Check if a local nano node with RPC enabled is reachable. If not send an email.

check_nano_node.sh

# Before usage make sure to have a working mail setup. 
# If you are not sure what that means and you run Ubuntu just run "apt install mailutils" and 
# choose following settings (be sure to replace example.com with your domain):

#    General type of mail configuration?: Internet Site
#    System mail name: example.com
#    Root and postmaster mail recipient: username
#    Other destinations to accept mail for: $myhostname, example.com, mail.example.com, localhost.example.com, localhost
#    Force synchronous updates on mail queue?: No
#    Local networks: 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
#    Mailbox size limit: 0
#    Local address extension character: +
#    Internet protocols to use: all

# Add this to you cronjob by running "crontab -e" and 
# add the following line: "*/5 * * * * bash /path/to/your/check_nano_node.sh > /dev/null 2>&1" (without the quotes)
# Be sure that you replaced the path with your local path to the script.
# This will run the script every 5 minutes and discard any output if it is all fine.


# Check if the rpc is reachable with a simple action
if curl -k --data '{"action": "version"}' http://127.0.0.1:7076; then
    echo "success"
else
    # If not send the email. Be sure to insert your email here.
    echo "Alert: Nano node not reachable!" | mail -s "Nano Node RPC not reachable alert!" example@example.com
fi