiId':
            apis.api = o.OutputValue;
            break;
          case 'DistributionId':
            apis.distribution = o.OutputValue;
            break;
          case 'ApiStage':
            apis.stageName = o.OutputValue;
            break;
          default:
          //nothing
        }
      });

      return generateTemplates(this.config, outputs, this.uploadToS3.bind(this));
    }).then(() => this.restartECSTasks(this.config)).then(() => this.redeployApiGateWay('api', apis.api, apis.stageName)).then(() => this.redeployApiGateWay('distribution', apis.distribution, apis.stageName)).catch(e => {
      console.log(e);
      throw e;
    });
  }
}

module.exports = UpdatedKes;