/ Distributed Systems

A fast and distributed Microservice Abstraction Layer

A fast and distributed Microservice Abstraction Layer

Kong

Kong is a cloud-native, fast, scalable, and distributed Microservice Abstraction Layer (also known as an API Gateway, API Middleware or in some cases Service Mesh). Made available as an open-source project in 2015, its core values are high performance and extensibility.

Actively maintained, Kong is widely used in production at companies ranging from startups to Global 5000 as well as government organizations.

Why Kong?

If you are building for the web, mobile, or IoT (Internet of Things) you will
likely end up needing common functionality to run your actual software. Kong
can help by acting as a gateway (or a sidecar) for microservices requests while
providing load balancing, logging, authentication, rate-limiting,
transformations, and more through plugins.

kong

Features

  • Cloud-Native: Platform agnostic, Kong can run from bare metal to
    Kubernetes.
  • Dynamic Load Balancing: Load balance traffic across multiple upstream
    services.
  • Hash-based Load Balancing: Load balance with consistent hashing/sticky
    sessions.
  • Circuit-Breaker: Intelligent tracking of unhealthy upstream services.
  • Health Checks: Active and passive monitoring of your upstream services.
  • Service Discovery: Resolve SRV records in third-party DNS resolvers like
    Consul.
  • Serverless: Invoke and secure AWS Lambda or OpenWhisk functions directly
    from Kong.
  • WebSockets: Communicate to your upstream services via WebSockets.
  • OAuth2.0: Easily add OAuth2.0 authentication to your APIs.
  • Logging: Log requests and responses to your system over HTTP, TCP, UDP,
    or to disk.
  • Security: ACL, Bot detection, whitelist/blacklist IPs, etc...
  • Syslog: Logging to System log.
  • SSL: Setup a Specific SSL Certificate for an underlying service or API.
  • Monitoring: Live monitoring provides key load and performance server
    metrics.
  • Forward Proxy: Make Kong connect to intermediary transparent HTTP proxies.
  • Authentications: HMAC, JWT, Basic, and more.
  • Rate-limiting: Block and throttle requests based on many variables.
  • Transformations: Add, remove, or manipulate HTTP requests and responses.
  • Caching: Cache and serve responses at the proxy layer.
  • CLI: Control your Kong cluster from the command line.
  • REST API: Kong can be operated with its RESTful API for maximum
    flexibility.
  • Geo-Replicated: Configs are always up-to-date across different regions.
  • Failure Detection & Recovery: Kong is unaffected if one of your Cassandra
    nodes goes down.
  • Clustering: All Kong nodes auto-join the cluster keeping their config
    updated across nodes.
  • Scalability: Distributed by nature, Kong scales horizontally by simply
    adding nodes.
  • Performance: Kong handles load with ease by scaling and using NGINX at
    the core.
  • Plugins: Extendable architecture for adding functionality to Kong and
    APIs.

For more info about plugins and integrations, you can check out the Kong
Hub
.

Development

If you are planning on developing on Kong, you'll need a development
installation. The next branch holds the latest unreleased source code.

You can read more about writing your own plugins in the Plugin Development
Guide
, or browse an
online version of Kong's source code documentation in the Plugin Development
Kit (PDK) Reference
.

Docker

You can use Docker / docker-compose and a mounted volume to develop Kong by
following the instructions on Kong/kong-build-tools.

Vagrant

You can use a Vagrant box running Kong and Postgres that you can find at
Kong/kong-vagrant.

Source Install

Kong mostly is an OpenResty application made of Lua source files, but also
requires some additional third-party dependencies. We recommend installing
those by following the source install instructions at
https://docs.konghq.com/install/source/.

Instead of following the second step (Install Kong), clone this repository
and install the latest Lua sources instead of the currently released ones:

$ git clone https://github.com/Kong/kong
$ cd kong/

# you might want to switch to the development branch. See CONTRIBUTING.md
$ git checkout next

# install the Lua sources
$ luarocks make

Running for development

Check out the development section
of the default configuration file for properties to tweak in order to ease
the development process for Kong.

Modifying the lua_package_path
and lua_package_cpath
directives will allow Kong to find your custom plugin's source code wherever it
might be in your system.

Tests

Install the development dependencies ([busted], [luacheck]) with:

$ make dev

Kong relies on three test suites using the [busted] testing library:

  • Unit tests
  • Integration tests, which require Postgres and Cassandra to be up and running
  • Plugins tests, which require Postgres to be running

The first can simply be run after installing busted and running:

$ make test

However, the integration and plugins tests will spawn a Kong instance and
perform their tests against it. As so, consult/edit the spec/kong_tests.conf
configuration file to make your test instance point to your Postgres/Cassandra
servers, depending on your needs.

You can run the integration tests (assuming both Postgres and Cassandra are
running and configured according to spec/kong_tests.conf) with:

$ make test-integration

And the plugins tests with:

$ make test-plugins

Finally, all suites can be run at once by simply using:

$ make test-all

Consult the run_tests.sh script for a more advanced example
usage of the tests suites and the Makefile.

Finally, a very useful tool in Lua development (as with many other dynamic
languages) is performing static linting of your code. You can use luacheck for this:

$ make lint

Makefile

When developing, you can use the Makefile for doing the following operations:

Name Description
install Install the Kong luarock globally
dev Install development dependencies
lint Lint Lua files in kong/ and spec/
test Run the unit tests suite
test-integration Run the integration tests suite
test-plugins Run the plugins test suite
test-all Run all unit + integration + plugins tests at once

Enterprise Support & Demo

If you are working in a large organization you should learn more about Kong
Enterprise
.

GitHub