Upgrading from Magento <=2.2.x to 2.3.x

At some point you’re going to want to upgrade your Magento project from 2.0/2.1/2.2 to the latest 2.3.x release to take advantage of new functionality and many improvements. There are a few manual changes that get in the way of the standard composer update that you’re used to. Thankfully, to accommodate this obstacle a tool was included in the codebase to automate these changes for you.

Prep:


# Create a fresh Magento 2.3 project via composer (or clone the repo and switch to a 2.3 tag/branch, or grab the script by itself..)
composer create-project --repository=https://repo.magento.com/ magento/project-community-edition=2.3 m23base


# Change working directories to the upgrade tools directory in your new project
cd m23base/dev/tools/UpgradeScripts

Execute:

# Run the 2.3 upgrade assistant against the root of the Magento project you’re intending to upgrade
php -f pre_composer_update.php — –root=/path/to/magento-installation –repo=https://repo.magento.com/

Output:
– Updated composer.json
– Updated update/composer.lock
– Updated update/dev/tests

Change working directories to the root of the Magento project you’ve begun updating and complete the remaining steps.


cd /path/to/magento-installation


# Update Magento and all dependencies
composer update

# Clear the cache
rm -rf /var/cache/*
rm -rf /var/page_cache/*

# Remove any generated code
rm -rf /var/generation
rm -rf /generated/code/*

# Run Magento upgrade scripts
php bin/magento setup:upgrade

# Reindex after upgrade
php bin/magento i:rei

# Flush cache after reindex
php bin/magento c:f

Reading:

Documentation:
– https://devdocs.magento.com/guides/v2.3/comp-mgr/cli/cli-upgrade.html#upgrade-cli-script