Bitcoin Mirror

Link Bluewallet to LndHub on your own VPS Lightning node tutorial

Massimo Cortesi -

With the Lightning Network taking off and proving the effectiveness of a second layer scaling solution to Bitcoin, it becomes more urgent to provide wallets with natural interfaces and straightforward onboarding processes.
In this phase, a team that is pushing in what, according to me, is the right direction is BlueWallet. These guys made an iOS/Android wallet, BlueWallet, that is pretty easy to use and is already on both the leading mobile stores.
At first sight, you could think this is another custodial solution that doesn't deserve our attention cause of the vision, but wait: you can use it connected to their node, or you can link it to another one, and they also provide LndHub, the software that allows you to have different lightning's accounts on a single node.
Both BlueWallet and LndHub are open-source, the team encourages people to run it instead of trusting their node, so this is what we are doing today.
Let's start. Your family members deserve a Lightning wallet connected to your safe family node, even if they don't know what you're talking about.

To avoid rewriting things already well explained in other tutorials, I leave here a link to set up your Bitcoin&Lightning node on Ubuntu 16.04, if you already have one you can jump to Step 1.
You can follow this or other guides as long as LND is the implementation of choice for Lightning, we will apply the necessary changes to configurations files in the next steps. If you are starting from scratch, I suggest to execute this on a VPS, for example a Digital Ocean's droplet.

Step 1: Install Redis

LndHub uses Redis as database, install it with

$ sudo apt update
$ sudo apt install redis-server

and edit two important settings in

$ sudo nano /etc/redis/redis.conf

changing the line about supervised from supervised no to supervised systemd

# If you run Redis from upstart or systemd, Redis can interact with your
# supervision tree. Options:
#   supervised no      - no supervision interaction
#   supervised upstart - signal upstart by putting Redis into SIGSTOP mode
#   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
#   supervised auto    - detect upstart or systemd method based on
#                        UPSTART_JOB or NOTIFY_SOCKET environment variables
# Note: these supervision methods only signal "process is ready."
#       They do not enable continuous liveness pings back to your supervisor.
supervised systemd

and the line appendonly no to appendonly yes to enable disk persistance.

# AOF and RDB persistence can be enabled at the same time without problems.
# If the AOF is enabled on startup Redis will load the AOF, that is the file
# with the better durability guarantees.
#
# Please check http://redis.io/topics/persistence for more information.

appendonly yes

# The name of the append only file (default: "appendonly.aof")

appendfilename "appendonly.aof"

# The fsync() call tells the Operating System to actually write data on disk

Step 2: Redis autostart

Setup Redis to start automatically after a system restart. Open the file

$ sudo nano /etc/systemd/system/redis.service

and paste the following script inside.

[Unit]
Description=Redis In-Memory Data Store
After=network.target

[Service]
User=redis
Group=redis
ExecStart=/usr/bin/redis-server /etc/redis/redis.conf
ExecStop=/usr/bin/redis-cli shutdown
Restart=always

[Install]
WantedBy=multi-user.target

Now start and enable it with systemctl.

$ sudo systemctl start redis
$ sudo systemctl enable redis

Step 3: Bitcoin&LND configuration files

Since bitcoin.conf and lnd.conf are often topic of discussion, here I paste my files that are currently working with Bitcoin v0.17.1 and LND v0.5.1-beta, except for passwords of course.

$ sudo nano .bitcoin/bitcoin.conf

server=1
txindex=1
daemon=1
externalip=104.248.248.9
maxconnections=10
rpcuser=user
rpcpassword=password
minrelaytxfee=0.00000000
incrementalrelayfee=0.00000010
zmqpubrawblock=tcp://127.0.0.1:28332
zmqpubrawtx=tcp://127.0.0.1:28333
rpcport=8332

$ sudo nano .lnd/lnd.conf

[Application Options]
; set external IP if not using NAT
externalip=104.248.248.9
; set node alias (seen in explorers)
alias=HIVENLABSLN1
restlisten=localhost:8080

[Bitcoin]
bitcoin.active=1
bitcoin.mainnet=1
bitcoin.node=bitcoind

[Bitcoind]
bitcoind.rpcuser=user
bitcoind.rpcpass=password
bitcoind.zmqpubrawblock=tcp://127.0.0.1:28332
bitcoind.zmqpubrawtx=tcp://127.0.0.1:28333

Note: external IP field is to be changed according to your VPS IP.

Step 4: Download and configure LndHub

You are now ready to get and install LndHub, start copying the github repository with

$ git clone https://github.com/BlueWallet/LndHub

and copy admin.macaroon and tls.cert in root folder of LndHub.

$ cp .lnd/data/chain/bitcoin/mainnet/admin.macaroon LndHub/
$ cp .lnd/tls.cert LndHub/

Now you need to set the config file of LndHub. As for bitcoind and lnd I leave you here my version.

$ sudo nano LndHub/config.js

let config = {
  bitcoind: {
    rpc: 'http://user:password@127.0.0.1:8332',
  },
  redis: {
    port: 6379,
    host: '127.0.0.1',
    family: 4,
    db: 0,
  },
  lnd: {
    url: '127.0.0.1:10009',
  },
};

if (process.env.CONFIG) {
  console.log('using config from env');
  config = JSON.parse(process.env.CONFIG);
}

module.exports = config;

Step 5: Install LndHub

Node is required to install and run LndHub, install it with the following command.

$ sudo apt install nodejs npm

Enter the LndHub folder and install node modules.

$ cd LndHub
$ npm install

Compile babeljs

$ npm install -g babel-cli
$ mkdir build
$ babel ./ --out-dir ./build --copy-files --ignore node_modules

and, finally, run it.

$ node build/index.js

Step 6: LndHub autostart

Setup LndHub to start automatically after a system restart. Open the file

$ sudo nano /etc/systemd/system/lndhub.service

and paste the following script inside.

[Unit]
Description=LndHub Wrapper for Lightning Daemon
Wants=lnd.service
After=lnd.service

[Service]
WorkingDirectory=/LndHub
ExecStart=/usr/bin/node build/index.js

Type=simple
KillMode=process
LimitNOFILE=128000
TimeoutSec=240
Restart=always
RestartSec=60

[Install]
WantedBy=multi-user.target

Now start and enable it with systemctl.

$ sudo systemctl enable lndhub
$ sudo systemctl start lndhub

You should now see the LndHub default page at this address: http://vps-ip-address:3000/

Step 7: Link Bluewallet to your node

Open the Bluewallet app on your smartphone, go to settings (top-right corner) -> Lightning Settings and add your node URL http://vps-ip-address:3000/.
There is no confirmation message when you click Save at the moment, v3.7.2 on iOS, so don't worry if you don't see any feedback. The first test you can do is create a new Lightning wallet and generate an invoice, and if no error is returned, it's all correctly configured.
Your bank is born, let's take a moment to think about what you achieved here: you can now pay in BTC from your smartphone instantly with Lightning, everywhere in the world, and you can let somebody who trusts you join your node and create their account linked with your hub just downloading an app.