Band Protocol

Band Protocol is a cross-chain data oracle platform that aggregates and connects real-world data and APIs to smart contracts.

Official: 4 CPU x 16 GB RAM x 550 GB SSD - Ubuntu 20.04.

Set Up variables

# Chain ID of Laozi Mainnet
export CHAIN_ID=laozi-mainnet

# Wallet name to be used as validator's account, please change this into your name (no whitespace).
export WALLET_NAME=<YOUR_WALLET_NAME>

# Name of your validator node, please change this into your name.
export MONIKER=<YOUR_MONIKER>

# URL of genesis file for Laozi Mainnet
export GENESIS_FILE_URL=https://raw.githubusercontent.com/bandprotocol/launch/master/laozi-mainnet/genesis.json 

# Data sources/oracle scripts files
export BIN_FILES_URL=https://raw.githubusercontent.com/bandprotocol/launch/master/laozi-mainnet/files.tar.gz

Step 1.1: Install Prerequisites

# install required tools
sudo apt-get update && sudo apt-get upgrade -y && \sudo apt-get install -y build-essential curl wget

• Go

# Install Go
sudo wget -q -O - https://git.io/vQhTU | bash
source /$HOME/.bashrc

Step 1.2: Clone & Install Bandchain Laozi

# Clone Bandchain Laozi 
git clone https://github.com/bandprotocol/chain
cd chain && git checkout v2.3.3

# Install binaries
make install

Step 1.3: Initialize the Bandchain and download genesis file

cd $HOME

# Initialize configuration and genesis state
bandd init --chain-id $CHAIN_ID "$MONIKER"

# Replace genesis file with our genesis file
wget $GENESIS_FILE_URL -O $HOME/.band/config/genesis.json

# Download data sources / oracle scripts files, and store in $HOME/.band/files
wget -qO- $BIN_FILES_URL | tar xvz -C $HOME/.band/

# Create new account
bandd keys add $WALLET_NAME

Step 1.4: Setup seeds or persistence peers of your node to the network.

seeds="[email protected]:26656,[email protected]:26656"

peers="[email protected]:26656,[email protected]:26656,[email protected]:58856,[email protected]:41656,[email protected]:26656,[email protected]:26656,[email protected]:26656,[email protected]:26656,[email protected]:26656,[email protected]:26656,[email protected]:26656,[email protected]:30656,[email protected]:30656,[email protected]:30656,[email protected]:26656"

sed -i.bak -e "s/^seeds *=.*/seeds = \"$seeds\"/; s/^persistent_peers *=.*/persistent_peers = \"$peers\"/" $HOME/.band/config/config.toml

Step 1.5: Create service

# Write bandd service file to /etc/systemd/system/bandd.service
export USERNAME=$(whoami)

sudo -E bash -c 'cat << EOF > /etc/systemd/system/bandd.service
[Unit]
Description=BandChain Node Daemon
After=network-online.target

[Service]
User=$USERNAME
ExecStart=/home/$USERNAME/go/bin/bandd start
Restart=always
RestartSec=3
LimitNOFILE=4096

[Install]
WantedBy=multi-user.target
EOF'

Based on design, validator need to send a transaction to submit reports based on certain oracle requests. The validator should send transactions to submit reports within specified timeframe. However, the method is quite tedious. Therefore, we have develop an application called Yoda, which is a bot application that help validator automatically listen new oracle requests on Bandchain, execute data sources, and submit report to Bandchain, so validators don't have to send the transactions manually.

