store

Documentation

Overview

Package store is a work-in-progress package that gives access to data storage for P2 objects. As of the writing of this comment (12-22-16) there's nothing here, because up until this point all of our storage code is consul-specific and consul-specific semantics have leaked into our APIs.

Any new storage code should have its interface expressed in terms of P2 types only, e.g. GetPodIntent(types.NodeName, types.PodID) (manifest.Manifest, error) instead of Pod(types.PodPrefix, types.NodeName, types.PodID) (manifest.Manifest, error), which exposes "pod prefix" which directly maps to a consul keyspace (e.g. "/intent" or "/reality").

The idea is that any code that imports a type from pkg/store can easily switch backends.

For example, imagine a pkg/foo that defines an RCGetter interface and a Foo type:

type RCGetter interface {
  GetRC(rc_fields.ID) (rc_fields.ReplicationController, error)
}

func New(RCGetter) Foo { ... }

With this scheme, code instantiating a Foo can easily choose a backend to use, e.g. by using foo.New(store.NewConsul()), foo.New(store.NewETCD()), or foo.New(store.NewFancyGRPCClient()).