The Lightning Network is specified in the lightning-rfc by the open source community.
The lightning-rfc is also called Basics of Lightning Technology (BOLT) which is a collection of documents (BOLTs) that specify the components needed for the protocol.
There are several teams who implement the BOLTs as software which you can run on your computer or a server.
All those teams also contribute to the BOLTs.
In this chapter you will learn how to set up each of the software packages for each of the Lightning Network implementations.
We presented them in alphabetical order to emphasize that we generally do not prefer or recommend one over the other.
It will depend on your preferences which of the software packages you might want to work with.
== Lightning Node Software
As we've seenin previous chapters, a Lightning node is a computer system that participates in the Lightning Network. The Lightning Network is not a product or company - it is a set of open standards that define a baseline for interoperability. As such, Lightning node software has been built by a variety of companies and community groups. The vast majority of Lightning software is _open source_, meaning that the source code is open and licensed in such as way as to enable collaboration, sharing and community participation in the development process. Similarly, the Lightning node implementations we will show in this chapter are all open source and collaborative developed.
Unlike Bitcoin, where the standard is defined by a _reference implementation_ in software (Bitcoin Core), in Lightning the standard is defined by a series of standards documents called _Basis of Lightning Technology (BOLT)_, found at the lightning-rfc repository at:
https://github.com/lightningnetwork/lightning-rfc
There is no reference implementation of the Lightning Network, but there are several competing, BOLT-compliant and interoperable implementations developed by different teams and organizations. The teams that develop software for the Lightning Network also contribute in the development and evolution of the BOLTs.
Another major difference between Lightning node software and Bitcoin node software is that Lightning nodes do not need to operate in "lockstep" with consensus rules, and can have extended functionality beyond the baseline of the BOLTS. Therefore, different teams may pursue various experimental features that, if successful and broadly deployed, may become part of the BOLTs later.
In this chapter you will learn how to set up each of the software packages for the most popular Lightning node implementations. We've presented them in alphabetical order to emphasize that we generally do not prefer or recommend one over the other. Each has its strengths and weaknesses and choosing one will depend on a variety of factors. Since they are developed in different programming languages (e.g. Go, C, etc.) your choice may also depend on your level of familiarity and expertise with a specific language and development toolset.
=== Lightning Development Environment
((("development environment", "setup")))If you're a developer, you will want to set up a development environment with all the tools, libraries, and support software for writing and running Lightning software. In this highly technical chapter, we'll walk through that process step-by-step. If the material becomes too dense (and you're not actually setting up a development environment) feel free to skip to the next chapter, which is less technical.
==== Using the command-line
The examples in this chapter, and more broadly in most of this book, use a command-line terminal. That means that you type commands into a terminal and receive text responses. Furthermore, the examples are demonstrated on an operating system based on the Linux kernel and GNU software system, specifically the latest long-term stable release of Ubuntu (Ubuntu 18.04 LTS). The majority of the examples can be replicated on other operating systems such as Windows or Mac OS, with small modifications to the commands. The biggest difference between operating systems is the _package manager_ which installs the various software libraries and pre-requisites. In the examples, we will use +apt+, which is the package manager for Ubuntu. In Mac OS, an common package manager used for open source development is Homebrew (command +brew+) found at https://brew.sh.
Many developers also use a _container_, which is a type of virtual machine, to install a pre-configured operating system and application with all the necessary dependencies. Much of the Lightning software can also be installed using a container system such as _Docker_ (command +docker+) found at https://docker.com. Container installations are a lot easier, especially for those who are not used to a command-line environment.
In most of the examples here, we will be building the software directly from the source code, which gives us the most power and control, but can be quite challenging. You may choose to use a docker container, pre-compiled package or other installation mechanism instead if you get stuck!
[TIP]
====
((("$ symbol")))((("shell commands")))((("terminal applications")))In many of the examples in this chapter we will be using the operating system's command-line interface (also known as a "shell"), accessed via a "terminal" application. The shell will display a prompt; you type a command; and the shell responds with some text and a new prompt for your next command. The prompt may look different on your system, but in the following examples it is denoted by a +$+ symbol. In the examples, when you see text after a +$+ symbol, don't type the +$+ symbol but type the command immediately following it, then press Enter to execute the command. In the examples, the lines below each command are the operating system's responses to that command. When you see the next +$+ prefix, you'll know it's a new command and you should repeat the process.
Andreas M. Antonopoulos
4 years ago