short question : How can I host an MQTT server on my remote Ubuntu 16 server while at the same time hosting an HTTP server that will be using the MQTT data ?
true question : I want to build an IoT system that will be MONITORED and CONTROLLED by ESP32, which will SEND FEEDBACK and ACCEPT COMMANDS respectively from a remote server (maybe LAMP ?). I also want the user to log-in in a website hosted on this remote server, where s/he can monitor any sensor values or send commands (e.g. turning a led on or off).
So what's the way to go here?
I was adviced to go with MQTT but then the above problem arised.
what I've found : I 've found that using Mosquitto MQTT, I may be able to serve a website using websockets. But I prefer a more scalable HTTPS approach. That is, I intend to have a database linked with my site and running my PHP scripts.
I'm not that experienced, so please don't take anything for granted :)
MQTT uses TCP connection and follows publish/subscribe API model where as the web(http) follows Restful API model(Create,read,update,delete). If you want to stick with MQTT then you should use SAAS service like enterprise MQTT from HIVE which provide this integrability but will charge some fees and in return, they will provide you with an account and a dashboard for all your devices. Otherwise, you can try to make your own middleware which can integrate MQTT with web services .
Another thing I would recommend is CoAP which is also an M2M protocol but follows Restful API model and UDP connection. It has direct forward proxy to convert coap packets to https packets and vice versa.
In MQTT you have a central server(Broker) to which the nodes send their data and fetch their required data through topic filters.
In CoAP each device having some data to share becomes a server and the other device interested in it's data becomes a client and sends a GET request to the respective server to get its data. Similarly a PUT request along with a payload from a client would update the value at the server.
You really should not be looking to combine the MQTT broker with a HTTP server, especially if you intent the HTTP Server to actually be an application server (Running back end logic e.g. PHP). These are 2 totally separate systems. There is nothing to stop your application logic connecting to the broker as a client.
If you intend to use MQTT over WebSockets you can use something link nginx to proxy the WebSockets connection to the broker so it can sit behind the same logical HTTP/HTTPS address.
Related
I am doing an IOT platform for my final year project at university, the concept is to link an IoT device with the Platform using WebSockets. My Websocket is working very well and I can send message from server to client.
But I don't know how to connect two clients to send messages to others via websocket server.
I can send message between website and server and also between my esp8266 and server.
how can I connect my arduino to the website?
Thank you
A WebSocket is basically a persistent connection between a client and
server.
In order for devices to talk with each other they first need to pass
by the server.
The server simply redirects the messages to the client that needs to
receive it.
Generally you'd have the WebSocket server in your backend.
Your frontend will be a WebSocket client.
Your device will be another WebSocket client.
Help needed please
What's is the best WebSocket client library for a .net 4.5 on windows web application hosted on windows 2008 servers to connect to a remote server web socket.
The scenario is: our web application will use a web socket to connect to a server WebSocket on a third party infrastructure. Our client WebSocket will connect and send some commands and read the responses where we can identify the information needed. So there is no interaction from the user or browser its just in the code. e.g. user clicks a button and we go and get some data, and give a message dependant on the response.
so for example our client will connect to the third party socket and pass the users car registration number and send a tell me the car details and the server socket will return the data like: make, model, year etc... so we can then display that to the user.
Has anyone used this library with some good success? http://www.nuget.org/packages/WebSocket4Net
I'm hoping someone here can provide the best approach for doing this with some tried and tested solutions. I have been thinking about a web API that handles all the socket stuff in our client so i can call it and let it handle the close connection etc.
I need to develop an application which would run in a corporate network. The client should both receive commands (shutdown, restart, ...) and send info (something happened, ...) from/to the server. So, using a web interface, the network administrator would be able to see what clients are connected, send commands to them, and see real-time info coming from them. The client should be written in Delphi (normal VCL forms with Edits, etc.) and the server "preferably" in ASP.Net.
I researched a bit and I think WebSockets might be good to achieve this. I plan to use some WebSocket libraries for Delphi like this. I'm not sure what technology I should use for the server.
