Add and test rate limiting field to Proxy backend collection

[bajiat]

(Description updated due to multiproxy development) Rate limiting setting is one of the key settings API owner needs in order to control the traffic to the API. Make sure it works correctly in Apinf - to the extent that API Umbrella supports it. Add the field to the new Proxy Backends collection

Potential user stories

As an API owner
I want to limit the usage of my API for a
particular API consumer

As an API owner
I want to be able to set and change a default rate limit
for my API for a certain period of time

Definition of done

• Make sure the rate limiting options get stored in the Proxy Backends collection
• Make sure the options are aligned with Api Umbrella
• Make sure the selected option is passed correctly to the Admin REST API
  • Optional idea: start by testing passing the setting with a REST call only (e.g. Postman)
• Make sure it gets stored (and changed when updated) properly in API Umbrella
• Make sure there is a setting for rate limiting in Proxy tab in API profile

Wireframe

Scenario 1: API owner sets default request rate of API-Umbrella Proxy

Scenario 2: API Owner customizes Request Rate Limits based on API key or specific IP Address. There can be multiple customizations and may vary by durations (seconds/minutes/hours etc.). Owner can select a customized settings as primary.

Scenario 3: API owner sets unlimited API calls

[55]

@jykae, will you take this task? We can work together on this.

[jykae]

@NNN yes, I assign myself.

[jykae]

Depends #622

[jykae]

Rate limits in Umbrella: http://api-umbrella.readthedocs.io/en/latest/api-consumer/rate-limits.html

Default limit is 1,000 requests per hour