How to setup Sentry Node

The sentry node setup is a way to secure your validator node by hiding it behind a set of so-called sentry fullnodes. The validator node is located in a private network and will only have contact with the sentry nodes. This tutorial is a brief description of how to achieve this.

  1. Create machines for N sentry nodes and 1 validator node
  2. Create private network for senty nodes' machines and validator's machine (e.g. you can use WireGuard and easy-wg-quick to quick setup)
  3. Setup firewall on validator node to accept connections only from sentry nodes' machines (e.g. https://aws.amazon.com/network-firewall)
  4. Setup sentry node(s):
  • Adapt docker-compose.yaml:
version: "3"

services:
  testnet-sentrynode:
    image: $QCLIENT_IMAGE
    entrypoint: [
      "geth",
      "--datadir=/data",
      "--bootnodes=$BOOTNODE_URI",
      "--port=$EXT_PORT",
      "--syncmode=full",
      "--verbosity=3",
      "--testnet",
      "--miner.gasprice=50000000000",
      "--txpool.pricelimit=47619047619",
      "--http.addr=0.0.0.0",
      "--http.corsdomain=*",
      "--http.api=net,web3,eth"
    ]
    volumes:
      - ./additional:/data/additional
      - testnet-sentrynode-data:/data
    ports:
      - $EXT_PORT:$EXT_PORT/tcp
      - $EXT_PORT:$EXT_PORT/udp
    restart: unless-stopped

volumes:
  testnet-sentrynode-data:
  • Adapt .env:
QCLIENT_IMAGE=qblockchain/q-client:1.2.2
BOOTNODE_URI=enode://$BOOTNODE_ENODE_PUBLIC_KEY@$BOOTNODE_IP:30301
EXT_PORT=30303
  1. Run node
$ docker-compose up -d
  1. Get admin.nodeInfo.enode from nodes' JS console and copy enode URI
$ docker-compose exec testnet-sentrynode geth attach data/geth.ipc

$ admin.nodeInfo.enode
  1. Setup validator node:
  • Adapt docker-compose.yaml:
version: "3"

services:
  testnet-validator-node:
    image: $QCLIENT_IMAGE
    entrypoint: [
      "geth",
      "--datadir=/data",
      "--bootnodes=$SENTRY",
      "--syncmode=full",
      "--verbosity=3",
      "--testnet",
      "--miner.gasprice=50000000000",
      "--txpool.pricelimit=47619047619",  
      "--mine",
      "--unlock=$VALIDATOR_ADDRESS",
      "--password=/data/keystore/pwd.txt",
      "--nodiscover",
      "--netrestrict $MASK"
    ]   
    volumes:
      - ./keystore:/data/keystore
      - ./additional:/data/additional
      - testnet-validator-node-data:/data
    restart: unless-stopped

volumes:
  testnet-validator-node-data:
  • Adapt .env:
QCLIENT_IMAGE=qblockchain/q-client:1.2.2
VALIDATOR_ADDRESS=0000000000000000000000000000000000000000
SENTRY=uri1,uri2,uri3
MASK=10.xxx.xxx.0/24

10.xxx.xxx.0/24 is the network mask of your private network (note: it can be not only in 10.0.0.0 range).

  1. Add sentries' uris to /data/geth/static-nodes.json
[
    "uri1",
    "uri2",
    "uri3",
    ...
]

uri1,uri2,uri3 are the enode uris of your sentry nodes. Please provide all uris because peer discovery discovery is disabled!

  1. Start validator
$ docker-compose up -d
  1. Wait for sync and check mining is working

Notice: if ping is huge your blocks can don't reach to blockchain