# Pinniped

## Overview

Pinniped provides identity services to Kubernetes.

Pinniped allows cluster administrators to easily plug in external identity
providers (IDPs) into Kubernetes clusters. This is achieved via a uniform
install procedure across all types and origins of Kubernetes clusters,
declarative configuration via Kubernetes APIs, enterprise-grade integrations
with IDPs, and distribution-specific integration strategies.

### Example Use Cases

* Your team uses a large enterprise IDP, and has many clusters that they
  manage. Pinniped provides:
  * Seamless and robust integration with the IDP
  * Easy installation across clusters of any type and origin
  * A simplified login flow across all clusters
* Your team shares a single cluster. Pinniped provides:
  * Simple configuration to integrate an IDP
  * Individual, revocable identities

### Architecture

Pinniped offers credential exchange to enable a user to exchange an external IDP 
credential for a short-lived, cluster-specific credential. Pinniped supports various
IDP types and implements different integration strategies for various Kubernetes
distributions to make authentication possible.

The currently supported external IDP types are outlined here. More will be added in the future.

1. Any webhook which implements the 
[Kubernetes TokenReview API](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#webhook-token-authentication)

The currently supported cluster integration strategies are outlined here. More
will be added in the future.

1. Pinniped hosts a credential exchange API via a Kubernetes aggregated API server.
This API returns a new cluster-specific credential using the cluster's signing keypair to
issue short-lived cluster certificates. (In the future, when the Kubernetes CSR API
provides a way to create a short-lived certificate, then the Pinniped credential exchange API
will use that instead of using the cluster's signing keypair.)

With any of the above IDPs and integration strategies, `kubectl` commands receive the
cluster-specific credential via a 
[Kubernetes client-go credential plugin](https://kubernetes.io/docs/reference/access-authn-authz/authentication/#client-go-credential-plugins).
Users may use the Pinniped CLI as the credential plugin, or they may use any proprietary CLI
built with the [Pinniped Go client library](generated).

#### Cluster Authentication Sequence Diagram

![implementation](doc/img/pinniped.svg)

## Installation

Currently, Pinniped supports self-hosted clusters where the Kube Controller Manager pod
is accessible from Pinniped's pods.
Support for other types of Kubernetes distributions is coming soon.

To try Pinniped, see [deploy/README.md](deploy/README.md).

## Contributions

Contributions are welcome. Before contributing, please see
the [Code of Conduct](doc/code-of-conduct.md) and 
[the contributing guide](doc/contributing.md).

## License

Pinniped is open source and licensed under Apache License Version 2.0. See [LICENSE](LICENSE) file.

Copyright 2020 VMware, Inc.