As we have seen in 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 a way as to enable collaboration, sharing and community participation in the development process. Similarly, the Lightning node implementations we will present in this chapter are all open source and are collaboratively developed.
As we have seen in 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 a way as to enable collaboration, sharing, and community participation in the development process. Similarly, the Lightning node implementations we will present in this chapter are all open source and are collaboratively 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:
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 https://github.com/lightningnetwork/lightning-rfc[_lightning-rfc_] repository.
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 BOLT standards.
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 BOLT standards.
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.
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 endorse 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.
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 endorse 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
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 or you're not actually setting up a development environment, then feel free to skip to the next chapter, which is less technical.
==== Using the Command-Line
==== Using the CommandLine
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 20.04 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 their pre-requisites. In the given examples, we will use +apt+, which is the package manager for Ubuntu. On Mac OS, a common package manager used for open source development is Homebrew (command +brew+) found at https://brew.sh.
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 20.04 LTS). The majority of the examples can be replicated on other operating systems such as Windows or macOS, with small modifications to the commands. The biggest difference between operating systems is the _package manager_ that installs the various software libraries and their pre-requisites. In the given examples, we will use +apt+, which is the package manager for Ubuntu. On macOS, a common package manager used for open source development is https://brew.sh[Homebrew], which is accessed by the command +brew+.
In most of the examples here, we will be building the software directly from the source code. While this can be quite challenging, it gives us the most power and control. You may choose to use Docker containers, pre-compiled packages or other installation mechanisms instead if you get stuck!
In most of the examples here, we will be building the software directly from the source code. While this can be quite challenging, it gives us the most power and control. You may choose to use Docker containers, precompiled packages, or other installation mechanisms instead if you get stuck!
[TIP]
====
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 first display a prompt as an indicator that it is ready for your command. Then you type a command and press "Enter" to which 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 +$+ symbol but type the command immediately following it. Then press the Enter key to execute the command. In the examples, the lines below each command are the operating system's responses to that command. When you see the next +$+ prefix, you'll know it is a new command and you should repeat the process.
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 first display a prompt as an indicator that it is ready for your command. Then you type a command and press the Enter key, to which 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 +$+ symbol but type the command immediately following it. Then press the Enter key to execute the command. In the examples, the lines following each command are the operating system's responses to that command. When you see the next +$+ prefix, you'll know it is a new command and you should repeat the process.
====
To keep things consistent, we use the +bash+ shell in all command-line examples. While other shells will behave in a similar way, and you will be able to run all the examples without it, some of the shell scripts are written specifically for the +bash+ shell and may require some changes or customizations to run in another shell. For consistency, you can install the +bash+ shell on Windows and Mac OS, and it comes installed by default on most Linux systems.
To keep things consistent, we use the +bash+ shell in all command-line examples. While other shells will behave in a similar way, and you will be able to run all the examples without it, some of the shell scripts are written specifically for the +bash+ shell and may require some changes or customizations to run in another shell. For consistency, you can install the +bash+ shell on Windows and macOS, and it comes installed by default on most Linux systems.
==== Downloading the Book Repository
All the code examples are available in the book's online repository. Because the repository will be kept up-to-date as much as possible, you should always look for the latest version in the online repository instead of copying it from the printed book or the ebook.
You can download the repository as a ZIP bundle by visiting https://github.com/lnbook/lnbook/ and selecting the green "Clone or Download" button on the right.
You can download the repository as a ZIP bundle by visiting https://github.com/lnbook/lnbook/[GitHub] and selecting the green Code button on the right.
Alternatively, you can use the +git+ command to create a version-controlled clone of the repository on your local computer. Git is a distributed version control system that is used by most developers to collaborate on software development and track changes to software repositories. Download and install +git+ by following the instructions on https://git-scm.com/.
Alternatively, you can use the +git+ command to create a version-controlled clone of the repository on your local computer. Git is a distributed version control system that is used by most developers to collaborate on software development and track changes to software repositories. Download and install +git+ by following the instructions https://git-scm.com/[from the Git Project].
To make a local copy of the repository on your computer, run the git command as follows:
To make a local copy of the repository on your computer, run the +git+ command as follows:
[[git-clone-lnbook]]
----
@ -58,15 +56,15 @@ All subsequent examples will assume that you are running commands from inside th
=== Docker Containers
Many developers use a _container_, which is a type of virtual machine, to install a pre-configured operating system and applications with all the necessary dependencies. Much of the Lightning software can also be installed using a container system such as _Docker_ found at https://docker.com. Container installations are a lot easier, especially for those who are not used to a command-line environment.
Many developers use a _container_, which is a type of virtual machine, to install a pre-configured operating system and applications with all the necessary dependencies. Much of the Lightning software can also be installed using a container system such as _Docker_ found at https://docker.com[the Docker home page]. Container installations are a lot easier, especially for those who are not used to a command-line environment.
The book's repository contains a collection of Docker containers that can be used to set up a consistent development environment to practice and replicate the examples on any system. Because the container is a complete operating system that runs with a consistent configuration, you can be sure that the examples will work on your computer without the need to worry about dependencies, library versions or differences in configuration.
The book's repository contains a collection of Docker containers that can be used to set up a consistent development environment to practice and replicate the examples on any system. Because the container is a complete operating system that runs with a consistent configuration, you can be sure that the examples will work on your computer without the need to worry about dependencies, library versions, or differences in configuration.
Docker containers are often optimized to be small, i.e. occupy the minimum disk space. However, in this book we are using containers to _standardize_ the environment and make it consistent for all readers. Furthermore, these containers are not meant to be used to run services in the background. Instead, they are meant to be used to test the examples and learn by interacting with the software. For these reasons, the containers are quite large and come with a lot of development tools and utilities. Commonly the Alpine distribution is used for Linux containers due to their reduced size. Nonetheless, we provide containers built on Ubuntu because more developers are familiar with Ubuntu, and this familiarity is more important to us than size.
Docker containers are often optimized to be small, i.e., occupy the minimum disk space. However, in this book we are using containers to _standardize_ the environment and make it consistent for all readers. Furthermore, these containers are not meant to be used to run services in the background. Instead, they are meant to be used to test the examples and learn by interacting with the software. For these reasons, the containers are quite large and come with a lot of development tools and utilities. Commonly the Alpine distribution is used for Linux containers due to their reduced size. Nonetheless, we provide containers built on Ubuntu because more developers are familiar with Ubuntu, and this familiarity is more important to us than size.
