adding pagination support to the Consumers resource

[ErwannRobin]

Useful when you have more than 100 consumers on Kong

[PGBI]

Ah, I'm surprised this didn't come up sooner. Looks like you're the only one with more than 100 consumers! Thanks for this PR.

Would you mind completing it to also handle pagination for APIs and Plugins resources?

[ErwannRobin]

@PGBI : done for the APIs and Plugins resources, but not yet for '/apis/:api_id/plugins' and '/consumers/:consumer_id/plugins' because it seems more tricky.

[PGBI]

@diwann So I checked out the code to test it locally, and found these issues:

• being on http://localhost:8080/#/consumers, with around 4000 consumers, when I click "Go to next Page", I'm redirected to http://localhost:8080/#/consumers?offset=undefined&size=, which doesn't load the next page. I'm using Chrome.
• The shortcut "Check the Plugins for this Consumer" on the consumer edit form is a good idea. However, it's also displayed on the consumer creation form (http://localhost:8080/#/consumers/add) which doesn't make sense in that context.
• I don't understand the "Gelato Links for consumers" on the config page. What is that?

Regarding '/apis/:api_id/plugins' and '/consumers/:consumer_id/plugins', if paginating them is tricky, I guess we can leave them for now. Being able to paginate consumers, apis and plugins will already be a great improvement!

[ErwannRobin]

1. What do you get on: http://localhost:8001/consumers ?
   Does it work on: http://localhost:8080/#/apis?size=1 ?
2. Fixed
3. This will conditionally create shortcuts links to the profile page of the same consumer on the gelato dashboard (like https://gelato.io/app/developers/582187067111376096). Because I am constantly switching to it and copy-pasting the consumer id is not ideal
   cf:
   

[PGBI]

When I browse http://localhost:8080/#/consumers I get this:

Then, when clicking on "Go To next page", the browser location is set to http://localhost:8080/#/consumers?offset=undefined&size= and I'm still seing page 1.

[ErwannRobin]

no, I really meant on "http://localhost:8001/consumers", assuming your Kong node is on localhost?

on my side, I have:

[PGBI]

My bad, didn't read properly your question. I'm getting this:

{
  "next": "http://localhost:8001/consumers?size=100&offset=ABAjkv8D155L5LLViAu8HE4OAAsACHVzZXJuYW1lAH%2F%2F%2F5s%3D",
  "data": [
    {
      "custom_id": "3130",
      "username": "App-3130",
      "created_at": 1469234887000,
      "id": "a0754d16-6108-4e8a-9688-5151d6647062"
    },
    { 
      ...
    }
]

This is with Kong 0.6.1

[ErwannRobin]

Ok, fixed. it seems that Kong 0.6.1 didn't had the "offset" parameter.
Also, I finally tackled the pagination of '/apis/:api_id/plugins' and '/consumers/:consumer_id/plugins'

and Happy New Year!

[PGBI]

@diwann Parfait, c'est mergé. Merci pour ta contribution !