block_watcher.sh

#!/bin/bash

remote_height=$(curl -s https://api.blockcypher.com/v1/eth/main | jq .height)
local_height=$(($(curl -sX POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}' http://127.0.0.1:8545 | jq -r .result)))

re='^[0-9]+$'
if ! [[ $remote_height =~ $re ]] ; then
   echo "error: remote_height is not a number" >&2; exit 1
fi

if ! [[ $local_height =~ $re ]] ; then
   echo "error: local_height not a number" >&2; exit 1
fi

echo "Blockcypher block height is " $remote_height
echo "Local block height is " $local_height
echo "Difference is " `expr $remote_height - $local_height`

if [[ `expr $remote_height - $local_height` -gt 10 ]]; then
	echo "Huston, we have a problem" && sudo systemctl restart openethereum \
	curl -s -X POST https://api.telegram.org/botXXX/sendMessage -d chat_id=-YYY -d text="Graph Ethereum Archive Node blocks are stopped to grow";
else
        echo "We are doing fine this time, lets check in a while";
fi