Nagios to post alerts into a Slack channel # using the Incoming WebHooks integration

nagios-slack-alert.sh

#!/bin/bash

# This script is used by Nagios to post alerts into a Slack channel
# using the Incoming WebHooks integration. Create the channel, botname
# and integration first and then add this notification script in your
# Nagios configuration.
#
# All variables that start with NAGIOS_ are provided by Nagios as
# environment variables when an notification is generated.
# A list of the env variables is available here:
#   http://nagios.sourceforge.net/docs/3_0/macrolist.html
#
# My info
# Website: bytesunlimited.com
# GitHub: https://github.com/BytesUnlimited
#
#### Config Examples:
#
## Commands Definition:
# # 'notify-host-by-slack' command definition
# define command{
#         command_name    notify-host-by-slack
#         command_line    /usr/lib64/nagios/plugins/nagios-slack-alert.sh "$HOSTNAME$" "N/A" "$HOSTSTATE$" "$HOSTOUTPUT$" "$NOTIFICATIONTYPE$"
#         }
#
# # 'notify-service-by-slack' command definition
# define command{
#         command_name    notify-service-by-slack
#         command_line    /usr/lib64/nagios/plugins/nagios-slack-alert.sh "$HOSTNAME$" "$SERVICEDESC$" "$SERVICESTATE$" "$SERVICEOUTPUT$" "$NOTIFICATIONTYPE$"
#
## Contacts Example:
# define contact {
#         contact_name                    slack-default
#         alias                           Slack Default
#         service_notification_period     24x7
#         host_notification_period        24x7
#         service_notification_options    w,u,c,r
#         host_notification_options       d,r
#         service_notification_commands   notify-service-by-slack
#         host_notification_commands      notify-host-by-slack
#         }
#
## Contact Group Example:
# define contactgroup{
#         contactgroup_name       slacknotificationsgroup
#         alias                   Slack Default Notifications
#         members                 slack-default
#         }
#
## Service Example:
# define service{
#         use                             default-service
#         service_description             Check Example Command Description
#         check_command                   check_example_command
#         contact_groups                  slacknotificationsgroup
#         host_name                       server-name
#         }
#

#Modify these variables for your environment
MY_NAGIOS_HOSTNAME="MY-IP-OR-Domain-Name"
MY_NAGIOS_STATUS_URL="https://${MY_NAGIOS_HOSTNAME}/nagios/cgi-bin/status.cgi?host=${NAGIOS_HOSTNAME}"
SLACK_HOSTNAME="SLACK-EXTENSION.slack.com"
SLACK_CHANNEL="#CHANNEL-NAME"
SLACK_BOTNAME="Nagios Alerts"
WEBHOOKS_INTEGRATION_URL="https://hooks.slack.com/services/CHANGE-ME/CHANGE-ME/CHANGE-ME"
NAGIOS_SERVICESTATE="@3"

#Set the message icon based on Nagios service state
if [ "$NAGIOS_SERVICESTATE" = "CRITICAL" ]
then
    ICON=":banging-head:"
    COLOR="danger"
elif [ "$NAGIOS_SERVICESTATE" = "WARNING" ]
then
    ICON=":face_with_head_bandage:"
    COLOR="warning"
elif [ "$NAGIOS_SERVICESTATE" = "OK" ]
then
    ICON=":excellent:"
    COLOR="good"
elif [ "$NAGIOS_SERVICESTATE" = "UNKNOWN" ]
then
    ICON=":question:"
    COLOR="#00FFFF"
else
    ICON=":facepalm:"
    COLOR="#FFFFFF"
fi

#Send message to Slack using Incoming WebHooks Integration:
curl -X POST --data "payload={\"channel\": \"${SLACK_CHANNEL}\", \"username\": \"${SLACK_BOTNAME}\", \"icon_url\": \"https://slack.com/img/services/nagios_48.png\", \"text\": \"${ICON} HOST: ${1}   SERVICE: ${2}     MESSAGE: ${4} <${MY_NAGIOS_STATUS_URL}|See Nagios>\"}" $WEBHOOKS_INTEGRATION_URL