KrakenD Playground

The KrakenD Playground is a demonstration environment that puts together the necessary pieces to get you started with our API Gateway, using example use-cases.

As KrakenD is an API gateway, we have added surrounding services:

Internal and third-party services that feed the gateway
Authentication/authorization examples, including JWT token-based authentication with Auth0 integration, a JWT token revoker, API-Key-based authentication, and basic authentication.
Integrations with Grafana+Influx (metrics), ELK (log storing and visualization), Jaeger (tracing), and RabbitMQ (for async agents).

Demo video

Click to play on Youtube (with subtitles)

Services

The docker-compose.yml includes the following services:

The API Gateway!

On port 8080, you have an instance of KrakenD Community Edition with several endpoints. Its configuration is available at config/krakend/krakend.json, including descriptive @comments for each endpoint.

Fake API backend (Upstream)

On port 8000, you have a simple fake API that provides raw data to the gateway. You can add or remove data by adding XML, JSON, or RSS files in the data folder.

It runs in http://localhost:8000

Metrics, logs & tracing

KrakenD can export telemetry to several services; this demonstration has a few examples. After starting the service and calling some endpoints, you will see the activity in Jaeger, Grafana, and Kibana.

Metrics	Logging	Tracing
Grafana shows the metrics stored by KrakenD on InfluxDB (credentials: admin/admin)	Kibana shows the logs registered by Logstash and persisted in Elasticsearch	Jaeger shows the traces of the activity between the client and your end services, including times of hops.
URL: http://localhost:4000	URL: http://localhost:5601	URL: http://localhost:16686

NOTE: To import a Kibana dashboard with some valuable metrics, run in the console the following command once all has started:

    $ make elastic

Web client

This consumer of the API gateway is a simple Express JS application that interacts with KrakenD to fetch the data. All code is under images/spa-auth-web/.

The client is a Single Page Application using Auth0 to generate JWT tokens.

You don't need to install any npm locally; the docker image will download and install the dependencies in the container.

Visit http://localhost:3000

The async agent

A RabbitMQ instance is ready to accept AMQP messages to be delivered to the gateway.

You can insert messages in the krakend queue at http://localhost:15672/#/queues/%2F/krakend (credentials: guest/guest) and see how the async agent picks them and delivers them.

The JWT revoker

A simple implementation of a JWT revoker using the KrakenD remote bloomfilter client.

More information about JWT revoking is available at https://www.krakend.io/docs/authorization/revoking-tokens/

It runs on http://localhost:9000

Start the service

Only if you want to try the Auth0 integration...

Create a new SPA application in Auth0 and fill the autogenerated values they give you under images/spa-auth-web/auth0-variables.js

var AUTH0_CLIENT_ID='AUTH0_CLIENT_ID';
var AUTH0_DOMAIN='AUTH0_DOMAIN';
var AUTH0_AUDIENCE = 'AUTH0_AUDIENCE';

You must do this before starting the docker-compose. If you have started docker-compose before setting these variables, you must build the image again with docker compose build web.

Running the playground

To start the stack included in docker-compose

    $ make start

To follow the KrakenD logs after the complete stack is up & running

    $ make logs

To shut down the complete stack, removing all the volumes

    $ make stop

Play!

Fire up your browser, curl, postman, httpie, or anything else you like to interact with any published services.

Fake API: http://localhost:8000
KrakenD API Gateway: http://localhost:8080
Jaeger (tracing): http://localhost:16686
Kibana (logs): http://localhost:5601
Grafana (metrics): http://localhost:4000
Sample SPA for auth: http://localhost:3000
JWT revoker: http://localhost:9000

When you change the krakend.json, the changes are applied automatically.

💡 Bonus track - Flexible configuration

💡 Bonus track - Flexible configuration
We've added an example of flexible configuration, so you can view how it works in practice. Apart from the default config file, `krakend.json`, you will find a `krakend-flexible-config.tmpl` that includes some code snippets, invokes a template using variables, and show some basic logic (iterations & conditions). When working with the flexible configuration, you can optionally ask KrakenD to save the "compiled" output to a file. We've added a command `make compile-flexible-config` so you can see quickly and easily how KrakenD builds the final configuration file based on the existing templates. Internally KrakenD's flexible configuration uses Golang templating syntax.

We've added an example of flexible configuration, so you can view how it works in practice.

Apart from the default config file, krakend.json, you will find a krakend-flexible-config.tmpl that includes some code snippets, invokes a template using variables, and show some basic logic (iterations & conditions).

When working with the flexible configuration, you can optionally ask KrakenD to save the "compiled" output to a file. We've added a command make compile-flexible-config so you can see quickly and easily how KrakenD builds the final configuration file based on the existing templates.

Internally KrakenD's flexible configuration uses Golang templating syntax.

Editing the API Gateway endpoints

To add or remove endpoints, edit the file krakend/krakend.json. The easiest way to do it is by dragging this file to the KrakenD Designer and downloading the edited file. If you move the downloaded file to krakend/krakend.json the server will apply the changes automatically.

The following endpoints are worth noticing:

Feature	Endpoint	Description
Simple request	`/public`	A simple request calling an internal service and returning a JSON response
Data aggregation and manipulation	`/git/{user}`	Aggregating multiple calls concurrently and manipulating some data from GitHub API
GraphQL to REST transformation	`/starwars_films/{movie_id}`	Transforming a GraphQL query into a regular REST API endpoint
Caching backend responses	`/market/cached`	Caching a backend response (based on cache headers provided by the backend)
Concurrent requests	`/market/concurrent`	Using concurrent requests to gather data from Coingecko API
Sequential calls	`/sequential`	Using sequential proxy to build a pipe of sequential calls, using values from 1st call response into 2nd call request
An aggregated requests with a failing backend	`/fail`	An example on how the `X-KrakenD-complete` header works when a backend fails on an aggregated response
JWT based Authentication	`/private/auth0`	Protects and endpoint validating JWT tokens issued by Auth0

You will find more examples with comments in config/krakend/krakend.json

Contribute!

Everyone can get started with KrakenD at this repository.

Try it out! If it doesn't help you, or you think you can add additional endpoints or middleware integrations, please open a pull request! (We may be too used to KrakenD and don't recognize what a starter demo should include.)

Thanks!

If you have any questions or doubts, you can find our support resources at https://www.krakend.io/support/

Interested in a demo or a trial license of KrakenD Enterprise? Write us »

Note: if you're looking for the KrakenD Enterprise Edition Playground, you'll find it here: https://github.com/krakendio/playground-enterprise