The installation of use of Docker and its commands is detailed in <<appendix_docker>>. If you are unfamiliar with Docker, now is a good time to quickly review that section.
You can find the latest container definitions and build configurations in the book's repository under the +code/docker+ folder. Each container is in a separate folder as can be seen below:
You can find the latest container definitions and build configurations in the book's repository under the _code/docker_ folder. Each container is in a separate folder as can be seen in the following:
[[tree]]
----
@ -124,17 +122,17 @@ code/docker
`-- run-payment-demo.sh*
----
As we will see in the next few sections, you can build these containers locally, or you can pull them from the book's repository on _Docker Hub_. The following sections will assume that you have installed Docker and are familiar with the basic use of the +docker+ command.
As we will see in the next few sections, you can build these containers locally, or you can pull them from the book's repository on https://hub.docker.com/orgs/lnbook[_Docker Hub_]. The following sections will assume that you have installed Docker and are familiar with the basic use of the +docker+ command.
=== Bitcoin Core and Regtest
Most of the Lightning node implementations need access to a full Bitcoin node in order to work.
Most of the Lightning node implementations need access to a full Bitcoin node to work.
Installing a full Bitcoin node and syncing the Bitcoin blockchain is outside the scope of this book and is a relatively complex endeavor in itself. If you want to try it, refer to _Mastering Bitcoin_ (https://github.com/bitcoinbook/bitcoinbook), "Chapter 3: Bitcoin Core: The Reference Implementation" which discusses the installation and operation of a Bitcoin node.
Installing a full Bitcoin node and syncing the Bitcoin blockchain is outside the scope of this book and is a relatively complex endeavor in itself. If you want to try it, refer to https://github.com/bitcoinbook/bitcoinbook[_Mastering Bitcoin_], "Chapter 3: Bitcoin Core: The Reference Implementation," which discusses the installation and operation of a Bitcoin node.
A Bitcoin node can be operated in _regtest_ mode, where the node creates a local simulated Bitcoin blockchain for testing purposes. In the following examples, we will be using the +regtest+ mode to allow us to demonstrate Lightning without having to synchronize a Bitcoin node or risk any funds.
The container for Bitcoin Core is +bitcoind+. It is configured to run Bitcoin Core in +regtest+ mode and to mine 6 new blocks every 10 seconds. Its RPC port is exposed on port 18443 and accessible for RPC calls with the username +regtest+ and the password +regtest+. You can also access it with an interactive shell and run +bitcoin-cli+ commands locally.
The container for Bitcoin Core is +bitcoind+. It is configured to run Bitcoin Core in +regtest+ mode and to mine six new blocks every 10 seconds. Its remote procedure call (RPC) port is exposed on port 18443 and accessible for RPC calls with the username +regtest+ and the password +regtest+. You can also access it with an interactive shell and run +bitcoin-cli+ commands locally.
Alternatively, you can build the container yourself from the local container definition that is in +code/docker/bitcoind/Dockerfile+.
Alternatively, you can build the container yourself from the local container definition that is in _code/docker/bitcoind/Dockerfile_.
[NOTE]
====
You don't need to build the container if you used the "pull" command previously to pull it from Docker Hub
You don't need to build the container if you used the +pull+ command previously to pull it from Docker Hub.
====
Building the container locally will use a bit less of your network bandwidth, but will take more of your CPU time to build. We use the +docker build+ command to build it:
@ -210,7 +208,7 @@ For now, there are no transactions. But we have some test bitcoin that has been
===== Interacting with the bitcoin core container
In the meantime, we can also interact with the +bitcoind+ container by sending it shell commands. The container is sending a logfile to the terminal, displaying the mining process of the bitcoind process. To interact with the shell we can issue commands in another terminal, using the +docker exec+ command. Since we previously named the running container with the +name+ argument, we can refer to it by that name when we run the +docker exec+ command. First, let's run an interactive +bash+ shell:
In the meantime, we can also interact with the +bitcoind+ container by sending it shell commands. The container is sending a logfile to the terminal, displaying the mining process of the +bitcoind+ process. To interact with the shell we can issue commands in another terminal, using the +docker exec+ command. Since we previously named the running container with the +name+ argument, we can refer to it by that name when we run the +docker exec+ command. First, let's run an interactive +bash+ shell:
----
$ docker exec -it bitcoind /bin/bash
@ -224,7 +222,7 @@ root@e027fd56e31a:/bitcoind# ps x
root@e027fd56e31a:/bitcoind#
----
Running the interactive shell puts us "inside" the container. It logs in as user +root+, as we can see from the prefix +root@+ in the new shell prompt +root@e027fd56e31a:/bitcoind#+. If we issue the +ps x+ command to see what processes are running, we see both +bitcoind+ and the script +mine.sh+ are running in the background. To exit this shell, type +CTRL-D+ or +exit+ and you will be returned to your operating system prompt.
Running the interactive shell puts us "inside" the container. It logs in as user +root+, as we can see from the prefix +root@+ in the new shell prompt +root@e027fd56e31a:/bitcoind#+. If we issue the +ps x+ command to see what processes are running, we see both +bitcoind+ and the script +mine.sh+ are running in the background. To exit this shell, type *+CTRL-D+* or *+exit+*, and you will be returned to your operating system prompt.
Instead of running an interactive shell, we can also issue a single command that is executed inside the container. For convenience, the +bitcoin-cli+ command has an alias "cli" that passes the correct configuration. So let's run it to ask Bitcoin Code about the blockchain. We run +cli getblockchaininfo+:
The +cli+ command in the bitcoind container allows us to issue RPC commands to the Bitcoin Core node and get JSON-encoded results.
The +cli+ command in the +bitcoind+ container allows us to issue RPC commands to the Bitcoin Core node and get JavaScript Object Notation (JSON) encoded results.
Additionally, all our docker containers have a command-line JSON encoder/decoder named +jq+ preinstalled. +jq+ helps us to process JSON-formatted data via the command-line or from inside scripts. You can send the JSON output of any command to +jq+ using the +|+ character. This character as well as this operation is called a "pipe". Let's apply a +pipe+ and +jq+ to the previous command as follows:
Additionally, all our Docker containers have a command-line JSON encoder/decoder named +jq+ preinstalled. +jq+ helps us to process JSON-formatted data via the commandline or from inside scripts. You can send the JSON output of any command to +jq+ using the +|+ character. This character as well as this operation is called a "pipe." Let's apply a +pipe+ and +jq+ to the previous command as follows:
+jq .blocks+ instructs the +jq+ JSON decoder to extract the field +blocks+ from the +getblockchaininfo+ result. In our case, it extracts and prints the value of 197 which we could use in a subsequent command.
