Upgrade Kernel from 5.0 to 5.1

[Cartman34]

Hello,

I got several hours of trouble upgrading Kernel because the upgrade & kernel usage is not documented.
Kernel class changed a lot between 5.0 & 5.1.

About my Kernel 5.0, this is a Kernel generated for new Symfony 5.0 project using composer create project command. I am using my own extension included in this Kernel to allow my own configuration file.
Kernel_5.0.php.txt

About my Kernel 5.1, this a Kernel generated for another brand new I imported and edited to include my own extension. My extension class was also moved to another namespace.
Kernel_5.1.php.txt

As you can see, bote files are really differents.

I advise all people upgrading the kernel to use the new one and to include their changes after.

[maxhelias]

The kernel is in a recipe, see the note to update your recipe : https://symfony.com/doc/current/setup/upgrade_minor.html#updating-recipes

[Cartman34]

Okay, so now, I understand more about recipes. But Is there any documentation about using Kernel ?

[maxhelias]

Like that ?
https://symfony.com/doc/current/reference/configuration/kernel.html or https://symfony.com/doc/current/configuration/front_controllers_and_kernel.html#the-kernel-class

[Cartman34]

Recipes does not contain information about upgrade, this is only replacing the existing files with new version.
These documentations about Kernel are incomplete, there is nothing about build container in Kernel.

[maxhelias]

About upgrading, the following command (compose recipes symfony/framework-bundle) as guide information for migration would be enough or not ?
The link "recipes history" displays the modifications made since the version installed on the project

If so, a little promotion in side of Flex about this command could correct this problem.

[javiereguiluz]

I'm closing this one in favor of:

• Update documentation for removal of config/bootstrap.php #13778 pull request which updates the docs to the latest recipe contents
• Improve discoverability of recipe changes flex#629 issue which is discussing ways to improve this situation for future updates.

Thanks!

[qharnay]

"If I may": updating recipes (and their related documentation) can only be relevant to bare symfony applications users.
What if an application makes uses of symfony ( ie : migrating a huge legacy app to tend to be a symfony app) and do not rely on recipes ?