- Example use case
- ">Architecture
有应用商店的意思, 但是没看懂没什么一定要和 cloud provider 有关系.
link: here
Service Catalog is an extension API that enables applications running in Kubernetes clusters to easily use external managed software offerings, such as a datastore service offered by a cloud provider.
It provides a way to list, provision, and bind with external Managed Services from Service Brokers without needing detailed knowledge about how those services are created or managed.
A service broker, as defined by the Open service broker API spec, is an endpoint for a set of managed services offered and maintained by a third-party, which could be a cloud provider such as AWS, GCP, or Azure. Some examples of managed services are Microsoft Azure Cloud Queue, Amazon Simple Queue Service, and Google Cloud Pub/Sub, but they can be any software offering that can be used by an application.
Using Service Catalog, a cluster operator can browse the list of managed services offered by a service broker, provision an instance of a managed service, and bind with it to make it available to an application in the Kubernetes cluster.
Example use case
An application developer wants to use message queuing as part of their application running in a Kubernetes cluster. However, they do not want to deal with the overhead of setting such a service up and administering it themselves. Fortunately, there is a cloud provider that offers message queuing as a managed service through its service broker.
A cluster operator can setup Service Catalog and use it to communicate with the cloud provider’s service broker to provision an instance of the message queuing service and make it available to the application within the Kubernetes cluster. The application developer therefore does not need to be concerned with the implementation details or management of the message queue. The application can simply use it as a service.
Architecture
Service Catalog uses the Open service broker API to communicate with service brokers, acting as an intermediary for the Kubernetes API Server to negotiate the initial provisioning and retrieve the credentials necessary for the application to use a managed service.
It is implemented as an extension API server and a controller, using etcd for storage. It also uses the aggregation layer available in Kubernetes 1.7+ to present its API.