+jq .blocks+ instructs the +jq+ JSON decoder to extract the field +blocks+ from the [.keep-together]#+getblockchaininfo+# result. In our case, it extracts and prints the value of 197 which we could use in a subsequent command.
As you will see in the following sections, we can run several containers at the same time and then interact with them individually. We can issue commands to extract information such as the Lightning node public key or to take actions such as opening a Lightning channel to another node. The +docker run+ and +docker exec+ commands together with +jq+ for JSON decoding are all we need to build a working Lightning Network that mixes many different node implementations. This enables us to try out diverse experiments on our own computer.
=== The c-lightning Lightning Node Project
C-lightning is a lightweight, highly customizable, and standard-compliant implementation of the Lightning Network protocol, developed by Blockstream as part of the Elements project. The project is open source and developed collaboratively on Github:
https://github.com/ElementsProject/lightning
c-lightning is a lightweight, highly customizable, and standard-compliant implementation of the LN protocol, developed by Blockstream as part of the Elements Project. The project is open source and developed collaboratively on https://github.com/ElementsProject/lightning[GitHub].
In the following sections, we will build a Docker container that runs a c-lightning node connecting to the bitcoind container we built previously. We will also show you how to configure and build the c-lightning software directly from the source code.
In the following sections, we will build a Docker container that runs a c-lightning node connecting to the +bitcoind+ container we built previously. We will also show you how to configure and built the c-lightning software directly from the source code.
==== Building c-lightning As a Docker Container
The c-lightning software distribution has a Docker container, but it is designed for running c-lightning in production systems and along side a bitcoind node. We will be using a somewhat simpler container configured to run c-lightning for demonstration purposes.
The c-lightning software distribution has a Docker container, but it is designed for running c-lightning in production systems and along side a +bitcoind+ node. We will be using a somewhat simpler container configured to run c-lightning for demonstration purposes.
Let's pull the c-lightning container from the book's Docker Hub repository:
Alternatively, we can build the c-lightning Docker container from the book's files which you previously downloaded into a directory named +lnbook+. As before, we will use the +docker build+ command in the +code/docker+ sub-directory. We will tag the container image with the tag +lnbook/c-lightning+ like this:
Alternatively, we can build the c-lightning Docker container from the book's files which you previously downloaded into a directory named +lnbook+. As before, we will use the +docker build+ command in the +code/docker+ subdirectory. We will tag the container image with the tag +lnbook/c-lightning+ like this:
Our container is now built and ready to run. However, before we run the c-lightning container, we need to start the bitcoind container in another terminal as c-lightning depends on bitcoind. We will also need to set up a Docker network that allows the containers to connect to each other as if residing on the same local area network.
Our container is now built and ready to run. However, before we run the c-lightning container, we need to start the +bitcoind+ container in another terminal because c-lightning depends on +bitcoind+. We will also need to set up a Docker network that allows the containers to connect to each other as if residing on the same local area network.
[TIP]
====
Docker containers can "talk" to each other over a virtual local area network managed by the Docker system. Each container can have a custom name and other containers can use that name to resolve its IP address and easily connect to it.
Docker containers can "talk" to each other over a virtual local area network managed by the Docker system. Each container can have a custom name, and other containers can use that name to resolve its IP address and easily connect to it.
====
==== Setting Up a Docker Network
Once a Docker network is set up, Docker will activate the network on our local computer every time Docker starts, e.g. after rebooting. So we only need to set up a network once by using the +docker network create+ command. The network name itself is not important, but it has to be unique on our computer. By default, Docker has three networks named +host+, +bridge+, and +none+. We will name our new network +lnbook+ and create it like this:
Once a Docker network is set up, Docker will activate the network on our local computer every time Docker starts, e.g., after rebooting. So we only need to set up a network once by using the +docker network create+ command. The network name itself is not important, but it has to be unique on our computer. By default, Docker has three networks named +host+, +bridge+, and +none+. We will name our new network +lnbook+ and create it like this:
[source,bash]
----
@ -333,18 +329,18 @@ ad75c0e4f87e lnbook bridge local
ee8824567c95 none null local
----
As you can see, running +docker network ls+ gives us a listing of the Docker networks. Our +lnbook+ network has been created. We can ignore the network ID, as it is automatically managed.
As you can see, running +docker network ls+ gives us a listing of the Docker networks. Our +lnbook+ network has been created. We can ignore the network ID, because it is automatically managed.
==== Running the bitcoind and c-lightning Containers
The next step is to start the bitcoind and c-lightning containers and connect them to the +lnbook+ network. To run a container in a specific network, we must pass the +network+ argument to +docker run+. To make it easy for containers to find each other, we will also give each one a name with the +name+ argument. We start bitcoind like this:
The next step is to start the +bitcoind+ and c-lightning containers and connect them to the +lnbook+ network. To run a container in a specific network, we must pass the [.keep-together]#+network+# argument to +docker run+. To make it easy for containers to find each other, we will also give each one a name with the +name+ argument. We start +bitcoind+ like this:
[source,bash]
----
$ docker run -it --network lnbook --name bitcoind lnbook/bitcoind
----
You should see bitcoind start up and start mining blocks every 10 seconds. Leave it running and open a new terminal window to start c-lightning. We use a similar +docker run+ command with the +network+ and +name+ arguments to start c-lightning as follows:
You should see +bitcoind+ start up and start mining blocks every 10 seconds. Leave it running and open a new terminal window to start c-lightning. We use a similar +docker run+ command with the +network+ and +name+ arguments to start c-lightning as follows:
[source,bash]
----
@ -362,9 +358,9 @@ lightningd: Opened log file /lightningd/lightningd.log
----
The c-lightning container starts up and connects to the bitcoind container over the Docker network. First, our c-lightning node will wait for bitcoind to start and then it will wait until bitcoind has mined some bitcoin into its wallet. Finally, as part of the container startup, a script will send an RPC command to the bitcoind node which creates a transaction that funds the c-lightning wallet with 10 test BTC. Now our c-lightning node is not only running, but it even has some test bitcoin to play with!
The c-lightning container starts up and connects to the +bitcoind+ container over the Docker network. First, our c-lightning node will wait for +bitcoind+ to start and then it will wait until +bitcoind+ has mined some bitcoin into its wallet. Finally, as part of the container startup, a script will send an RPC command to the +bitcoind+ node, which creates a transaction that funds the c-lightning wallet with 10 test BTC. Now our c-lightning node is not only running, but it even has some test bitcoin to play with!
