/**
 * @name init
 * @summary Initialize Hydra with config object.
 * @param {object} config - configuration object containing hydra specific keys/values
 * @return {object} promise - resolving if init success or rejecting
 otherwise
 */
init(config)

/**
* @name ready
* @summary returns promise that resolves when initialization is complete
* @return {object} promise - resolving if init success or rejecting otherwise
*/
ready()

/**
* @name _shutdown
* @summary Shutdown hydra safely.
*/
shutdown()

/**
 * @name registerService
 * @summary Registers this machine as a Hydra instance.
 * @description This is an optional call as this module might just be used to monitor and query instances.
 * @return {object} promise - resolving if registration success or rejecting otherwise
 */
registerService()

/**
 * @name getServiceName
 * @summary Retrieves the service name of the current instance.
 * @throws Throws an error if this machine isn't a instance.
 * @return {string} serviceName - returns the service name.
 */
getServiceName()

/**
 * @name getServiceNodes
 * @summary Retrieve a list of services even if inactive.
 * @return {promise} promise - returns a promise
 */
getServiceNodes()

/**
 * @name getServices
 * @summary Retrieve a list of available instance services.
 * @return {promise} promise - returns a promise which resolves to an array of objects.
 */
getServices()

/**
 * @name findService
 * @summary Find a service.
 * @param {string} name - service name - note service name is case insensitive
 * @return {promise} promise - which resolves with service
 */
findService(name)

/**
 * @name getServicePresence
 * @summary Retrieve a service / instance's presence info.
 * @param {string} name - service name - note service name is case insensitive
 * @return {promise} promise - which resolves with service presence
 */
getServicePresence(name)

/**
 * @name hasServicePresence
 * @summary Indicate if a service has presence.
 * @description Indicates if a service has presence, meaning the 
 *              service is running in at least one node.
 * @param {string} name - service name - note service name is case insensitive
 * @return {promise} promise - which resolves with TRUE if presence is found, FALSE otherwise
*/
hasServicePresence(name)

/**
* @name getInstanceID
* @summary Return the instance id for this process
* @return {number} id - instanceID
*/
getInstanceID()

/**
 * @name sendToHealthLog
 * @summary Log a message to the service instance's health log queue.
 * @private
 * @throws Throws an error if this machine isn't a instance.
 * @param {string} type - type of message ('error', 'info', 'debug' or user defined)
 * @param {string} message - message to log
 */
sendToHealthLog(type, message)

/**
 * @name getServiceHealthLog
 * @summary Get this service's health log.
 * @throws Throws an error if this machine isn't a instance
 * @param {string} name - name of instance, use getName() if current service is the target.
 *                        note service name is case insensitive.
 * @return {promise} promise - resolves to log entries
 */
getServiceHealthLog(name)

/**
 * @name getHealth
 * @summary Retrieve service health info.
 * @private
 * @return {object} obj - object containing service info
 */
getHealth()

/**
 * @name getServiceHealthAll
 * @summary Retrieve the health status of all instance services.
 * @return {promise} promise - resolves with an array of objects containing instance health information.
 */
getServiceHealthAll()

/**
 * @name createUMFMessage
 * @summary Create a UMF style message.
 * @description This is a helper function which helps format a UMF style message.
 *              The caller is responsible for ensuring that required fields such as
 *              "to", "from" and "body" are provided either before or after using
 *              this function.
 * @param {object} message - optional message overrides.
 * @return {object} message - a UMF formatted message.
 */
createUMFMessage(message)

/**
 * @name makeAPIRequest
 * @summary Makes an API request to a hydra service.
 * @description If the service isn't present and the message object has its
 *              message.body.fallbackToQueue value set to true, then the
 *              message will be sent to the services message queue.
 * @param {object} message - UMF formatted message
 * @return {promise} promise - response from API in resolved promise or
 *                   error in rejected promise.
 */
makeAPIRequest(message)

/**
 * @name sendMessage
 * @summary Sends a message to all present instances of a  hydra service.
 * @param {string | object} message - Plain string or UMF formatted message object
 * @return {promise} promise - resolved promise if sent or
 *                   error in rejected promise.
 */
sendMessage(message)

/**
 * @name sendReplyMessage
 * @summary Sends a reply message based on the original message received.
 * @param {object} originalMessage - UMF formatted message object
 * @param {object} messageResponse - UMF formatted message object
 * @return {object} promise - resolved promise if sent or
 *                   error in rejected promise.
 */
sendReplyMessage(originalMessage, messageResponse)

