Reedelk Transformer plugin

Community Plugin: This plugin is developed, tested, and maintained by a third-party contributor.

The Reedelk Transformer plugin transforms the upstream request body or downstream response body by invoking a Reedelk REST flow before hitting the upstream server, or before sending the downstream response back to the client. The plugin can apply both upstream and downstream transformations in the same flow.

Installation

Prerequisites

To use the Reedelk plugin for Kong, you must first install the Reedelk IntelliJ IDEA flow designer plugin using either of the following options:

IntelliJ Marketplace: Go to IntelliJ Preferences > Plugin > Marketplace, search for Reedelk, install the plugin, and restart IntelliJ.
Manual install: From IntelliJ Preferences > Plugin > Settings icon > Install Plugin From Disk, and restart IntelliJ.

Install the Reedelk Transformer plugin

Clone the kong-plugin-reedelk-transformer:

 $ git clone https://github.com/reedelk/kong-plugin-reedelk-transformer.git
 $ cd kong-plugin-reedelk-transformer

Install the module kong-plugin-reedelk-transformer:

$ luarocks install kong-plugin-reedelk-transformer-0.1.0-1.all.rock

Add the custom plugin to kong.conf:
```
plugins = ...,reedelk-transformer
```
Restart Kong.
```
$ kong restart
```

Build and package the plugin

Install the LuaRocks package manager.

Clone the kong-plugin-reedelk-transformer:

 $ git clone https://github.com/reedelk/kong-plugin-reedelk-transformer.git
 $ cd kong-plugin-reedelk-transformer

Build the plugin locally (based on the .rockspec in the current directory):
```
$ luarocks make
```

Package the plugin:

$ luarocks pack kong-plugin-reedelk-transformer 0.1.0-1

Hello World Example

This example uses a prepackaged kong-reedelk Docker image with Kong and the reedelk-transformer plugin already installed. You can find the kong-reedelk Docker images on Docker Hub.

The kong-reedelk image is preconfigured to use the following kong.yml file, which defines an upstream service mapped on Route http://localhost:8000/transform and invokes a downstream transformer with the reedelk-transformer plugin. The configured downstream transformer integration flow URL is:

http://host.docker.internal:8282/api/message

Prerequisites

Docker must be installed.
IntelliJ IDEA IDE must be installed.
Reedelk IntelliJ Flow Designer Plugin must be installed on your IntelliJ distribution.

Run the example

In the following steps, you run the kong-reedelk docker image, and then create a new Reedelk project that contains the integration flow invoked by the downstream transformer.

Run the kong-reedelk Docker image:

$ docker run -d --name kong-reedelk-transformer-plugin \
         -p 8000:8000 \
         -p 8443:8443 \
         -p 127.0.0.1:8001:8001 \
         -p 127.0.0.1:8444:8444 \
         reedelk/kong-reedelk-transformer-plugin:latest

Make sure that Kong is up and running correctly with the reedelk-transformer plugin installed:
```
$ curl http://localhost:8001/plugins
```
Open IntelliJ and create a new Reedelk project. The newly created project contains a POST Hello World flow to use as integration flow invoked by the downstream transformer.
Start the new Reedelk project by clicking Play next to the Reedelk Runtime run configuration in IntelliJ.
Call the Kong Route with the following URL:
```
$ http://localhost:8000/transform
```
The result should be:

Hello World John

For more information about this example, including testing the IntelliJ Flow Designer Plugin workflow with Insomnia, see:

Reedelk Getting Started documentation.
Reedelk plugin documentation on GitHub.
Kong Reedelk Transformer Plugin Demo video on Youtube.

Configuration Reference

This plugin is not compatible with DB-less mode.

Enable the plugin on a service

Admin API

Kubernetes

Declarative (YAML)

For example, configure this plugin on a service by making the following request:

curl -X POST http://{HOST}:8001/services/{SERVICE}/plugins \
    --data "name=reedelk-transformer"  \
    --data "config.upstream_transformer_url=http://myhost/upstream/transform" \
    --data "config.downstream_transformer_url=http://myhost/downstream/transform"

SERVICE is the id or name of the service that this plugin configuration will target.

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <reedelk-transformer-example>
config: 
  upstream_transformer_url: http://myhost/upstream/transform
  downstream_transformer_url: http://myhost/downstream/transform
plugin: reedelk-transformer

Next, apply the KongPlugin resource to a Service by annotating the Service as follows:

apiVersion: v1
kind: Service
metadata:
  name: {SERVICE}
  labels:
    app: {SERVICE}
  annotations:
    konghq.com/plugins: <reedelk-transformer-example>
spec:
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
    name: {SERVICE}
  selector:
    app: {SERVICE}

{SERVICE} is the id or name of the service that this plugin configuration will target.

