Function for getting the delta between your lastBlockCount and the one from the Shelley Explorer (add to .bash_profile)

delta2.sh

# Note that it seems like the explorer is load balanced across multiple nodes, as sometimes a call will show that
# you are ahead by a few blocks, but an immediate subsequent call will show you are in sync.
# Add this to your .bash_profile

function delta2() {
    # Kudos to @pheelLikeWater for original version of this!
    lastBlockHash=`stats | head -n 6 | tail -n 1 | awk '{print $2}'`
    lastBlockCount=`stats | head -n 7 | tail -n 1 | awk '{print $2}' | tr -d \"`
    shelleyExplorerJson=`curl -X POST -H "Content-Type: application/json" --data '{"query":" query {      allBlocks (last: 1) {          pageInfo {    hasNextPage    hasPreviousPage    startCursor    endCursor  }        totalCount        edges {          node {              id  date {    slot    epoch {        id  firstBlock {    id  }  lastBlock {    id  }  totalBlocks    }  }  transactions {    totalCount    edges {      node {          id  block {    id    date {      slot      epoch {          id  firstBlock {    id  }  lastBlock {    id  }  totalBlocks      }    }    leader {      __typename      ... on Pool {          id  blocks {    totalCount  }  registration {    startValidity    managementThreshold    owners    operators    rewards {      fixed      ratio {        numerator        denominator      }      maxLimit    }    rewardAccount {      id    }  }      }    }  }  inputs {    amount    address {      id    }  }  outputs {    amount    address {      id    }  }      }      cursor    }  }  previousBlock {    id  }  chainLength  leader {    __typename    ... on Pool {        id  blocks {    totalCount  }  registration {    startValidity    managementThreshold    owners    operators    rewards {      fixed      ratio {        numerator        denominator      }      maxLimit    }    rewardAccount {      id    }  }    }  }          }          cursor        }      }    } "}' https://explorer.incentivized-testnet.iohkdev.io/explorer/graphql`

    shelleyLastBlockCount=`echo $shelleyExplorerJson | grep -o '"endCursor":"[^"]*' | cut -d'"' -f4`
    deltaBlockCount=`echo $(($shelleyLastBlockCount-$lastBlockCount))`

    echo "----------"
    echo "LastBlockCount: " $lastBlockCount
    echo "LastShelleyBlockCount: " $shelleyLastBlockCount
    echo "DeltaBlockCount: " $deltaBlockCount
    echo "----------"

    # Once the delta is greater (node is behind explorer) than 3, or less than -3 (node is ahead of 
    # explorer), output a warning. If alerting from logs you can grep for "DeltaBlockCountWarning" 
    if [ $deltaBlockCount -gt 3 ]
    then
        echo "[DeltaBlockCountWarningBehind] Node is behind Explorer, delta: " $deltaBlockCount
        echo "----------"
    elif [ $deltaBlockCount -lt -3 ]
    then
        echo "[DeltaBlockCountWarningAhead] Node is ahead of Explorer, delta: " $deltaBlockCount
        echo "----------"
    fi
}