App to handle inbound and outbound SMS
This is a simple SMS app that exposes the following 2 APIs that accepts JSON data as input.

• This app is written in Python using Flask web framework.
• Caching and Ratelimiting is implemented by maintaining required information in Redis.
• User data (credentials) are stored in SQLite.

Install all required Python packages using requirements.txt

virtualenv env
source env/bin/activate
pip install -r requirements.txt

Install and run Redis server by following these steps:

https://redis.io/topics/quickstart

OR
https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-redis-on-ubuntu-16-04
Note that, default port for Redis is 6379. If your Redis server is running at different port, change it in config.py.

This is a Python Flask server. Use script run.py to run the server locally.

python run.py

You can access the server at http://127.0.0.1:5000/

Test user is already populated in sqlite database. Credentials user:secret can be used for Basic authentication.

Run the unit tests using following script

python tests/unittests.py
python tests/integration.py

URL: /inbound/sms/
Authentication: Basic
Method: POST

• from (min length 6, max length 16)
• to (min length 6, max length 16)
• text (min length 1, max length 120)

• Input parameters should be valid
• When text is STOP or STOP\n or STOP\r or STOP\r\n, The ‘from’ and ‘to’ pair must be cached with an expiry of 4 hours.

If required parameter is missing:
{"message": "", "error": "<parameter_name> is missing"}

If parameter is invalid:
{"message": "", "error": "<parameter_name> is invalid"}

Any unexpected error:
{"message": "", "error": "unknown failure"}

If all parameters are valid:
{"message": "inbound sms is ok", "error": ""}

URL: /outbound/sms/
Authentication: Basic
Method: POST

Parameter required example

• from (min length 6, max length 16)
• to (min length 6, max length 16)
• text (min length 1, max length 120)

• Input parameters should be valid
• If the pair of ‘from’ and ‘to’ matches the cached pair(STOP), return an error response with appropriate HTTP status code (see Output JSON response below)
• Do not allow more than 50 API requests using the same ‘from’ number in 1 hour. Return an error response with appropriate HTTP status code in case the limit has been reached (see Output JSON response below)

If required parameter is missing:
{"message": "", "error": "<parameter_name> is missing"}

If parameter is invalid:
{"message": "", "error": "<parameter_name> is invalid"}

If the pair ‘to’ and ‘from’ matches the cached pair:
{"message": "", "error": "sms from <from> and to <to> blocked by STOP request"}

If 50 requests limit reached in last 1 hour with same ‘from’ parameter:
{"message": "", "error": "limit reached for from <from>"}

Any unexpected error:
{"message": "", "error": "unknown failure"}

If all parameters are valid:
{"message": "inbound sms is ok", "error": ""}