Get Started

Introduction

The core of the NKN network consists of many connected nodes distributed globally. Every node is only connected to and aware of a few other nodes called neighbors. Packets can be transmitted from any node to any other node in an efficient and verifiable route. Data can be sent to any clients without public or static IP address using their permanent NKN address with end-to-end encryption. The network stack of NKN network is open source at another repo called nnet that can be used to build other decentralized/distributed systems.

The relay workload can be verified using our Proof of Relay (PoR) algorithm. A small and fixed portion of the packets will be randomly selected as proof. The random selection can be verified and cannot be predicted or controlled. Proof will be sent to other nodes for payment and rewards.

A node in our network is both relayer and consensus participant. Consensus among massive nodes can be reached efficiently by only communicating with neighbors using our consensus algorithm based on Cellular Automata. Consensus is reached for every block to prevent fork.

More details can be found in our wiki.

Technical Highlights

Deployment

Q: I want to run this node, but have no idea about programming or terminal. What should I do?

A: Easiest for you will be to follow docker instructions below. Docker will take care of quite a lot of things for you. If you are asked to run or issue command (usually formatted like this:)

$ cd change/active/directory/to/this/one

open a terminal (or cmd on windows - start -> run/search -> cmd.exe) and write the command there. (Without the $ symbol)

Use pre-built binaries

You need to download a few things:

  1. nknd and nknc binaries from github releases. You just need the one matches your architecture.
  2. A config file corresponding to the network you want to connect to. For mainnet you need to download config.mainnet.json and rename it to config.json

Then you need to put nknd, nknc, and config.json in the same directory.

Now you can see configuration for how to configure and run a node.

Use pre-built Docker image

Prerequirement: Have working docker software installed. For help with that visit official docker docs

We host latest Docker image (the same as you build with docker) on our official Docker Hub account. You can get it by

$ docker pull nknorg/nkn

Now you can see configuration for how to configure and run a node.

Building using Docker

Prerequirement: Have working docker software installed. For help with that visit official docker docs

Build and tag Docker image

$ docker build -t nknorg/nkn .

This command should be run once every time you update the code base.

When starting the container, a directory with configuration files containing config.json (see configuration) and wallet.json (if exists) should be mapped to /nkn/data directory in the container. This directory will also be used for blockhain data and logs storage by default. The path of config file, wallet file, database directory and log directory can be specified by passing arguments to nknd, run nknd --help for more information.

Building from source

To build from source, you need a properly configured Go environment (Go 1.11.4+, see Go Official Installation Documentation for more details).

$ git clone https://github.com/nknorg/nkn.git

Build the source code with make

$ make

After building is successful, you should see two executables:

  • nknd: the nkn node program
  • nknc: command line tool for nkn node control

Now you can see configuration for how to configure and run a node.

You can also build binaries for other architectures by executing make all. The resulting binaries are stored in build directory.

Configuration

When starting a NKN node (i.e. running nknd), it will reads two files: config.json and wallet.json. By default nknd assumes these two files are located in the current working directory, but it can be changed by passing --config and --wallet arguments to nknd.

a directory with configuration files containing config.json (see configuration) and wallet.json (if exists) should be mapped to /nkn/data directory in the container. The path of config file, wallet file, database directory and log directory can be specified by passing arguments to nknd, run nknd --help for more information.

We provide a few sample config.json:

  • config.mainnet.json: join the mainnet
  • config.testnet.json: join the testnet
  • config.local.json: create and join a private chain on your localhost

You can copy the one you want to config.json or write your own.

Before starting the node, you need to create a new wallet first. Wallet information will be saved at wallet.json and it's encrypted with the password you provided when creating the wallet. So please make sure you pick a strong password and remember it!

$ ./nknc wallet -c
Password:
Re-enter Password:
Address                                Public Key
-------                                ----------
NKNRQxosmUixL8bvLAS5G79m1XNx3YqPsFPW   35db285ea2f91499164cd3e19203ab5e525df6216d1eba3ac6bcef00503407ce

If you are using Docker, it should be docker run -it -v $PWD:/nkn/data nknorg/nkn nknc wallet -c instead, assuming you want to store the wallet.json in your current working directory. If you want it to be saved to another directory, you need to change $PWD to that directory.