Please tell me if WebSockets is good for my requirements. Other solutions are welcome (maybe writing the server in Delphi?).
Web interfaces typically are HTML based views, and require a web HTTP server and a web browser (Chrome, Firefox, etc.). Delphi Web Socket client libraries however can only be used to talk with a Web Socket server from within a native Delphi application, for example a VCL GUI.
If you plan to write a VCL application (not web browser based), you have other transport protocol options besides Web Sockets, which are widely used in small and large systems:
MQTT (formerly Message Queue Telemetry Transport)
STOMP (Streaming Text Oriented Messaging Protocol)
AMQP (Advanced Message Queuing Protocol)
MSMQ (Microsoft Message Queuing)
As with WebSockets, these protocols offer asynchronous / bi-directional messaging. On the server side you can choose from many production quality implementations of these protocols (known as 'message brokers'), mostly free / open source. Similar to HTTP, message payload can be anything - text or binary data - and messages can use headers to provide application-defined metadata.
Your server-side application code can be written in Delphi, and is only another client of the message broker, communicating with the client applications over the message broker protocol. As soon as client and server are connected to the message broker, messages can flow in both directions.
Many advanced features are included in message brokers: if a client disconnects while the server is still sending messages, the message broker can store these messages and deliver them as soon as the client reconnects.
For most of these protocols I have seen client libraries or wrappers for Delphi / Object Pascal, free and open source or commercial.
I want my client program to communicate with a server without making the user add an exception to Windows Firewall in elevated mode. Is there a way to do this? HTTP? For instance, uTorrent and Google Chrome can both be installed by a regular (non-admin) user, and both programs network quite extensively - how do they do this? Am I missing something about how the firewall and/or ports works?
Yes there is a way. Assuming that your client program is the one running on the users machine and that your client program is the one initiating communication with the server then your client program generally would not need to require end user to open any exceptions in the windows firewall as long as you stick to using http over port 80. Http on port 80 is generally open for outbound traffic (initiated by the client) and therefor you could build your communication (and if needed your own protocol) on top of the http protocol. This is the typical scenario for webserver and webbrowsers (clients).
If you need the server to initiate the communication it becomes more complex and a lot of different approaches could be used. Choice of communication channels and structure should depend on factors like whether you would want to communicate to one client at a time or many (broadcast/multicast), do you need encryption, what are your needs for speed (throughput and latency), what kind of system are you trying to build and so on.
Many webapplications achieve an effect of a server initiated communication by using special techniques called polling, long polls, comet, websockets and so on. these work through http on top of tcp/ip on port 80. Other systems employs subscription mechanisms to be able to get notified through a third part if something new has happened. If you need server initiated communications please let me now and i will try to give a better explanation on the options.
i've been searching and trying for weeks now to find a solution to my issue that I can understand and easily implement but I had no joy. So i would be very grateful if someone could put me out of my misery.
I'm building an iphone app similar in functionality to apps like "Air Video" and "Air Playit". The app should communicate with a server running on a remote host. This server should be able to execute a command sent by the iphone to encode a video and stream it over http.
In my case, my iphone app sends commands to be executed on a remote host. the remote host is running a python socket server listening for example on port 3333.
On the iphone, i'm simply using
"CFStreamCreatePairWithSocketToHost", "CFWriteStreamOpen" and
"CFReadStreamOpen"
to connect, write and read data.
My remote host, successfully intercepts the commands and starts the encoding.
To serve the contents, I'm having to run a separate http server (i'm using Python simpleHTTPServer) which is listening on another port.
What I would like to do is use the same port for both system commands and http requests.
The apps I've mentioned above seem to do it that way and I've noticed they have their own build-in web server.
I'm sure I'm missing something but please bear with me this is my first attempt at building an app.
Encode your system commands into special HTTP requests. Decide which thing to do (execute command or serve the contents) based on HTTP request, not on the incoming port. If you need to use separate http servers (like you told), consider having a layer that receives everything from the devices and dispatches to other servers (or ports) based on the request.