As we demonstrated with the bitcoind container, we can issue commands to our c-lightning container in another terminal in order to extract information, open channels etc. The command that allows us to issue command-line instructions to the c-lightning node is called +lightning-cli+. This +lightning-cli+ command is also aliased as +cli+ inside this container. To get the c-lightning node's info use the following +docker exec+ command in another terminal window:
As we demonstrated with the +bitcoind+ container, we can issue commands to our c-lightning container in another terminal to extract information, open channels, etc. The command that allows us to issue command-line instructions to the c-lightning node is called +lightning-cli+. This +lightning-cli+ command is also aliased as +cli+ inside this container. To get the c-lightning node's information, use the following +docker exec+ command in another terminal window:
We now have our first Lightning node running on a virtual network and communicating with a test Bitcoin blockchain. Later in this chapter we will start more nodes and connect them to each other to make some Lightning payments.
In the next section we will also look at how to download, configure and compile c-lightning directly from the source code. This is an optional and advanced step that will teach you how to use the build tools and allow you to make modifications to c-lightning source code. With this knowledge you can write some code, fix some bugs, or create a plugin for c-lightning.
In the next section we will also look at how to download, configure, and compile c-lightning directly from the source code. This is an optional and advanced step that will teach you how to use the build tools and allow you to make modifications to [.keep-together]#c-lightning# source code. With this knowledge you can write some code, fix some bugs, or create a plug-in for c-lightning.
[NOTE]
====
@ -399,13 +395,11 @@ If you are not planning on diving into the source code or programming of a Light
==== Installing c-lightning from Source Code
The c-lightning developers have provided detailed instructions for building c-lightning from source code. We will be following the instructions here:
The c-lightning developers have provided detailed instructions for building c-lightning from source code. We will be following the instructions https://github.com/ElementsProject/lightning/blob/master/doc/INSTALL.md[from GitHub].
==== Installing Prerequisite Libraries and Packages
These installation instructions assume you are building c-lightning on a Linux or similar system with GNU build tools. If that is not the case, look for the instructions for your operating system in the ElementsProject repository above.
These installation instructions assume you are building c-lightning on a Linux or similar system with GNU build tools. If that is not the case, look for the instructions for your operating system in the ElementsProject repository.
The common first step is the installation of prerequisite libraries. We use the +apt+ package manager to install these:
@ -448,7 +442,7 @@ After a few minutes and a lot of on-screen activity, you will have installed all
==== Copying the c-lightning Source Code
Next, we will copy the latest version of c-lightning from the source code repository. To do this, we will use the +git clone+ command which clones a version-controlled copy onto your local machine thereby allowing you to keep it synchronized with subsequent changes without having to download the whole repository again:
Next, we will copy the latest version of c-lightning from the source code repository. To do this, we will use the +git clone+ command, which clones a version-controlled copy onto your local machine, thereby allowing you to keep it synchronized with subsequent changes without having to download the whole repository again:
[source,bash]
----
@ -469,12 +463,12 @@ We now have a copy of c-lightning cloned into the +lightning+ subfolder, and we
==== Compiling the c-lightning Source Code
Next, we use a set of _build scripts_ that are commonly available in many open source projects. These _build scripts_ use the +configure+ and +make+ commands which allow us to:
Next, we use a set of _build scripts_ that are commonly available in many open source projects. These build scripts use the +configure+ and +make+ commands which allow us to:
* Select the build options and check necessary dependencies (+configure+).
* Build and install the executables and libraries (+make+).
* Select the build options and check necessary dependencies (+configure+)
* Build and install the executables and libraries (+make+)
Running the +configure+ with the +help+ option will show us all the available options:
Running +configure+ with the +help+ option will show us all the available options:
----
$ ./configure --help
@ -497,7 +491,7 @@ Options include:
Compile with address-sanitizer
----
We don't need to change any of the defaults for this example. Hence we run +configure+ again without any options to use the defaults:
We don't need to change any of the defaults for this example. Hence we run [.keep-together]#+configure+# again without any options to use the defaults:
If all goes well, you will not see any +ERROR+ message stopping the execution of the above command. The c-lightning software package has been compiled from source and we are now ready to install the executable components we created in the previous step:
If all goes well, you will not see any +ERROR+ message stopping the execution of the preceding command. The c-lightning software package has been compiled from source, and we are now ready to install the executable components we created in the previous step:
In order to verify that the +lightningd+ and +lightning-cli+ commands have been installed correctly we will ask each executable for its version information:
To verify that the +lightningd+ and +lightning-cli+ commands have been installed correctly we will ask each executable for its version information:
[source,bash]
----
@ -559,19 +553,17 @@ $ lightning-cli --version
v0.10.1-34-gfe86c11
----
The version consists of the latest release version (v0.10.1) followed by the number of changes since the release (34) and finally a hash identifying exactly which revision (fe86c11). You may see a different version from that shown above as the software continues to evolve long after this book is published. However, no matter what version you see, the fact that the commands execute and respond with version information means that you have succeeded in building the c-lightning software.
The version consists of the latest release version (v0.10.1) followed by the number of changes since the release (34) and finally a hash identifying exactly which revision (fe86c11). You may see a different version from that shown previously as the software continues to evolve long after this book is published. However, no matter what version you see, the fact that the commands execute and respond with version information means that you have succeeded in building the c-lightning software.
=== The Lightning Network Daemon (LND) Node Project
The Lightning Network Daemon (LND) is a complete implementation of a Lightning Network node by Lightning Labs. The LND project provides a number of executable applications, including +lnd+ (the daemon itself) and +lncli+ (the command-line utility). LND has several pluggable back-end chain services including btcd (a full-node), bitcoind (Bitcoin Core), and neutrino (a new experimental light client). LND is written in the Go programming language. The project is open source and developed collaboratively on Github:
https://github.com/LightningNetwork/lnd
The Lightning Network Daemon (LND) is a complete implementation of an LN node by Lightning Labs. The LND project provides a number of executable applications, including +lnd+ (the daemon itself) and +lncli+ (the command-line utility). LND has several pluggable backend chain services including btcd (a full node), +bitcoind+ (Bitcoin Core), and Neutrino (a new, experimental light client). LND is written in the Go programming language. The project is open source and developed collaboratively on https://github.com/LightningNetwork/lnd[GitHub].
