Merge pull request #49 from libp2p/readme-update

Add install, usage & addressing info to README

README.md

@@ -8,10 +8,33 @@
 [![Coverage Status](https://coveralls.io/repos/github/libp2p/go-ws-transport/badge.svg?branch=master)](https://coveralls.io/github/libp2p/go-ws-transport?branch=master)
 [![Build Status](https://travis-ci.org/libp2p/go-ws-transport.svg?branch=master)](https://travis-ci.org/libp2p/go-ws-transport)
 
-> go-libp2p websocket transport
+> A libp2p transport implementation using WebSockets
+
+`go-ws-transport` is an implementation of the [libp2p transport
+interface][concept-transport] that streams data over
+[WebSockets][spec-websockets], which are themselves layered over TCP/IP. It is
+included by default in the main [`go-libp2p`][go-libp2p] "entry point" module.
+
+## Table of Contents
+
+- [go-ws-transport](#go-ws-transport)
+    - [Table of Contents](#table-of-contents)
+    - [Install](#install)
+    - [Usage](#usage)
+    - [Addresses](#addresses)
+    - [Security and Multiplexing](#security-and-multiplexing)
+    - [Contribute](#contribute)
+        - [Want to hack on IPFS?](#want-to-hack-on-ipfs)
+    - [License](#license)
 
 ## Install
 
+`go-ws-transport` is included as a dependency of `go-libp2p`, which is the most
+common libp2p entry point. If you depend on `go-libp2p`, there is generally no
+need to explicitly depend on this module.
+
+`go-ws-transport` is a standard Go module which can be installed with:
+
 ```sh
 > go get github.com/libp2p/go-ws-transport
 ```
@@ -23,16 +46,85 @@ or by editing your `go.mod` file as [described by the gomod documentation](https
 
 ## Usage
 
+WebSockets are one of the default transports enabled when constructing a standard libp2p
+Host, along with [TCP](https://github.com/libp2p/go-tcp-transport).
+
+Calling [`libp2p.New`][godoc-libp2p-new] to construct a libp2p Host will enable
+the WebSocket transport, unless you override the default transports by passing in
+`Options` to `libp2p.New`.
+
+To explicitly enable the WebSocket transport while constructing a host, use the
+`libp2p.Transport` option, passing in the `ws.New` constructor function:
+
+``` go
+
+import (
+    "context"
+
+    libp2p "github.com/libp2p/go-libp2p"
+    ws "github.com/libp2p/go-ws-transport"
+)
+
+ctx := context.Background()
+
+// WebSockets only:
+h, err := libp2p.New(ctx,
+    libp2p.Transport(ws.New)
+)
+```
+
+The example above will replace the default transports with a single WebSocket
+transport. To add multiple tranports, use `ChainOptions`:
+
+``` go
+// WebSockets and QUIC:
+h, err := libp2p.New(ctx,
+    libp2p.ChainOptions(
+        libp2p.Transport(ws.New),
+        libp2p.Transport(quic.NewTransport)) // see https://github.com/libp2p/go-libp2p-quic-transport
+)
+```
+
+## Addresses
+
+The WebSocket transport supports [multiaddrs][multiaddr] that contain a `ws`
+component, which is encapsulated within (or layered onto) another valid TCP
+multiaddr.
+
+Examples:
+
+| addr                          | description                                        |
+|-------------------------------|----------------------------------------------------|
+| `/ip4/1.2.3.4/tcp/1234/ws`    | IPv4: 1.2.3.4, TCP port 1234                       |
+| `/ip6/::1/tcp/1234/ws`        | IPv6 loopback, TCP port 1234                       |
+| `/dns4/example.com/tcp/80/ws` | DNS over IPv4, hostname `example.com`, TCP port 80 |
+
+Notice that the `/ws` multiaddr component contextualizes an existing TCP/IP
+multiaddr and does not require any additional addressing information.
+
+## Security and Multiplexing
+
+While the WebSocket spec defines a `wss` URI scheme for encrypted WebSocket
+connections, support for `wss` URIs relies on TLS, which wraps the WebSocket
+connection in a similar manner to TLS-protected HTTP traffic.
+
+As libp2p does not integrate with the TLS Certificate Authority infrastructure
+by design, security for WebSockets is provided by a [transport
+upgrader][transport-upgrader]. The transport upgrader negotiates transport
+security for each connection according to the protocols supported by each party.
+
+The transport upgrader also negotiates a stream multiplexing protocol to allow
+many bidirectional streams to coexist on a single WebSocket connection.
 
 ## Contribute
 
 Feel free to join in. All welcome. Open an [issue](https://github.com/libp2p/go-ws-transport/issues)!
 
-This repository falls under the IPFS [Code of Conduct](https://github.com/ipfs/community/blob/master/code-of-conduct.md).
+This repository falls under the libp2p [Code of Conduct](https://github.com/libp2p/community/blob/master/code-of-conduct.md).
 
-### Want to hack on IPFS?
+### Want to hack on libp2p?
 
-[![](https://cdn.rawgit.com/jbenet/contribute-ipfs-gif/master/img/contribute.gif)](https://github.com/ipfs/community/blob/master/contributing.md)
+[![](https://cdn.rawgit.com/libp2p/community/master/img/contribute.gif)](https://github.com/libp2p/community/blob/master/CONTRIBUTE.md)
 
 ## License
 
@@ -41,3 +133,12 @@ MIT
 ---
 
 The last gx published version of this module was: 2.0.27: QmaSWc4ox6SZQF6DHZvDuM9sP1syNajkKuPXmKR1t5BAz5
+
+<!-- reference links -->
+[go-libp2p]: https://github.com/libp2p/go-libp2p
+[concept-transport]: https://docs.libp2p.io/concepts/transport/
+[interface-host]: https://github.com/libp2p/go-libp2p-core/blob/master/host/host.go
+[godoc-libp2p-new]: https://godoc.org/github.com/libp2p/go-libp2p#New
+[transport-upgrader]: https://github.com/libp2p/go-libp2p-transport-upgrader
+[multiaddr]: https://github.com/multiformats/multiaddr
+[spec-websockets]: https://tools.ietf.org/html/rfc6455