MX Phinx Migrations
About
The MX_PhinxMigrations module integrates Phinx database migrations into Magento 2 as a replacement for the built-in setup:upgrade
method of triggering schema and data changes, therefore enabling zero-downtime deployments.
Why?
The idea of this module is to avoid having to change module versions (in module.xml
files) in order to trigger database changes in Magento. When Magento bootstraps itself it verifies that all module versions in the setup_module
database table match the versions on disk. If a module version in the database does not match the version in our code then Magento will error and show something like:
1 exception(s):
Exception #0 (Magento\Framework\Exception\LocalizedException): Please upgrade your database: Run "bin/magento setup:upgrade" from the Magento root directory.
The following modules are outdated:
Acme_Foo schema: current version - 0.2.0, required version - 0.3.0
Acme_Foo data: current version - 0.2.0, required version - 0.3.0
If we consider the following high level deployment process, this makes zero-downtime deployments impossible due to the fact that at some point, even if just for a very short time, the code and database versions will be out of sync between steps 2 and 3:
- Build Magento container
- Before deploying the new container(s), run
setup:upgrade
process on the target environment database - Deploy the new container(s)
Requirements
The module is currently supported on Magento >= 2.1.
Installing
Add the module to the require section of the composer file:
$ composer require mx/module-phinx-migrations
Enabling the module
$ bin/magento setup:upgrade
$ bin/magento c:c
We can verify that the module is enabled by running the status command:
$ bin/magento module:status MX_PhinxMigrations
The phinx configuration file
After installing the module you will need to create a phinx.php
file in your project root folder.
An example can be found here. There should be no further changes required to this file but it can be edited as necessary for your project setup.
Using
Migrations are custom classes that extend phinx
migrations and execute some code to change the DB. Migration class files can sit in any of your Magento modules (phinx
will scan for all migration folders at run time) in the following locations:
src/*/*/etc/migrations
app/code/*/*/etc/migrations
Creating a migration
phinx
can create a migration for us. For example
bin/phinx create AddProductPimIdAttribute
It will then ask us which module we want to add the migration file to:
Which migrations path would you like to use?
[0] src/Foo/Catalog/etc/migrations
[1] src/Foo/Sales/etc/migrations
>
When the migration file is created in the selected destination we should see a class similar to the following:
When writing our migration we should always include rollback code so that we can reverse deployments easily.
Magento setup helpersWe have access to 3 different setup helpers provided by Magento in each migration:
$this->schemaSetup
(instance of Magento\Framework\Setup\SchemaSetupInterface
)
$this->dataSetup
(instance of Magento\Framework\Setup\ModuleDataSetupInterface
)
$this->eavSetup
(instance of Magento\Eav\Setup\EavSetup
)
Execute migrationsWhen you are happy with your migration you can execute it as follows
bin/phinx migrate
Rolling backIf you want to undo your migration then simply execute
bin/phinx rollback
Limitations
- Upgrading Magento itself will still result in version changes in the Magento
module.xml
files, therefore zero-downtime deployments are not possible in this situation.
FAQ / troubleshootingQ. When I run bin/phinx create ...
it cannot find any migration paths to create the migration file, why?
A. In order for a migration to be created phinx
will scan your project for migration
folders in the paths mentioned in the section above. Make sure you create at least one migration
folder inside one of your Magento module's etc
folders and then it should work as expected.