In the next few sections we will build a Docker container to run LND, build LND from source code, and learn how to configure and run LND.
==== The LND Docker Container
We can pull the LND example docker container from the book's Docker Hub repository:
We can pull the LND example Docker container from the book's Docker Hub repository:
[source,bash]
----
@ -590,7 +582,7 @@ docker.io/lnbook/lnd:latest
----
Alternatively, we can build the LND container locally. The container is located in +code/docker/lnd+. We change the working directory to +code/docker+ and perform the +docker build+ command:
Alternatively, we can build the LND container locally. The container is located in _code/docker/lnd_. We change the working directory to _code/docker_ and perform the +docker build+ command:
Our container is now ready to run. As with the c-lightning container we built previously, the LND container also depends on a running instance of Bitcoin Core. As before, we need to start the bitcoind container in another terminal and connect LND to it via a docker network. We have already set up a docker network called +lnbook+ previously and will be using that again here.
Our container is now ready to run. As with the c-lightning container we built previously, the LND container also depends on a running instance of Bitcoin Core. As before, we need to start the +bitcoind+ container in another terminal and connect LND to it via a docker network. We have already set up a docker network called +lnbook+ previously and will be using that again here.
[TIP]
====
Normally, each node operator runs their own Lightning node and their own Bitcoin node on their own server. For us, a single bitcoind container can serve many Lightning nodes. On our simulated network we can run several Lightning nodes, all connecting to a single Bitcoin node in regtest mode.
Normally, each node operator runs their own Lightning node and their own Bitcoin node on their own server. For us, a single +bitcoind+ container can serve many Lightning nodes. On our simulated network we can run several Lightning nodes, all connecting to a single Bitcoin node in +regtest+ mode.
====
==== Running the bitcoind and LND Containers
As before, we start the bitcoind container in one terminal and LND in another. If you already have the bitcoind container running, you do not need to restart it. Just leave it running and skip the next step. To start bitcoind in the +lnbook+ network we use +docker run+ like this:
As before, we start the +bitcoind+ container in one terminal and LND in another. If you already have the +bitcoind+ container running, you do not need to restart it. Just leave it running and skip the next step. To start +bitcoind+ in the +lnbook+ network we use +docker run+ like this:
[source,bash]
----
$ docker run -it --network lnbook --name bitcoind lnbook/bitcoind
----
Next, we start the LND container we just built. As done before we need to attach it to the +lnbook+ network and give it a name:
Next, we start the LND container we just built. As done before, we need to attach it to the +lnbook+ network and give it a name:
[source,bash]
----
@ -644,9 +636,9 @@ Funding lnd wallet
----
The LND container starts up and connects to the bitcoind container over the Docker network. First, our LND node will wait for bitcoind to start and then it will wait until bitcoind has mined some bitcoin into its wallet. Finally, as part of the container startup, a script will send an RPC command to the bitcoind node thereby creating a transaction that funds the LND wallet with 10 test BTC.
The LND container starts up and connects to the +bitcoind+ container over the docker network. First, our LND node will wait for +bitcoind+ to start and then it will wait until +bitcoind+ has mined some bitcoin into its wallet. Finally, as part of the container startup, a script will send an RPC command to the +bitcoind+ node, thereby creating a transaction that funds the LND wallet with 10 test BTC.
As we demonstrated previously, we can issue commands to our container in another terminal in order to extract information, open channels etc. The command that allows us to issue command-line instructions to the +lnd+ daemon is called +lncli+. Once again, in this container we have provided the alias +cli+ that runs +lncli+ with all the appropriate parameters. Let's get the node information using the +docker exec+ command in another terminal window:
As we demonstrated previously, we can issue commands to our container in another terminal to extract information, open channels, etc. The command that allows us to issue command-line instructions to the +lnd+ daemon is called +lncli+. Once again, in this container we have provided the alias +cli+ that runs +lncli+ with all the appropriate parameters. Let's get the node information using the +docker exec+ command in another terminal window:
[source,bash]
----
@ -661,7 +653,7 @@ $ docker exec lnd cli getinfo
}
----
We now have another Lightning node running on the +lnbook+ network and communicating with bitcoind. If you are still running the c-lightning container, then there are now two nodes running. They're not yet connected to each other, but we will be connecting them to each other soon.
We now have another Lightning node running on the +lnbook+ network and communicating with +bitcoind+. If you are still running the c-lightning container, then there are now two nodes running. They're not yet connected to each other, but we will be connecting them to each other soon.
If desired, you can run any combination of LND and c-lightning nodes on the same Lightning Network. For example, to run a second LND node you would issue the +docker run+ command with a different container name like so:
@ -670,7 +662,7 @@ If desired, you can run any combination of LND and c-lightning nodes on the same
$ docker run -it --network lnbook --name lnd2 lnbook/lnd
----
In the command above, we start another LND container, naming it +lnd2+. The names are entirely up to you, as long as they are unique. If you don't provide a name, Docker will construct a unique name by randomly combining two English words such as "naughty_einstein". This was the actual name Docker chose for us when we wrote this paragraph. How funny!
In the preceding command, we start another LND container, naming it +lnd2+. The names are entirely up to you, as long as they are unique. If you don't provide a name, Docker will construct a unique name by randomly combining two English words such as "naughty_einstein." This was the actual name Docker chose for us when we wrote this paragraph. How funny!
In the next section we will look at how to download and compile LND directly from the source code. This is an optional and advanced step that will teach you how to use the Go language build tools and allow you to make modifications to LND source code. With this knowledge you can write some code or fix some bugs.
@ -681,13 +673,11 @@ If you are not planning on diving into the source code or programming of a Light
==== Installing LND from Source Code
In this section we will build LND from scratch. LND is written in the Go programming language. IF you want to find out more about Go, search for +golang+ instead of +go+ to avoid irrelevant results. Because it is written in Go and not C or C++, it uses a different "build" framework than the GNU autotools/make framework we saw used in c-lightning previously. Don't fret though, it is quite easy to install and use the golang tools and we will show each step here. Go is a fantastic language for collaborative software development as it produces very consistent, precise, and easy to read code regardless of the number of authors. Go is focused and "minimalist" in a way that encourages consistency across versions of the language. As a compiled language, it is also quite efficient. Let's dive in.
