How to send UFM message from non-hydra server to hydra micraservice?

[emjimadhu]

HI all, First of all thanks for this awesome service.

I have a expressjs app (non hydra), and two microservice (hydra-express). i want to send a request to microservice from express app. i tried sample message from documentation. but it gives error. can you guys point me out how to implement message from non-hydra app to hydra microservice?

[sjmcdowall]

Hello Em Ji Madhu!

I am new to this as well, so this could be a good learning experience as I try to understand all the magic here too! :)

From all the documentation I have read what you want to do should be pretty easy so that is good!

Can you share the code you are using to try to invoke the service and the output from when you run the service (it has nice information) and of course what actual error code are you getting?

You can also try to access the service from the command line via “curl” — have you tried that?

Cheers!

/Steve

On Feb 15, 2018, at 1:32 AM, Em Ji Madhu notifications@github.com wrote:

HI all, First of all thanks for this awesome service.

I have a expressjs app (non hydra), and two microservice (hydra-express). i want to send a request to microservice from express app. i tried sample message from documentation. but it gives error. can you guys point me out how to implement message from non-hydra app to hydra microservice?

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[cjus]

@emjimadhu You can simply send an HTTP RESTful request from an expressjs app to any hydra-express app which has exposed an endpoint. The body of that message (assuming POST) can be a UMF message. Sending messages between hydra/hydra-express apps only needs the hydra.sendMessage call.

If you'd like to send websocket messages to hydra-express apps from other services you can also do that via our Hydra-Router service. See: https://www.hydramicroservice.com/docs/tools/hydra-router/

If you'd like to engage with others using Hydra consider joining our Slack channel. More info here: https://github.com/flywheelsports/hydra#join-us-on-slack

[emjimadhu]

@sjmcdowall @cjus thanks for the reply guys.

@sjmcdowall here is what i am doing

in my routes

`const hydra = require('hydra') const consts = require(__base + 'utils/consts')

module.exports = (req, res) => { hydra.init(consts.hydra) .then(() => { console.log('hydra initiated') return hydra.findService('firebase-service') }) .then((service) => { console.log(service) res.send(service) }) .catch((error) => { console.log(error) res.send(error) }) }`

and this is my config file

module.exports = { port: process.env.PORT || 1337, hydra: { serviceName: '', serviceDescription: '', serviceIP: '', servicePort: 0, serviceType: '', redis: { host: '127.0.0.1', port: 6379, db: 15 } } }

@sjmcdowall @cjus i followed this guide to intialize hydra in non-service app https://www.hydramicroservice.com/docs/hydra-core/getting-started.html

as you guys stated in their i left all the service related fields as empty strings except redis.

when i run this code i get this message.

Error: Config missing serviceName or servicePort at Promise (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/hydra/index.js:185:16) at Promise._execute (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/hydra/node_modules/bluebird/js/release/debuggability.js:300:9) at Promise._resolveFromExecutor (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/hydra/node_modules/bluebird/js/release/promise.js:483:18) at new Promise (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/hydra/node_modules/bluebird/js/release/promise.js:79:10) at IHydra.init (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/hydra/index.js:115:25) at IHydra.init (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/hydra/index.js:1892:18) at config.init.then (/home/batman/Projects/finball/finball-server/finball-parse-server/app/routes/general/ufm-message/index.js:11:17) at tryCatcher (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/fwsp-config/node_modules/bluebird/js/release/util.js:16:23) at Promise._settlePromiseFromHandler (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/fwsp-config/node_modules/bluebird/js/release/promise.js:512:31) at Promise._settlePromise (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/fwsp-config/node_modules/bluebird/js/release/promise.js:569:18) at Promise._settlePromise0 (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/fwsp-config/node_modules/bluebird/js/release/promise.js:614:10) at Promise._settlePromises (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/fwsp-config/node_modules/bluebird/js/release/promise.js:693:18) at Async._drainQueue (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/fwsp-config/node_modules/bluebird/js/release/async.js:133:16) at Async._drainQueues (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/fwsp-config/node_modules/bluebird/js/release/async.js:143:10) at Immediate.Async.drainQueues (/home/batman/Projects/finball/finball-server/finball-parse-server/node_modules/fwsp-config/node_modules/bluebird/js/release/async.js:17:14) at runCallback (timers.js:789:20) at tryOnImmediate (timers.js:751:5) at processImmediate [as _immediateCallback] (timers.js:722:5) i dont know how to proceed from here.

@cjus yes, i can use normal api request from non hydra app. but i chose random ports for microservices, so i need to know the port number assigned for that particular service.

Thanks.

[cjus]

@emjimadhu serverName cannot be blank.

[emjimadhu]

@cjus hey thank you for the reply. the server i am communicating from is not a service. just like it said in the below image, i made it blank. or am i understood wrong.

if i am wrong, what i have to do next? my scenario is i have a server and i want to communicate with hydra microservice.

[cjus]

@emjimadhu I see. I also went back to take a closer look at your sample program above. So you're initializing hydra in an express route? and trying to use the hydra. findService call to locate the firebase-service?

I recommend initializing hydra in your app initialization (main js file) and then importing hydra in your route file using:

const hydra = require('hydra');

Then later you can call hydra.findService('firebase-service')

I'll write a small test program to ensure this still works and I'll share that with you.

[cjus]

@emjimadhu So there is an issue with the documentation or perhaps I'll fix in an updated hydra release. serviceName is required and can't currently be blank. So here is a sample config.json file which does contain a serviceName.

{
  "hydra": {
    "serviceName": "caller",
    "serviceDescription": "",
    "serviceIP": "",
    "servicePort": 0,
    "serviceType": "",
    "redis": {
      "url": "redis://localhost:6379/15"
    }
  }
}

This Sample program shows a basic express app which loads hydra and attempts to locate information about hydra-routers which may be present. In your case that would be your firebase-service. In your earlier example you used the hydra.findService() call. But I think you probably need to use the hydra.getServicePresence() call which returns an array of all present service instances along with ip and port addresses. At the end of this post I shared the output of the program below.

const express = require('express');
const app = express();
const hydra = require('hydra');
const config = require('./config.json');

app.get('/', (req, res) => res.send('Hello World!'));
app.listen(3000, () => console.log('Example app listening on port 3000!'));

hydra.init(config)
  .then(() => {
    console.log('hydra initiated');
    return hydra.getServicePresence('hydra-router');
  })
  .then((service) => {
    console.log(service);
  })
  .catch((error) => {
    console.log(error)
  });

Output:

Array(1) [Object]
index.js:15
length:1
__proto__:Array(0) [, …]
0:Object {serviceName: "hydra-router", serviceDescription: "Service Router", version: "1.6.0", …}
  hostName:"AdministorsMBP2.fios-router.home"
  instanceID:"46bb1d0037264eb0898adde39cdd257e"
  ip:"192.168.1.221"
  port:1552
  processID:10750
  serviceDescription:"Service Router"
  serviceName:"hydra-router"
  updatedOn:"2018-02-19T03:55:52.114Z"
  updatedOnTS:1519012552114
  version:"1.6.0"
__proto__:Object {constructor: , __defineGetter__: , __defineSetter__: , …}

[emjimadhu]

@cjus Thank you so much. It worked.

[cjus]

You're welcome! I'm closing out this issue.