The Kubernetes service catalog project allows you to integrate smoothly and painlessly any external service that support the Open Service Broker API specification:

https://github.com/openservicebrokerapi/servicebroker

The intention of the open service broker API is to expose external services to any cloud environment through a standard specification with supporting documentation and a comprehensive test suite. That lets providers implement a single specification and supports multiple cloud environments. The current environments include Kubernetes and CloudFoundry. The project works towards broad industry adoption.

The service catalog is particularly useful for integrating the services of cloud platform providers. Here are some examples of such services:

• Microsoft Azure Cloud Queue
• Amazon Simple Queue Service
• Google Cloud Pub/Sub

This capability is a boon for organizations that are committed to the cloud. You get to build your system on Kubernetes, but you don't have to deploy, manage, and maintain every service in your cluster yourself. You can offload that to your cloud provider, enjoy deep integration, and focus on your application.

The service catalog can potentially make your Kubernetes cluster fully autonomous by allowing you to provision cloud resources through service brokers. We're not there yet, but the direction is very promising.

This concludes our discussion of accessing and extending Kubernetes from the outside. In the next section, we will direct our gaze inward and look into customizing the inner workings of Kubernetes itself via plugins.