#!/bin/bash

# Set Slack WebHook Channel URL 
SLACK_WEBHOOK_URL="<custom variable>"

Usage() {
cat << EOF
host-by-slack notification script for Icinga 2
The following are mandatory:
  -4 HOSTADDRESS (\$address$)
  -d LONGDATETIME (\$icinga.long_date_time$)
  -l HOSTALIAS (\$host.name$)
  -n HOSTDISPLAYNAME (\$host.display_name$)
  -o HOSTOUTPUT (\$host.output$)
  -s HOSTSTATE (\$host.state$)
  -t NOTIFICATIONTYPE (\$notification.type$)
And these are optional:
  -b NOTIFICATIONAUTHORNAME (\$notification.author$)
  -c NOTIFICATIONCOMMENT (\$notification.comment$)
  -v (\$notification_logtosyslog$, Default: false)
  -D DEBUG enable debug output - meant for CLI debug only
EOF

exit 1;
}

while getopts 4::b:c:d:hi:l:n:o:s:t:u:v:D opt
do
  case "$opt" in
    4) HOSTADDRESS=$OPTARG ;;
    b) NOTIFICATIONAUTHORNAME=$OPTARG ;;
    c) NOTIFICATIONCOMMENT=$OPTARG ;;
    d) LONGDATETIME=$OPTARG ;;
    h) Usage ;;
    l) HOSTALIAS=$OPTARG ;;
    n) HOSTDISPLAYNAME=$OPTARG ;;
    o) HOSTOUTPUT=$OPTARG ;;
    s) HOSTSTATE=$OPTARG ;;
    t) NOTIFICATIONTYPE=$OPTARG ;;
    v) VERBOSE=$OPTARG ;;
    D) DEBUG=1; echo -e "\n**********************************************\nWARNING: DEBUG MODE, DEACTIVATE ASAP\n**********************************************\n" ;;
   \?) echo "ERROR: Invalid option -$OPTARG" >&2
       Usage ;;
    :) echo "Missing option argument for -$OPTARG" >&2
       Usage ;;
    *) echo "Unimplemented option: -$OPTARG" >&2
       Usage ;;
  esac
done

# Set the message icon based on ICINGA Host state
if [ "$HOSTSTATE" = "DOWN" ]
then
    COLOR="#FF0000"
elif [ "$HOSTSTATE" = "UP" ]
then
    COLOR="#008000"
else
    COLOR=""
fi

# Send message to Slack
read -d '' PAYLOAD << EOF
{
  "attachments": [
    {
      "fallback": "${HOSTSTATE}: ${HOSTDISPLAYNAME}",
      "color": "${COLOR}",
      "fields": [
	{
	  "title": "Date:",
          "value": "${LONGDATETIME}",
          "short": true
	},
	{
	  "title": "Type:",
          "value": "${NOTIFICATIONTYPE}",
          "short": true
        },
        {
          "title": "Host:",
          "value": "${HOSTALIAS} (${HOSTADDRESS})",
          "short": true
        },
        {
          "title": "State:", 
          "value": "${HOSTSTATE}",
          "short": true
        },
	{
          "title": "Info:",
          "value": "${HOSTOUTPUT}",
          "short": true
        },
        {
          "title": "Author:",
          "value": "${NOTIFICATIONAUTHORNAME}",
          "short": true
        },
        {
          "title": "Comment:",
          "value": "${NOTIFICATIONCOMMENT}",
          "short": true
        }
      ]
    }
  ]
}
EOF

curl --connect-timeout 30 --max-time 60 -s -S -X POST -H 'Content-type: application/json' --data "${PAYLOAD}" "${SLACK_WEBHOOK_URL}"