We will follow the installation instructions found in the LND project documentation:
In this section we will build LND from scratch. LND is written in the Go programming language. If you want to find out more about Go, search for +golang+ instead of +go+ to avoid irrelevant results. Because it is written in Go and not C or C++, it uses a different "build" framework than the GNU autotools/make framework we saw used in c-lightning previously. Don't fret though, it is quite easy to install and use the golang tools, and we will show each step here. Go is a fantastic language for collaborative software development because it produces very consistent, precise, and easy-to-read code regardless of the number of authors. Go is focused and "minimalist" in a way that encourages consistency across versions of the language. As a compiled language, it is also quite efficient. Let's dive in.
We will follow the installation instructions found in the https://github.com/lightningnetwork/lnd/blob/master/docs/INSTALL.md[LND project documentation].
First, we will install the +golang+ package and associated libraries. We strictly require Go version 1.13 or later. The official Go language packages are distributed as binaries from https://golang.org/dl. For convenience they are also packaged as Debian packages available through the +apt+ command. You can follow the instructions on https://golang.org/dl or use the +apt+ commands below on a Debian/Ubuntu Linux system as described on https://github.com/golang/go/wiki/Ubuntu:
First, we will install the +golang+ package and associated libraries. We strictly require Go version 1.13 or later. The official Go language packages are distributed as binaries from https://golang.org/dl[the Go Project]. For convenience they are also packaged as Debian packages available through the +apt+ command. You can follow the instructions https://golang.org/dl[from the Go Project] or use the following +apt+ commands on a Debian/Ubuntu Linux system as described on https://github.com/golang/go/wiki/Ubuntu[GitHub's wiki page on the Go language].
[source,bash]
----
@ -702,7 +692,7 @@ $ go version
go version go1.13.4 linux/amd64
----
We have 1.13.4, so we're ready to...Go! Next we need to tell any programs where to find the Go code. This is accomplished by setting the environment variable +GOPATH+. Usually the Go code is located in a directory named +gocode+ directly in the user's home directory. With the following two commands we consistently set the +GOPATH+ and make sure your shell adds it to your executable +PATH+. Note that the user's home directory is referred to as +~+ in the shell.
We have 1.13.4, so we're ready to...Go! Next we need to tell any programs where to find the Go code. This is accomplished by setting the environment variable +GOPATH+. Usually the Go code is located in a directory named +gocode+ directly in the user's home directory. With the following two commands we consistently set the +GOPATH+ and make sure your shell adds it to your executable +PATH+. Note that the user's home directory is referred to as +~+ in the shell.
[source,bash]
----
@ -710,18 +700,18 @@ $ export GOPATH=~/gocode
$ export PATH=$PATH:$GOPATH/bin
----
To avoid having to set these environment variables every time you open a shell, you can add those two lines to the end of your bash shell configuration file +.bashrc+ in your home directory, using the editor of your choice.
To avoid having to set these environment variables every time you open a shell, you can add those two lines to the end of your +bash+ shell configuration file +.bashrc+ in your home directory, using the editor of your choice.
==== Copying the LND Source Code
As with many open source projects nowadays, the source code for LND is on Github (www.github.com). The +go get+ command can fetch it directly using the Git protocol:
As with many open source projects nowadays, the source code for LND is on GitHub (_www.github.com_). The +go get+ command can fetch it directly using the Git protocol:
[source,bash]
----
$ go get -d github.com/lightningnetwork/lnd
----
Once +go get+ finishes, you will have a sub-directory under +GOPATH+ that contains the LND source code.
Once +go get+ finishes, you will have a subdirectory under +GOPATH+ that contains the LND source code.
==== Compiling the LND Source Code
@ -733,7 +723,7 @@ $ cd $GOPATH/src/github.com/lightningnetwork/lnd
$ make && make install
----
After several minutes you will have two new commands +lnd+ and +lncli+ installed. Try them out and check their version to ensure they are installed:
After several minutes you will have two new commands, +lnd+ and +lncli+, installed. Try them out and check their version to ensure they are installed:
[source,bash]
----
@ -743,20 +733,17 @@ $ lncli --version
lncli version 0.10.99-beta commit=clock/v1.0.0-106-gc1ef5bb908606343d2636c8cd345169e064bdc91
----
You will likely see a different version from that shown above, as the software continues to evolve long after this book is published. However, no matter what version you see, the fact that the commands execute and show you version information means that you have succeeded in building the LND software.
You will likely see a different version from that shown previously, as the software continues to evolve long after this book is published. However, no matter what version you see, the fact that the commands execute and show you version information means that you have succeeded in building the LND software.
=== The Eclair Lightning Node Project
Eclair (French for Lightning) is a Scala implementation of the Lightning Network made by ACINQ. Eclair is also one of the most popular and pioneering mobile Lightning wallets which we used to demonstrate a Lightning payment in the second chapter. In this section we examine the Eclair server project which runs a Lightning node. Eclair is an open source project and can be found on GitHub:
https://github.com/ACINQ/eclair
Eclair (French for Lightning) is a Scala implementation of the Lightning Network made by ACINQ. Eclair is also one of the most popular and pioneering mobile Lightning wallets, which we used to demonstrate a Lightning payment in <<getting-started>>. In this section we examine the Eclair server project, which runs a Lightning node. Eclair is an open source project and can be found on https://github.com/ACINQ/eclair[GitHub].
In the next few sections we will build a Docker container to run Eclair, as we did previously with c-lightning and LND. We will also build Eclair directly from the source code.
==== The Eclair Docker Container
Let's pull the book's eclair container from the Docker Hub repository:
Let's pull the book's Eclair container from the Docker Hub repository:
[source,bash]
----
@ -775,7 +762,7 @@ docker.io/lnbook/eclair:latest
----
Alternatively, we can build the container locally, instead. By now, you are almost an expert in the basic operations of Docker! In this section we will repeat many of the previously seen commands to build the Eclair container. The container is located in +code/docker/eclair+. We start in a terminal by switching the working directory to +code/docker+ and issuing the +docker build+ command:
Alternatively, we can build the container locally, instead. By now, you are almost an expert in the basic operations of Docker! In this section we will repeat many of the previously seen commands to build the Eclair container. The container is located in _code/docker/eclair_. We start in a terminal by switching the working directory to _code/docker_ and issuing the +docker build+ command:
Our image is now ready to run. The Eclair container also depends on a running instance of Bitcoin Core. As before, we need to start the bitcoind container in another terminal and connect Eclair to it via a Docker network. We have already set up a Docker network called +lnbook+ and will be reusing it here.
Our image is now ready to run. The Eclair container also depends on a running instance of Bitcoin Core. As before, we need to start the +bitcoind+ container in another terminal and connect Eclair to it via a Docker network. We have already set up a Docker network called +lnbook+, and will be reusing it here.