Note: The KongPlugin resource only needs to be defined once and can be applied to any service, consumer, or route in the namespace. If you want the plugin to be available cluster-wide, create the resource as a KongClusterPlugin instead of KongPlugin.

For example, configure this plugin on a service by adding this section to your declarative configuration file:

plugins:
- name: reedelk-transformer
  service: {SERVICE}
  config: 
    upstream_transformer_url: http://myhost/upstream/transform
    downstream_transformer_url: http://myhost/downstream/transform

SERVICE is the id or name of the service that this plugin configuration will target.

Enable the plugin on a route

Admin API

Kubernetes

Declarative (YAML)

For example, configure this plugin on a route with:

$ curl -X POST http://{HOST}:8001/routes/{ROUTE}/plugins \
    --data "name=reedelk-transformer"  \
    --data "config.upstream_transformer_url=http://myhost/upstream/transform" \
    --data "config.downstream_transformer_url=http://myhost/downstream/transform"

ROUTE is the id or name of the route that this plugin configuration will target.

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <reedelk-transformer-example>
config: 
  upstream_transformer_url: http://myhost/upstream/transform
  downstream_transformer_url: http://myhost/downstream/transform
plugin: reedelk-transformer

Then, apply it to an ingress (Route or Routes) by annotating the ingress as follows:

apiVersion: networking/v1beta1
kind: Ingress
metadata:
  name: {ROUTE}
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/plugins: <reedelk-transformer-example>
spec:
  rules:
  - host: examplehostname.com
    http:
      paths:
      - path: /bar
        backend:
          serviceName: echo
          servicePort: 80

ROUTE is the id or name of the route that this plugin configuration will target.

For example, configure this plugin on a route by adding this section to your declarative configuration file:

plugins:
- name: reedelk-transformer
  route: <route>
  config: 
    upstream_transformer_url: http://myhost/upstream/transform
    downstream_transformer_url: http://myhost/downstream/transform

ROUTE is the id or name of the route that this plugin configuration will target.

Enable the plugin globally

A plugin which is not associated to any service, route, or consumer is considered global, and will be run on every request. Read the Plugin Reference and the Plugin Precedence sections for more information.

Admin API

Kubernetes

Declarative (YAML)

For example, configure this plugin globally with:

$ curl -X POST http://{HOST}:8001/plugins/ \
    --data "name=reedelk-transformer"  \
    --data "config.upstream_transformer_url=http://myhost/upstream/transform" \
    --data "config.downstream_transformer_url=http://myhost/downstream/transform"

Create a KongClusterPlugin resource and label it as global:

apiVersion: configuration.konghq.com/v1
kind: KongClusterPlugin
metadata:
  name: <global-reedelk-transformer>
  annotations:
    kubernetes.io/ingress.class: kong
  labels:
    global: \"true\"
config: 
  upstream_transformer_url: http://myhost/upstream/transform
  downstream_transformer_url: http://myhost/downstream/transform
plugin: reedelk-transformer

For example, configure this plugin using the plugins: entry in the declarative configuration file:

plugins:
- name: reedelk-transformer
  config: 
    upstream_transformer_url: http://myhost/upstream/transform
    downstream_transformer_url: http://myhost/downstream/transform

Parameters

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

Form Parameter	Description
`name` required Type: string	The name of the plugin, in this case `reedelk-transformer`.
`service.id` Type: string	The ID of the Service the plugin targets.
`route.id` Type: string	The ID of the Route the plugin targets.
`enabled` required Type: boolean Default value: `true`	Whether this plugin will be applied.
`config.upstream_transformer_url` optional	The URL of the Reedelk REST flow endpoint to invoke for the upstream request transformation.
`config.downstream_transformer_url` optional	The URL of the Reedelk REST flow endpoint to invoke for the downstream request transformation.

The upstream_transformer_url and downstream_transformer_url are the URLs of the Reedelk REST flow endpoint to invoke for the upstream/downstream request/response transformations; e.g., http://localhost:8888/apiabledev/transform.

About this Plugin
Made by	codecentric AG
Categories	Transformations
DB-less compatible?	Yes
Compatible protocols	`http` `https`
Support	github.com
Source	Code License (Apache-2.0)