Kong Middleman advanced

A Kong plugin that enables an extra HTTP POST requests before proxying the original.

based on https://github.com/pantsel/kong-middleman-plugin and https://github.com/mdemou/kong-middleman

Description

In some cases, you may need to validate a request to a separate server or service using custom logic before Kong proxies it to your API. Middleman enables you to do that by allowing you to make an extra HTTP requests before calling an API endpoint.

Change from the original plugin

list of change :

• Update for kong v2
• move json.lua to https://github.com/rxi/json.lua
• Update schema for v2
  • add config for include certificate (default false)
  • add config for include credential (default false)
  • add config for include route (default false)
  • add config for include consumer (default false)
• change payload :
  • add certificate (resty_kong_tls.get_full_client_certificate_chain())
  • add credential (kong.client.get_credential())
  • add route (kong.router.get_route() and kong.router.get_service())
  • add consumer (kong.client.get_consumer())
  • rename uri_args to params
  • rename body data to body
  • no json.encode if headers["content-type"] == 'application/json'
  • move body, headers and params in request field

payload :

local payload = {
    ['certificate'] = certificate,
    ['consumer'] = consumer,
    ['credential'] = credential,
    ['kong_routing'] = kong_routing,
    ['request'] = {
      ['headers'] = headers,
      ['params'] = params,
      ['body'] = json_body,
    }
  }

Installation

WIP

Configuration

You can add the plugin on top of an API by executing the following request on your Kong server:

$ http POST :8001/services/{api}/plugins name=middleman-advanced config:='{ "services": [{"url": "http://myserver.io/validate", "response": "table", "timeout": 10000, "keepalive": 60000}]}'

form parameter	default	description
name		The name of the plugin to use, in this case: middleman
config.services required		The list of services witch the plugin make a JSON POST

Service config

form parameter	default	description
url required		The URL to which the plugin will make a JSON POST request before proxying the original request.
response required	table	The type of response the middleman service is going to respond with
timeout	10000	Timeout (miliseconds) for the request to the URL specified above. Default value is 10000.
keepalive	60000	Keepalive time (miliseconds) for the request to the URL specified above. Default value is 60000.
include_cert	false	Include the original certificate in JSON POST
include_credential	false	Include the credential in JSON POST
include_consumer	false	Include the consumer in JSON POST
include_route	false	Include the route in JSON POST

Middleman will execute a JSON POST request to the specified url with the following body:

JSON POST

Attribute	Description
certificate	The certificate of the original request if include_credential see resty_kong_tls.get_full_client_certificate_chain()
consumer	The consumer of the original request see kong.client.get_consumer()
credential	The consumer of the original request see kong.client.get_credential()
kong_routing	The kong_routing of the original request see kong.router.get_route() and kong.router.get_service()
request	The request of the original request see the next table : request

Request

Attribute	Description
body	The body of the original request
params	The url arguments of the original request
headers	The headers of the original request

In the scope of your own endpoint, you may validate any of these attributes and accept or reject the request according to your needs. If an HTTP response code of 299 or less is returned, the request is accepted. Any response code above 299 will cause the request to be rejected.

Author

David TOUZET

License

The MIT License (MIT)
=====================

Copyright (c) 2020 David TOUZET

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.