Pipe your Monit email alerts into Slack

monit-alert-slack.sh

#!/bin/bash
# Save this file as e.g. /usr/local/bin/monit-alert-slack.sh
# then chmod +x /usr/local/bin/monit-alert-slack.sh
#
# In your /etc/monitrc set a user to get the alerts you
# want pushed to Slack:
#
# set alert monit-alerts@localhost
#
# and then in /etc/aliases set this as the user which
# this script is piped to:
#
# monit-alerts: |/usr/local/bin/monit-alert-slack.sh
#
# Then run newliases
#
# You'll need to ensure that e.g. exim has been configured to allow
# the pipe transport, otherwise the /etc/aliases config will be ignored
#
# SYSTEM_ALIASES_PIPE_TRANSPORT = address_pipe
#
#
# Dependencies: curl & formail
#
# Jay Caines-Gooby
# jay@gooby.org
# @jaygooby on Twitter

while read email
do
  case "$email" in
    Date:*)
      # the pipe to xargs removes leading and trailing whitespace
      MONIT_DATE=$(echo "${email}" | cut -d":" -f2- | xargs)
      ;;
    Subject:*)
      case "$email" in
        *succeeded* | *Exists*)
          SLACK_COLOUR=good
          ;;
        *matched* | *failed* | *Does*not*exist*)
          SLACK_COLOUR=danger
          ;;
        *)
        SLACK_COLOUR=warning
        ;;
      esac
      MONIT_SUBJECT=$(echo "${email}" | cut -d":" -f2- | xargs)
      ;;
    *) 
      if [ -z "$MONIT_BODY" ]; then
        MONIT_BODY="$email"
      else
        MONIT_BODY="${MONIT_BODY}\n${email}"
      fi
      ;;
  esac
done < <(formail -k -X Subject: -X Date:)

echo SLACK_COLOUR is $SLACK_COLOUR
/usr/bin/curl \
    -X POST \
    -s \
    --data-urlencode "payload={ \
        \"channel\": \"#server-chatter\", \
        \"username\": \"Monit\", \
        \"pretext\": \"$MONIT_DATE | $MONIT_SUBJECT\", \
        \"color\": \"$SLACK_COLOUR\", \
        \"icon_emoji\": \":eyes:\", \
        \"text\": \"$MONIT_BODY\" \
    }" \
    https://hooks.slack.com/services/<incoming>/<webhook url>/<your Slack API key>