Forward Proxy Advanced

The Forward Proxy plugin allows Kong to connect to intermediary transparent HTTP proxies, instead of directly to the upstream_url, when forwarding requests upstream. This is useful in environments where Kong sits in an organization’s internal network, the upstream API is available via the public internet, and the organization proxies all outbound traffic through a forward proxy server.

Terminology

• plugin: a plugin executing actions inside Kong before or after a request has been proxied to the upstream API.
• Service: the Kong entity representing an external upstream API or microservice.
• Route: the Kong entity representing a way to map downstream requests to upstream services.
• Consumer: the Kong entity representing a developer or machine using the API. When using Kong, a Consumer only communicates with Kong which proxies every call to the said upstream API.
• Credential: a unique string associated with a Consumer, also referred to as an API key.
• upstream service: this refers to your own API/service sitting behind Kong, to which client requests are forwarded.
• API: a legacy entity used to represent your upstream services. Deprecated in favor of Services since CE 0.13.0 and EE 0.32.

Configuration

Enabling the plugin on a Service

With a database

Configure this plugin on a Service by making the following request:

$ curl -X POST http://kong:8001/services/{service}/plugins \
    --data "name=forward-proxy" 

Without a database

Configure this plugin on a Service by adding this section do your declarative configuration file:

plugins:
- name: forward-proxy
  service: {service}
  config: 

In both cases, {service} is the id or name of the Service that this plugin configuration will target.

Enabling the plugin on a Route

With a database

Configure this plugin on a Route with:

$ curl -X POST http://kong:8001/routes/{route}/plugins \
    --data "name=forward-proxy" 

Without a database

Configure this plugin on a Route by adding this section do your declarative configuration file:

plugins:
- name: forward-proxy
  route: {route}
  config: 

In both cases, {route} is the id or name of the Route that this plugin configuration will target.

Enabling the plugin on a Consumer

With a database

You can use the http://localhost:8001/plugins endpoint to enable this plugin on specific Consumers:

$ curl -X POST http://kong:8001/consumers/{consumer}/plugins \
    --data "name=forward-proxy" \
    

Without a database

Configure this plugin on a Consumer by adding this section do your declarative configuration file:

plugins:
- name: forward-proxy
  consumer: {consumer}
  config: 

In both cases, {consumer} is the id or username of the Consumer that this plugin configuration will target.

You can combine consumer_id and service_id

in the same request, to furthermore narrow the scope of the plugin.

Enabling the plugin on an API

If you are using an older version of Kong with the legacy API entity (deprecated in favor of Services since CE 0.13.0 and EE 0.32.), you can configure this plugin on top of such an API by making the following request:

$ curl -X POST http://kong:8001/apis/{api}/plugins \
    --data "name=forward-proxy" 

• api: either id or name of the API that this plugin configuration will target.

Global plugins

• Using a database, all plugins can be configured using the http://kong:8001/plugins/ endpoint.
• Without a database, all plugins can be configured via the plugins: entry on the declarative configuration file.

A plugin which is not associated to any Service, Route or Consumer (or API, if you are using an older version of Kong) is considered "global", and will be run on every request. Read the Plugin Reference and the Plugin Precedence sections for more information.

Parameters

Here's a list of all the parameters which can be used in this plugin's configuration:

Notes

The plugin attempts to transparently replace upstream connections made by Kong core, sending the request instead to an intermediary forward proxy. Currently only transparent HTTP proxies are supported; TLS connections (via CONNECT) are not yet supported.