/**
* @name registerRoutes
* @summary Register routes
* @note Routes must be formatted as UMF To routes. https://github.com/cjus/umf#%20To%20field%20(routing)
* @param {array} routes - array of routes
* @return {object} Promise - resolving or rejecting
*/
registerRoutes(routes)

/**
* @name getAllServiceRoutes
* @summary Retrieve all service routes.
* @return {object} Promise - resolving to an object with keys and arrays of routes
*/
getAllServiceRoutes()

/**
* @name matchRoute
* @summary Matches a route path to a list of registered routes
* @private
* @param {string} routePath - a URL path to match
* @return {boolean} match - true if match, false if not
*/
matchRoute(routePath)

/**
* @name queueMessage
* @summary Queue a message
* @param {object} message - UMF message to queue
* @return {promise} promise - resolving to the message that was queued or a rejection.
*/
queueMessage(message)

/**
* @name getQueuedMessage
* @summary Retrieve a queued message
* @param {string} serviceName who's queue might provide a message
* @return {promise} promise - resolving to the message that was dequeued or a rejection.
*/
getQueuedMessage(serviceName)

/**
* @name markQueueMessage
* @summary Mark a queued message as either completed or not
* @param {object} message - message in question
* @param {boolean} completed - (true / false)
* @param {string} reason - if not completed this is the reason processing failed
* @return {promise} promise - resolving to the message that was dequeued or a rejection.
*/
markQueueMessage(message, completed, reason)

$ npm install hydra-express

'use strict';
const config = require('./config/properties').value;
const version = require('./package.json').version;
const hydraExpress = require('hydra-express');
function registerRoutesCallback() {
  hydraExpress.registerRoutes({
    '/v1/offers': require('./offers-v1-api')
  });
}
function registerMiddlewareCallback() {
  let app = hydraExpress.getExpressApp();
  app.use((req, res, next) => {
    console.log('req.headers', req.headers);
    next();
  });
}
hydraExpress.init(config, version, registerRoutesCallback, registerMiddlewareCallback)
  .then((serviceInfo) => {
    console.log('serviceInfo', serviceInfo);
  })
  .catch((err) => {
    console.log('err', err);
  });

hydraExpress.log('error', message);

$ sudo npm install -g hydra-cli

$ hydra-cli
hydra-cli version 0.5.7
Usage: hydra-cli command [parameters]
See docs at: https://github.com/flywheelsports/hydra-cli
A command line interface for Hydra services
Commands:
  help                         - this help list
  cfg pull label               - download configuration file
  cfg push label filename      - update configuration file
  cfg list serviceName         - display a list of config versions
  config instanceName          - configure connection to redis
  config list                  - display current configuration
  use instanceName             - name of redis instance to use
  health [serviceName]         - display service health
  healthlog serviceName        - display service health log
  message create               - create a message object
  message send message.json    - send a message
  nodes [serviceName]          - display service instance nodes
  refresh node list            - refresh list of nodes
  rest path [payload.json]     - make an HTTP RESTful call to a service
  routes [serviceName]         - display service API routes
  services [serviceName]       - display list of services
  shell                        - display command to open redis shell

$ hydra-cli config local

$ hydra-cli use staging

$ hydra-cli config list

HYDRA_REDIS_URL='redis://10.0.0.2:6379/15'
HYDRA_SERVICE='myservice:0.12.1'

$ hydra-cli cfg list myservice

$ hydra-cli cfg pull myservice:0.12.1

$ hydra-cli cfg pull myservice:0.12.1 
>
 config.json

$ hydra-cli cfg push myservice:0.12.2 config.json

$ hydra-cli nodes

hydra-cli routes

$ hydra-cli health

$ hydra-cli health myservice

$ hydra-cli refresh

$ hydra-cli shell

$(hydra-cli shell)

$ sudo npm install -g yo generator-fwsp-hydra

$ yo fwsp-hydra
? Name of the service (`-service` will be appended automatically) hello

Done!
'cd example-service' then 'npm install' and 'npm start'

{
  "environment": "development",
  "hydra": {
    "serviceName": "hello-service",
    "serviceIP": "",
    "servicePort": 5000,
    "serviceType": "hello",
    "serviceDescription": "says hello",
    "redis": {
      "url": "redis://127.0.0.1:6379/15"
    }
  }
}