Aura Validator

This article will lead you through docker-compose setup of Nethermind Aura Validator (xDai chain in this example). Same result can be obtained by Downloading & Running Nethermind package or by Building Nethermind from the source code.

If you chose not to use docker-compose, you can skip docker-compose related sections and read about config file and private key configuration only.

Prerequisites

Clock synchronization

You system clock needs to be synchronized otherwise you might encounter skipping block sealing. By default stepDuration is configured to 5s.

Verify if your system clock is synchronized, type timedatectl status and you should see similar output:

Local time: Tue 2020-06-30 17:16:19 UTC
Universal time: Tue 2020-06-30 17:16:19 UTC
RTC time: Tue 2020-06-30 17:16:19
Time zone: Etc/UTC (UTC, +0000)
System clock synchronized: yes
systemd-timesyncd.service active: yes
RTC in local TZ: no

If System clock synchronized displays yes you are all set, otherwise you may need to either:

Docker-compose file sample

docker-compose.yml

version: '3.5'
services:
  nethermind-validator:
    image: nethermind/nethermind
    container_name: nethermind-validator
    restart: unless-stopped
    ports:
      - 8545:8545
      - 30303:30303
    network_mode: host
    environment:
      - NETHERMIND_CONFIG=xdai
    volumes:
      - ${PWD}/nethermind_db:/nethermind/nethermind_db
      - ${PWD}/keystore:/nethermind/keystore
      - ${PWD}/logs:/nethermind/logs
      - ${PWD}/xdai.cfg:/nethermind/configs/xdai.cfg 
      - ${PWD}/NLog.config:/nethermind/NLog.config
      - ${PWD}/static-nodes.json:/nethermind/Data/static-nodes.json
volumes:
  nethermind_db:
    driver: local
    name: nethermind_db
  keystore:
    driver: local
    name: keystore
  logs:
    driver: local
    name: logs

Configure Nethermind node via environment variables or use local config file and map it to the one, existing inside container (xdai.cfg file in above example).

Make sure that nethermind_db, keystore(logs - optional ) are mapped, otherwise you might lose database or keys

Mining Private key

Make sure that the filename contains key's public address otherwise it won't be recognized by Nethermind Client as a keyfile. Correct naming of a keyfile: key-a5237f7f43cc46cba43ac212dabd0c45e3e3050a

The keyfile should be then stored inside keystore volume.

Config file

xdai.cfg

{
  "Init": {
    "WebSocketsEnabled": false,
    "StoreReceipts": true,
    "IsMining": true,
    "ChainSpecPath": "chainspec/xdai.json",
    "GenesisHash": "0x4f1dd23188aab3a76b463e4af801b52b1248ef073c648cbdc4c9333d3da79756",
    "BaseDbPath": "nethermind_db/xdai",
    "LogFileName": "xdai.logs.txt",
    "MemoryHint": 3000000000,
    "StaticNodesPath": "Data/static-nodes.json"
  },
  "Network": {
    "DiscoveryPort": 30303,
    "P2PPort": 30303
  },
  "JsonRpc": {
    "Enabled": false,
    "Host": "127.0.0.1",
    "Port": 8545,
    "WebSocketsPort": 8546
  },
  "Db": {
    "HeadersDbCacheIndexAndFilterBlocks": false,
    "BlocksDbCacheIndexAndFilterBlocks": false,
    "ReceiptsDbCacheIndexAndFilterBlocks": false,
    "BlockInfosDbCacheIndexAndFilterBlocks": false
  },
  "Sync": {
    "FastSync": true,
    "PivotNumber": 10410000,
    "PivotHash": "0x806f498fdde010f25bd3beb18e6f8a9c9450752f8c0e27da2cd2465ff184628c",
    "PivotTotalDifficulty": "3542339439646969404653729663364707080928280566",
    "FastBlocks": true,
    "UseGethLimitsInFastBlocks": false,
    "FastSyncCatchUpHeightDelta": 10000000000
  },
  "EthStats": {
    "Enabled": false,
    "Server": "ws://localhost:3000/api",
    "Name": "Nethermind xDai",
    "Secret": "secret",
    "Contact": "[email protected]"
  },
  "Metrics": {
    "NodeName": "Nethermind xDai",
    "Enabled": false,
    "PushGatewayUrl": "http://localhost:9091/metrics",
    "IntervalSeconds": 5
  },
  "KeyStore": {
    "PasswordFiles": ["keystore/password.file"],
    "UnlockAccounts": ["0x..."],
    "BlockAuthorAccount": "0x..." 
  },
  "Aura": {
    "ForceSealing": true
  },
  "Bloom": {
    "IndexLevelBucketSizes": [
      16,
      16,
      16
    ]
  }
}

Running Validator node

To check the logs and verify if it is sealing blocks as expected (look for the Sealed block log).