[IMPORTANT] Each node needs to use a unique wallet. If you use share wallet among multiple nodes, only one of them will be able to join the network!

After nknd starts, it will creates two directories: ChainDB to store blockchain data, and Log to store logs. By default nknd will creates these directories in the current working directory, but it can be changed by passing --chaindb and --log arguments to nknd.

Now you can join the mainnet, join the testnet or create a private chain.

Join the MainNet

**[IMPORTANT] Currently, in order to join the MainNet, you need to have a public IP address, or set up port forwarding on your router properly so that other people can establish connection to you.

If you have done the previous steps correctly (config.json, create wallet, public IP or port forwarding), joining the MainNet is as simple as running:

$ ./nknd

If you are using Docker then you should run the following command instead:

$ docker run -p 30001-30003:30001-30003 -v $PWD:/nkn/data --name nkn --rm -it nknorg/nkn nknd

If you get an error saying docker: Error response from daemon: Conflict. The container name "/nkn" is already in use by container ..., you should run docker rm nkn first to remove the old container.

If everything goes well, you should be part of the MainNet after a few minutes! You can query your wallet balance (which includes the NKN token you've mined) by:

$ ./nknc wallet -l balance

or if you are using Docker:

$ docker exec -it nkn nknc wallet -l balance

If there is a problem, you may want to check if any of the previous steps went wrong. If the problem still persists, create an issue or ask us in our Discord group.

[Recommended] Using BeneficiaryAddr

By default, token mined by your node will be sent to the wallet your node is using, which is NOT as safe as you might think. The recommended way is to use another cold wallet (that is saved and backed up well) to store your token. You can use your code wallet address as BeneficiaryAddr in config.json such that token mined by your node will be sent directly to that beneficiary address. This is safer and more convenient because: 1. even if your node is hacked, or your node wallet is leaked, you will not lose any token; 2. if you run multiple nodes, it's the only way that all their mining rewards will go to the same address.

NAT traversal and port forwarding

Most likely your node is behind a router and does not have a public IP address. By default, nknd will try to detect if your router supports UPnP or NAT-PMP protocol, and if success, it will try to set up port forwarding automatically. You can add --no-nat flag when starting nknd OR add "NAT": false in config.json to disable automatic port forwarding. If your router does not support such protocol, you have to setup port forwarding on your router for port 30001 as well as all other ports specified in config.json (30001-30003 by default), otherwise other nodes cannot establish connections to you and you will NOT be able to mine token even though your node can still run and sync blocks.

When setting up port forwarding, public port needs to be the same as private port mapped to your node. For example, you should map port 30001 on your router's public IP address to port 30001 on your node's internal IP address.

The specific steps to setup port forwarding depends on your router. But in general, you need to log in to the admin interface of your router (typically in a web browser), then navigate to the port forwarding section, and create several mappings, one for each port. One of the easiest way to find out how to setup port forwarding on your router is to search "how to setup port forwarding" + your router model or name online.

Join the TestNet

Joining the TestNet is the same as joining MainNet, except for using config.testnet.json as your config file instead of config.mainnet.json. Note that TestNet token is for testing purpose only (thus do not have value), and may be cleared at any time when TestNet upgrades.

Contributing

Can I submit a bug, suggestion or feature request?

Yes. Please open an issue for that.

Can I contribute patches to NKN project?

Yes, we appreciate your help! To make contributions, please fork the repo, push your changes to the forked repo with signed-off commits, and open a pull request here.

Please follow our Golang Style Guide for coding style.

Please sign off your commit. This means adding a line "Signed-off-by: Name " at the end of each commit, indicating that you wrote the code and have the right to pass it on as an open source patch. This can be done automatically by adding -s when committing:

git commit -s

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