Step 2.1: Prerequisites

Before setting up Yoda, Lambda function executor need to be setup to execute data sources. If this step has not been done yet, please follow the instructions on following pages (select either one of these methods):

• AWS Lambda Function
• Google Cloud Function

Then, check Yoda version that we have compiled. It should be v2.3.2.

yoda version
# v2.3.2

Step 2.2: Configure Yoda

Firstly, configure Yoda's basic configurations

rm -rf ~/.yoda # clear old config if exist
yoda config chain-id $CHAIN_ID
yoda config node http://localhost:26657
yoda config broadcast-timeout "5m"
yoda config rpc-poll-interval "1s"
yoda config max-try 5
yoda config validator $(bandd keys show $WALLET_NAME -a --bech val)

Secondly, add multiple reporter accounts to allow Yoda submitting transactions concurrently.

yoda keys add REPORTER_1
yoda keys add REPORTER_2
yoda keys add REPORTER_3
yoda keys add REPORTER_4
yoda keys add REPORTER_5

Thirdly, config Lambda Executor endpoint

export EXECUTOR_URL=<YOUR_EXECUTOR_URL>
yoda config executor "rest:${EXECUTOR_URL}?timeout=10s"

Step 2.3: Start Yoda

We also do recommend to use systemctl the same as bandd.

# Write yoda service to /etc/systemd/system/yoda.service
export USERNAME=$(whoami)
sudo -E bash -c 'cat << EOF > /etc/systemd/system/yoda.service
[Unit]
Description=Yoda Daemon
After=network-online.target

[Service]
User=$USERNAME
ExecStart=/home/$USERNAME/go/bin/yoda run
Restart=always
RestartSec=3
LimitNOFILE=4096

[Install]
WantedBy=multi-user.target
EOF'

To register both bandd and yoda services, run the following commands.

# Register bandd daemon to systemctl
sudo systemctl enable bandd
# Register yoda to systemctl
sudo systemctl enable yoda

Then start bandd service which also automatically initiates yoda

# Start bandd daemon
sudo systemctl start bandd

Once bandd service has been started, logs can be queried by running journalctl -u bandd.service -f command. You will see your node beginning to sync.

After yoda service has been started, logs can be queried by running journalctl -u yoda.service -f command. Log should be similar to the following log example below. Once verified, you can stop tailing the log by typing Control-C.

... systemd[...]: Started Yoda Daemon.
... yoda[...]: I[...] ⭐  Creating HTTP client with node URI: tcp://localhost:26657
... yoda[...]: I[...] 🚀  Starting WebSocket subscriber
... yoda[...]: I[...] 👂  Subscribing to events with query: tm.event = 'Tx'...

Step 2.4: Wait for latest blocks to be synced

This is an important step. We should wait for newly started Bandchain node to sync their blocks until the latest block is reached. The latest block can be checked on this Block Explorer.

This step provides procedures to register the node as a validator.

Step 3.1: Fund the Validator Account

bandd keys show $WALLET_NAME

Then fund tokens into this account ready for staking.

Step 3.2: Stake Tokens with the Validator Account

bandd tx staking create-validator \
    --amount 3000000uband \
    --commission-max-change-rate 0.01 \
    --commission-max-rate 0.2 \
    --commission-rate 0.1 \
    --from $WALLET_NAME \
    --min-self-delegation 1 \
    --moniker "$MONIKER" \
    --pubkey $(bandd tendermint show-validator) \
    --chain-id $CHAIN_ID

After became a validator, the validator node will be shown on Block Explorer here.

Step 3.3: Register Reporters and Become Oracle Provider

Now, Yoda have multiple reporters. In order to register the reporters to be owned by the validator, the following commands should be run.

Firstly, reporter accounts must be create on Bandchain by supplying some small amount of BAND tokens.

# Send 1uband from a wallet to each reporter.
bandd tx multi-send 1uband $(yoda keys list -a) \
  --from $WALLET_NAME \
  --chain-id $CHAIN_ID

Secondly, register reporters to the validator, so that oracle requests for validator can be assigned to the reporters.

bandd tx oracle add-reporters $(yoda keys list -a) \
  --from $WALLET_NAME \
  --chain-id $CHAIN_ID

Finally, activate the validator to become an oracle provider

bandd tx oracle activate \
  --from $WALLET_NAME \
  --chain-id $CHAIN_ID

If all procedures are successful, then oracle provider status for the validator should be active.

bandd query oracle validator $(bandd keys show -a $WALLET_NAME --bech val)

# {
#   "is_active": true,
#   "since": ...
# }

And now you have become a validator on Bandchain Laozi mainnet. Happy staking