Set Upstream Host - Kong plugin

Getting Started

This plugin can be used when request from the API clients has to be routed to different upstream nodes based on the node number for which data is requested. This plugins extracts the parameter from incoming request either from header, query, path or request body and forms the upstream host dynamically. This plugin supports forming upstream host from below parameters -

• From request header
• From query params
• From path params
• From json or form-urlencoded request body

Steps to use this plugin

Create a service

curl -i -X POST \
 --url http://localhost:8001/services/ \
 --data 'name=node-details' \
 --data 'url=https://nodenumber.org'

Create a route

curl -i -X POST \
 --url http://localhost:8001/services/node-details/routes \
 --data 'paths[]=/anything' \
 --data 'strip_path=false'

1) Add plugin to service - When node number is passed in request header

curl -i -X POST \
 --url http://localhost:8001/services/node-details/plugins/ \
 --data 'name=set-target-host' \
 --data "config.upstream_host=nodenumber.org" \
 --data "config.string_to_replace_from_host=nodenumber" \
 --data "config.header=node" 

Test API

curl -i 'http://localhost:8000/anything' --header 'node: httpbin'

Here plugin will read node header value and it will replace nodenumber string from hostname with this value. Final upstream hostname formed in this example will be httpbin.org

2) When node number is passed in query parameter

Update plugin -

curl -X PUT http://localhost:8001/services/node-details/plugins/{plugin_id} \
 --data 'name=set-target-host' \
 --data "config.upstream_host=nodenumber.org" \
 --data "config.string_to_replace_from_host=nodenumber" \
 --data "config.query_arg=node" 

Test API

curl -i 'http://localhost:8000/anything?node=httpbin'

3) When node number is passed in request body

Update plugin -

curl -i -X PUT http://localhost:8001/services/node-details/plugins/{plugin_id} \
 --data 'name=set-target-host' \
 --data "config.upstream_host=nodenumber.org" \
 --data "config.string_to_replace_from_host=nodenumber" \
 --data "config.body_param=node" 

Test API - When Content-Type is application/json

curl -i 'http://localhost:8000/anything' \
--header 'Content-Type: application/json' \
--data-raw '{
    "node": "httpbin"
}'

Test API - When Content-Type is application/x-www-form-urlencoded

curl -i 'http://localhost:8000/anything' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'node=httpbin'

4) When node number is passed in path parameter

Update plugin -

curl -i -X PUT http://localhost:8001/services/node-details/plugins/{plugin_id} \
 --data 'name=set-target-host' \
 --data "config.upstream_host=nodenumber.org" \
 --data "config.string_to_replace_from_host=nodenumber" \
 --data "config.path_index=2" 

Test API

curl -i 'http://localhost:8000/anything/httpbin'

Contributers

Name	Email Id
Anup Kumar Rai	[email protected]
Saravanan Periyasamy	[email protected]