How to update Magento 2.1.7 to Magento 2.2 ? Is it possible to upgrade?

Below is how I upgraded from 2.1.9 to 2.2.0 :

bin/magento maintenance:enable
composer require magento/product-community-edition 2.2.0 --no-update
composer update
rm -rf var/cache/*
rm -rf var/page_cache/*
rm -rf var/generation/*
chmod +x bin/magento
bin/magento setup:upgrade
bin/magento maintenance:disable

For further upgrades, change the version number:

composer require magento/product-community-edition 2.2.4 --no-update

I had problems with some custom modules. Check for updates from Magento 2.2 for custom modules used on:

Magento\Framework\Mail\TransportInterface - add new method getMessage

(Modules Smtp, Mail etc)

Magento\Rule\Model\AbstractModel - serialization replaced by json

(Modules used Rule)