One notable difference between Eclair and LND or c-lightning is that Eclair doesn't contain a separate bitcoin wallet but instead relies directly on the bitcoin wallet in Bitcoin Core. Recall that using LND we "funded" its bitcoin wallet by executing a transaction to transfer bitcoin from Bitcoin Core's wallet to LND's bitcoin wallet. This step is not necessary using Eclair. When running Eclair, the Bitcoin Core wallet is used directly as the source of funds to open channels. As a result, unlike the LND or c-lightning containers, the Eclair container does not contain a script to transfer bitcoin into its wallet on startup.
One notable difference between Eclair and LND or c-lightning is that Eclair doesn't contain a separate bitcoin wallet but instead relies directly on the bitcoin wallet in Bitcoin Core. Recall that using LND we funded its bitcoin wallet by executing a transaction to transfer bitcoin from Bitcoin Core's wallet to LND's bitcoin wallet. This step is not necessary using Eclair. When running Eclair, the Bitcoin Core wallet is used directly as the source of funds to open channels. As a result, unlike the LND or c-lightning containers, the Eclair container does not contain a script to transfer bitcoin into its wallet on startup.
==== Running the bitcoind and Eclair Containers
As before, we start the bitcoind container in one terminal and the Eclair container in another. If you already have the bitcoind container running, you do not need to restart it. Just leave it running and skip the next step. To start +bitcoind+ in the +lnbook+ network, we use +docker run+ like this:
As before, we start the +bitcoind+ container in one terminal and the Eclair container in another. If you already have the +bitcoind+ container running, you do not need to restart it. Just leave it running and skip the next step. To start +bitcoind+ in the +lnbook+ network, we use +docker run+ like this:
[source,bash]
----
@ -830,9 +817,9 @@ INFO fr.acinq.eclair.Setup - version=0.4.2 commit=52444b0
----
The Eclair container starts up and connects to the bitcoind container over the Docker network. First, our Eclair node will wait for bitcoind to start and then it will wait until bitcoind has mined some bitcoin into its wallet.
The Eclair container starts up and connects to the +bitcoind+ container over the Docker network. First, our Eclair node will wait for +bitcoind+ to start, and then it will wait until +bitcoind+ has mined some bitcoin into its wallet.
As we demonstrated previously, we can issue commands to our container in another terminal in order to extract information, open channels etc. The command that allows us to issue command-line instructions to the +eclair+ daemon is called +eclair-cli+. As before, in this container we have provided a useful alias to +eclair-cli+, called simply +cli+, which offers the necessary arguments and parameters. Using the +docker exec+ command in another terminal window we get the node info from Eclair:
As we demonstrated previously, we can issue commands to our container in another terminal to extract information, open channels, etc. The command that allows us to issue command-line instructions to the +eclair+ daemon is called +eclair-cli+. As before, in this container we have provided a useful alias to +eclair-cli+, called simply +cli+, which offers the necessary arguments and parameters. Using the +docker exec+ command in another terminal window we get the node info from Eclair:
We now have another Lightning node running on the +lnbook+ network and communicating with bitcoind. You can run any number and any combination of Lightning nodes on the same Lightning network. Any number of Eclair, LND, and c-lightning nodes can coexist. For example, to run a second Eclair node you would issue the +docker run+ command with a different container name as follows:
We now have another Lightning node running on the +lnbook+ network and communicating with +bitcoind+. You can run any number and any combination of Lightning nodes on the same Lightning network. Any number of Eclair, LND, and c-lightning nodes can coexist. For example, to run a second Eclair node you would issue the +docker run+ command with a different container name as follows:
[source,bash]
----
$ docker run -it --network lnbook --name eclair2 lnbook/eclair
----
In the above command we start another Eclair container named +eclair2+.
In the preceding command we start another Eclair container named +eclair2+.
In the next section we will also look at how to download and compile Eclair directly from the source code. This is an optional and advanced step that will teach you how to use the Scala and Java language build tools and allow you to make modifications to Eclair's source code. With this knowledge, you can write some code or fix some bugs.
@ -874,13 +861,11 @@ If you are not planning on diving into the source code or programming of a Light
==== Installing Eclair from Source Code
In this section we will build Eclair from scratch. Eclair is written in the Scala programming language which is compiled using the Java compiler. To run Eclair, we first need to install Java and its build tools. We will be following the instructions found in the BUILD.md document of the Eclair project:
In this section we will build Eclair from scratch. Eclair is written in the Scala programming language, which is compiled using the Java compiler. To run Eclair, we first need to install Java and its build tools. We will be following the instructions found in https://github.com/ACINQ/eclair/blob/master/BUILD.md[the BUILD.md document] of the Eclair project.
The required Java compiler is part of OpenJDK 11. We will also need a build framework called Maven, version 3.6.0 or above.
On a Debian/Ubuntu Linux system we can use the +apt+ command to install both OpenJDK11 and Maven as shown below:
On a Debian/Ubuntu Linux system we can use the +apt+ command to install both OpenJDK 11 and Maven as shown in the following:
[source,bash]
----
@ -904,7 +889,7 @@ We have OpenJDK 11.0.7 and Maven 3.6.1, so we're ready.
==== Copying the Eclair Source Code
The source code for Eclair is on Github. The +git clone+ command can create a local copy for us. Let's change to our home directory and run it there:
The source code for Eclair is on GitHub. The +git clone+ command can create a local copy for us. Let's change to our home directory and run it there:
Once +git clone+ finishes you will have a sub-directory +eclair+ containing the source code for the Eclair server.
Once +git clone+ finishes you will have a subdirectory +eclair+ containing the source code for the Eclair server.
==== Compiling the Eclair Source Code
@ -945,17 +930,15 @@ $ mvn package
After several minutes the build of the Eclair package should complete. However, the "package" action will also run tests, and some of these connect to the internet and could fail. If you want to skip tests, add +-DskipTests+ to the command.
Now, unzip and run the build package by following the instructions found here:
https://github.com/ACINQ/eclair#installing-eclair
Now, unzip and run the build package by following the https://github.com/ACINQ/eclair#installing-eclair[instructions for installing Eclair] from Github.
Congratulations! You have built Eclair from source and you are ready to code, test, fix bugs, and contribute to this project!
