Check if newer version of a Chrome extension is available in the Webstore and send notification to Slack

versioncheck.sh

#!/bin/bash

# Use this script from cron to check if newer version of a Chrome extension is available and send notification to Slack
# Requirements: curl, jq, unzip
# Author: rlanyi

if [ "$#" -ne 3 ]; then
    echo "Usage: ./versioncheck.sh <extension_id> <version> <slack_webhook_url>"
    echo
    echo "<extension_id>	Chrome Webstore extension id (32 chars)"
    echo "<version>		version to compare to"
    echo "<slack_webhook_url>	Slack notification target URL on version change"
    exit
fi

extension_id="$1"
base_version="$2"
webhook_url="$3"

rm /tmp/${extension_id}.zip 2> /dev/null
curl -s -L -o /tmp/${extension_id}.zip "https://clients2.google.com/service/update2/crx?response=redirect&os=linux&arch=x86-64&os_arch=x86-64&nacl_arch=x86-64&prod=chromiumcrx&prodchannel=unknown&prodversion=67.0.3396.79&acceptformat=crx2,crx3&x=id%3D${extension_id}%26uc"
version=$(unzip -q -c /tmp/${extension_id}.zip manifest.json 2> /dev/null | jq -r .version)

if [ $version != $base_version ]; then
    curl -s -X POST --data-urlencode "payload={\"username\": \"Chrome Extension Checker\", \"text\": \"Extension <https://chrome.google.com/webstore/detail/xxx/${extension_id}|${extension_id}> in Google Chrome Webstore has been upgraded to v${version}\", \"icon_emoji\": \":arrow_double_up:\"}" ${webhook_url} > /dev/null
fi