Simple REST server tutorial

Dependencies

pip3 install pillow jsonpickle

Overview

This is a simple example of a REST server using both GET and POST queries written using the Flask package. This is not intended to be an example of good programming practice or secure coding examples.

Sample Queries

Simple GET

 curl --verbose http://127.0.0.1:5000/api/add/10/20
*   Trying 127.0.0.1:5000...
* Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
> GET /api/add/10/20 HTTP/1.1
> Host: 127.0.0.1:5000
> User-Agent: curl/7.71.1
> Accept: */*
>
* Mark bundle as not supporting multiuse
* HTTP 1.0, assume close after body
< HTTP/1.0 200 OK
< Content-Type: application/json
< Content-Length: 13
< Server: Werkzeug/1.0.1 Python/3.8.5
< Date: Tue, 21 Sep 2021 17:39:02 GMT
<
* Closing connection 0
{"sum": "30"}

Simple POST

curl --verbose -d '{ "a" : 200, "b" : 100}' -H 'Content-Type: application/json' http://127.0.0.1:5000/api/sub
*   Trying 127.0.0.1:5000...
* Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
> POST /api/sub HTTP/1.1
> Host: 127.0.0.1:5000
> User-Agent: curl/7.71.1
> Accept: */*
> Content-Type: application/json
> Content-Length: 23
>
* upload completely sent off: 23 out of 23 bytes
* Mark bundle as not supporting multiuse
* HTTP 1.0, assume close after body
< HTTP/1.0 200 OK
< Content-Type: application/json
< Content-Length: 21
< Server: Werkzeug/1.0.1 Python/3.8.5
< Date: Tue, 21 Sep 2021 17:39:44 GMT
<
* Closing connection 0
{"difference": "100"}

POST with binary data

curl -v --data-binary @cu-in-snow.jpg -H 'Content-Type: image/png' http://127.0.0.1:5000/api/image
*   Trying 127.0.0.1:5000...
* Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
> POST /api/image HTTP/1.1
> Host: 127.0.0.1:5000
> User-Agent: curl/7.71.1
> Accept: */*
> Content-Type: image/png
> Content-Length: 515000
>
* We are completely uploaded and fine
* Mark bundle as not supporting multiuse
* HTTP 1.0, assume close after body
< HTTP/1.0 200 OK
< Content-Type: application/json
< Content-Length: 30
< Server: Werkzeug/1.0.1 Python/3.8.5
< Date: Tue, 21 Sep 2021 17:40:25 GMT
<
* Closing connection 0
{"width": 1613, "height": 856}