Send a Slack notification when load-balance status has been updated (for EdgeRouter)

lb-transition.sh

#!/bin/bash
RUN=/opt/vyatta/bin/vyatta-op-cmd-wrapper

# Slack Webhook
HOOK_URL=''

# Arguments
GROUP=$1
INTF=$2
STATUS=$3

# Message
WATCHDOG=$($RUN show load-balance watchdog)
TEXT="Status has been updated.\n\`\`\`$WATCHDOG\`\`\`"

# Parameters
PAYLOAD="{\"text\": \"$TEXT\"}"

# The last interface defined in the load-balance group
TARGET_INTF=$($RUN show configuration commands | grep "^set load-balance group $GROUP interface" | tail -1 | cut -d' ' -f6)

# Script is called multiple times by the alphabetical order of interfaces
# Send the notification only once
if [ "$INTF" = "$TARGET_INTF" ]; then
    curl -X POST --data-urlencode "payload=$PAYLOAD" $HOOK_URL
fi