=== Building a Complete Network of Diverse Lightning Nodes
Our final example, presented in this section, will bring together all the various containers we've built to form a Lightning network made of diverse (LND, c-lightning, Eclair) node implementations. We'll compose the network by connecting the nodes together and opening channels from one node to another. As the final step, we'll route a payment across these channels!
Our final example, presented in this section, will bring together all the various containers we've built to form a Lightning Network made of diverse (LND, c-lightning, Eclair) node implementations. We'll compose the network by connecting the nodes together and opening channels from one node to another. As the final step, we'll route a payment across these channels!
In this example, we will build a demonstration Lightning network made of four Lightning nodes named Alice, Bob, Chan, and Dina. We will connect Alice to Bob, Bob to Chan, and Chan to Dina. This is shown in <<alice_bob_chan_dina_network_demo>>.
In this example, we will build a demonstration Lightning Network made of four Lightning nodes named Alice, Bob, Chan, and Dina. We will connect Alice to Bob, Bob to Chan, and Chan to Dina. This is shown in <<alice_bob_chan_dina_network_demo>>.
[[alice_bob_chan_dina_network_demo]]
.A small demonstration network of four nodes
@ -967,9 +950,7 @@ Finally, we will have Dina create an invoice and have Alice pay that invoice. Si
To make this example work, we will be using a _container orchestration_ tool that is available as a command called +docker-compose+. This command allows us to specify an application composed of several containers and run the application by launching all the cooperating containers together.
First, let's install +docker-compose+. The instructions depend on your operating system and can be found here:
https://docs.docker.com/compose/install/
First, let's install +docker-compose+. The https://docs.docker.com/compose/install/[instructions] depend on your operating system and can be found here:
Once you have completed installation, you can verify your installation by running docker-compose like this:
@ -981,11 +962,11 @@ docker-compose version 1.21.0, build unknown
----
The most common +docker-compose+ commands we will use are +up+ and +down+, e.g. +docker-compose up+.
The most common +docker-compose+ commands we will use are +up+ and +down+, e.g., +docker-compose up+.
==== Docker-Compose Configuration
The configuration file for +docker-compose+ is found in the +code/docker+ directory and is named +docker-compose.yml+. It contains a specification for a network and each of the four containers. The top looks like this:
The configuration file for +docker-compose+ is found in the _code/docker_ directory and is named _docker-compose.yml_. It contains a specification for a network and each of the four containers. The top looks like this:
----
version: "3.3"
@ -1009,7 +990,7 @@ services:
container_name: Alice
----
The fragment above defines a network called +lnnet+ and a container called +bitcoind+ which will attach to the +lnnet+ network. The container is the same one we built at the beginning of this chapter. We expose three of the container's ports allowing us to send commands to it and monitor blocks and transactions. Next, the configuration specifies an LND container called "Alice". Further down you will also see specifications for containers called "Bob" (c-lightning), "Chan" (Eclair) and "Dina" (LND again).
The preceding fragment defines a network called +lnnet+ and a container called +bitcoind+ which will attach to the +lnnet+ network. The container is the same one we built at the beginning of this chapter. We expose three of the container's ports, allowing us to send commands to it and monitor blocks and transactions. Next, the configuration specifies an LND container called "Alice." Further down you will also see specifications for containers called "Bob" (c-lightning), "Chan" (Eclair), and "Dina" (LND again).
Since all these diverse implementations follow the Basis of Lightning Technologies (BOLT) specification and have been extensively tested for interoperability, they have no difficulty working together to build a Lightning network.
@ -1057,7 +1038,7 @@ Bob | Starting c-lightning...
----
Following the startup, you will see a whole stream of logfiles as each of the nodes starts up and reports its progress. It may look quite jumbled on your screen, but each output line is prefixed by the container name as seen above. If you wanted to watch the logs from only one container, you can do so in another terminal window by using the +docker-compose logs+ command with the +f+ (_follow_) flag and the specific container name:
Following the startup, you will see a whole stream of logfiles as each of the nodes starts up and reports its progress. It may look quite jumbled on your screen, but each output line is prefixed by the container name as seen previously. If you wanted to watch the logs from only one container, you can do so in another terminal window by using the +docker-compose logs+ command with the +f+ (_follow_) flag and the specific container name:
[source,bash]
----
@ -1068,7 +1049,7 @@ $ docker-compose logs -f Alice
Our Lightning network should now be running. As we saw in the previous sections of this chapter, we can issue commands to a running Docker container with the +docker exec+ command. Regardless of whether we started the container with +docker run+ or started a bunch of them with +docker-compose up+, we can still access containers individually using the Docker commands.
The payment demo is contained in a Bash shell script called +run-payment-demo.sh+. To run this demo you must have the Bash shell installed on your computer. Most Linux and Unix-like systems (e.g. MacOS) have +bash+ pre-installed. Windows users can install the _Windows Subsystem for Linux_ and use a Linux distribution like _Ubuntu_ to get a native +bash+ command on their computer.
The payment demo is contained in a Bash shell script called +run-payment-demo.sh+. To run this demo you must have the Bash shell installed on your computer. Most Linux and Unix-like systems (e.g., macOS) have +bash+ preinstalled. Windows users can install the Windows Subsystem for Linux and use a Linux distribution like Ubuntu to get a native +bash+ command on their computer.
Let's run the script to see its effect and then we will look at how it works internally. We use +bash+ to run it as a command:
@ -1117,7 +1098,7 @@ Successful payment!
----
As you can see from the output, the script first gets the node IDs (public keys) for each of the four nodes. Then, it connects the nodes and sets up a 1,000,000 satoshi channel from each node to the next in the network. Finally, it issues an invoice for 10k satoshis from Dina's node and pays the invoice from Alice's node.
As you can see from the output, the script first gets the node IDs (public keys) for each of the four nodes. Then, it connects the nodes and sets up a 1,000,000 satoshi channel from each node to the next in the network. Finally, it issues an invoice for 10,000 satoshis from Dina's node and pays the invoice from Alice's node.
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@ -1126,7 +1107,7 @@ If the script fails, you can try running it again from the beginning. Or you can
There is a lot to review in that script, but as you gain understanding of the underlying technology, more and more of that information will become clear. You are invited to revisit this example later.
Of course, you can do a lot more with this test network than a 3-channel, 4-node payment. Here are some ideas for your experiments:
Of course, you can do a lot more with this test network than a three-channel, four-node payment. Here are some ideas for your experiments:
* Create a more complex network by launching many more nodes of different types. Edit the +docker-compose.yml+ file and copy sections, renaming containers as needed.
kristen@oreilly.com
3 years ago