Web servers for the Internet of Things

We servers for the Internet of things

1. Web servers for the Internet of Things Summer School

2. Outline Web server HTTP Gadgets IoT Webserver Web templates Web services Web socket Questions 2

3. Web server 3

4. What is a web server Software that implements HTTP/HTTPS Mainframes Computers Gadgets 4

5. Gadgets?! 5

6. What HTTP? Widely used Easy to implement Text based HTML Simple and flexible UI JavaScript runs in almost any browser Replace displays 6

7. UI Gadgets prefer HTML UI Accessible from the tablet Wireless “display” Web language Gadgets are using less displays Expensive Fixed Special software 7

8. HTTP 8

9. HTTP 9 Image from https ://www3.ntu.edu.sg/home/ ehchua /programming/ webprogramming / HTTP_Basics.html

10. HTTP Request Headers Method URL Query String Upload body Response Status Headers Data 10

11. Query http://address[:port] URL?querystring http://wyliodrin.cs.pub.ro/ projects?show =true Address? Port? URL? q uerystring ? 11

12. Query http://address[:port] URL?querystring http://wyliodrin.cs.pub.ro/ projects?show =true Address? w yliodrin.cs.pub.ro Port? 80 URL? /projects querystring ? show=true 12

13. Methods GET Request objects without sending data POST Modify objects with data that you are sending PUT Create new objects with data that your are sending DELETE Delete objects without sending data 13

14. HTTP 14 Image from https ://www3.ntu.edu.sg/home/ ehchua /programming/ webprogramming / HTTP_Basics.html

15. Gadgets 15

16. Webserver for the gadgets 16

17. Web Web request Starts a webserver Sets up static folder Stores Html Javascript Css http:// address:port /static/ index.html 17

18. Web Web request Route Method Port Message { payload : query string / upload data req : request res: response next: } 18

19. Web response 19 Web response Input from a web request Sends the payload Redirect http:// address:port / redirects to http:// address:port /static/ index.html

20. Run the server Get the IP of the board Shell ifconfig In the same network http://172.17.0.82:5000/ 20

21. IoT Server 21

22. IoT Server Server with public IP address A gadget without pin access Good for web server Web pages API 22

23. IoT Server 23

24. Web templates 24

25. Web template Web template Loads a templates Fills it with variables From value From payload Sends it 25

26. Web template 26 Values are available Payload variables are available

27. Web template 27 Value is refreshed only on a page reload

28. Web service 28

29. Web service is API Expose functions for apps Mobile Applications Refresh the value without reloading the page Use multiple UI 29 Image from http :// blogs.msdn.com /b/ martinkearn /archive/2015/01/05/introduction-to-rest-and-net-web- api.aspx

30. Web response 30 Web response Input from a web request Sends the payload Redirect

31. Web response 31 /sensor returns { “sensor”: “0” }

32. JQuery API 32

33. Web socket 33

34. Websocket Allows asynchronous communication with the server Like a socket Uses HTTP or HTTPS Problems with proxies Socket.IO Has a solution with HTTP or HTTPS if the websocket is unavailable 34

35. Websocket 35 Image from https :// warmcat.com / libwebsockets /2010/11/01/libwebsockets-html5-websocket-server-library-in-c.html

36. Web starter app Streams Web starter app Angular JS 36

37. Angular JS static/ w eb.html 37

38. Javascript 38

39. Questions? 39