Simple server health check, that sends failure to a discord or slack channel

status-check

#!/bin/sh

## simple server health checker. when the service does not respond it calls a 
## Discord or Slack webhook

## adjust values below according to you needs:
server=www.google.com
service=discord
webhook_url="https://discordapp.com/api/webhooks/...."

ping -c 4 $server

if [[ $? != 0 ]]; then
  failure="Possibly down: The server '${server}' did not respond to a ping"
fi

# if [[ -z $failure ]]; then
#   port_number=80
#   nc -zvw10 "$server" "${port_number}" > /dev/null
#   
#   if [[ $? != 0 ]]; then
#     failure="Possibly down: Port ${port_number} on ${server} is closed"
#   fi
# fi


if [[ -z $failure ]]; then
  status_code=$(curl -s -o /dev/null -w "%{http_code}" "https://${server}")
    
  if [[ $? != 0 ]]; then
    failure="Possibly down: Webserver on ${server} did not respond"
  elif [[ $status_code != "200" ]]; then 
    failure="Possibly down: Test page on ${server} responded with ${status_code}" 
  fi
fi

if [[ -n $failure ]]; then
  echo "error: ${failure}"
  
  if [[ $service == "discord" ]]; then  
json=$(cat <<EOF
  {
     "username": "Server Health Checker",
     "content": "$failure"
  }
EOF
)
  elif [[ $service == "slack" ]]; then
json=$(cat <<EOF
  {
     "text": "$failure"
  }
EOF
)  
  fi


  curl -X POST -H "Content-Type: application/json" -d "$json" "$webhook_url"
fi