Read-only app/etc/

[kassner]

Is there a reason for the app/etc/ path to be writable during php bin/magento setup:upgrade --keep-generated?

Looking into Magento\Framework\Setup\FilePermissions, the getMissingWritableDirectoriesForDbUpgrade asks for app/etc/ to be writable, but it's not clear what is being written to that folder.

My goal is to deploy magento in a read-only environment (except for the var/ folder), for an already installed Magento, so theoretically none of those files should be changed compared to what the CI builds.

Steps to reproduce

• Run chmod 555 app/etc
• Run chmod 444 app/etc/*
• Run ./bin/magento setup:upgrade --keep-generated

Actual Result

Additional Information

please do take also in consideration that it happens for env.php which in a cloud horizontal scaling environment with immutable artefacts deployed (Kubernetes, docker, aws lambda etc) is important to be able to manage it ourselves.

Command to output required changes would greatly help, as we could update the env.php for example in the secret Kubernetes injects and redeploy, the system having all state as it expects.

[m2-assistant]

Hi @kassner. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

• Summary of the issue
• Information on your environment
• Steps to reproduce
• Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento give me 2.4-develop instance - upcoming 2.4.x release

For more details, please, review the Magento Contributor Assistant documentation.

@kassner do you confirm that you were able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

---

• Join Magento Community Engineering Slack and ask your questions in #github channel.

[Zyles]

Magento needs write access to app/etc/config.php

[m2-assistant]

Hi @shikhamis11. Thank you for working on this issue.
In order to make sure that issue has enough information and ready for development, please read and check the following instruction: 👇

• 1. Verify that issue has all the required information. (Preconditions, Steps to reproduce, Expected result, Actual result).

  Details

  If the issue has a valid description, the label Issue: Format is valid will be added to the issue automatically. Please, edit issue description if needed, until label Issue: Format is valid appears.

• 2. Verify that issue has a meaningful description and provides enough information to reproduce the issue. If the report is valid, add Issue: Clear Description label to the issue by yourself.

• 3. Add Component: XXXXX label(s) to the ticket, indicating the components it may be related to.

• 4. Verify that the issue is reproducible on 2.4-develop branch

  Details

  - Add the comment @magento give me 2.4-develop instance to deploy test instance on Magento infrastructure.
  - If the issue is reproducible on 2.4-develop branch, please, add the label Reproduced on 2.4.x.
  - If the issue is not reproducible, add your comment that issue is not reproducible and close the issue and stop verification process here!

• 5. Add label Issue: Confirmed once verification is complete.

• 6. Make sure that automatic system confirms that report has been added to the backlog.

[shikhamis11]

hello @kassner
GitHub is only intended for magento 2 core issues .. for any discussion you can use Magneto Stack Exchange and Magento community Forum

[kassner]

@shikhamis11 it is a core issue, Magento does NOT run in a read-only filesystem. I'm asking those questions in an attempt to get a technical answer so I can send a pull request when applicable.

But if you guys don't want to answer this, please remove the "Developer experience issue" category when creating an issue on GitHub, because this is exactly this kind of issue.

[hostep]

@kassner: I kind of agree, if you provide the --keep-generated flag, I would expect that it won't write to the filesystem, therefore it wouldn't need to check if those files in app/etc/ are writeable.

So we first need to confirm that providing the --keep-generated flag is actually not attempting to write to those files (I have the feeling that it will still try). And if it is trying to write to those files, that would probably be considered a change request to make that no longer happen.
If it is not trying to write to those files with that flag provided, then the check for the writeable directories shouldn't happen.

Can somebody try to figure out if any writing to the filesystem is happening when providing the flag --keep-generated ? Thanks!

[Zyles]

M2 also needs write access to env.php for cache_types.

Which is dumb in itself. But that is how they chose to do it...

[hostep]

@Zyles: we are talking about the setup:upgrade command here. If @kassner choses to make those files read-only, then he won't be able to change cache statuses, but that's probably a good idea on a production environment.
(Only when a new cache type gets added to the shop, it might get a bit tricky, because from my experience, it's always disabled by default)

[shikhamis11]

thank you @hostep .. for making the issue more clear to me .
@Zyles issue is now opened .. It will be good If you update the issue description as per magento issue reporting guideline

Thanks

[kassner]

@hostep

I managed to successfully run Magento with a read-only filesystem and what I found is that setup:upgrade calls updateModulesSequence, which by itself calls createModulesConfig, which tries to update the modules array inside app/etc/config.php.

My patch just makes sure this call never happens when using --keep-generated, because when I'm deploying that code, the setup:upgrade was already executed somewhere else and config.php should have the list of modules defined and sorted.

@Zyles thanks for pointing out, it indeed writes it there:

www-data@magento-c0557941-7bcf4f766b-b9fjc:~/magento$ php bin/magento cache:disable config

In Writer.php line 148:
                                                        
  The "env.php" deployment config file isn't writable.  
                                                        

cache:disable [--bootstrap BOOTSTRAP] [--] [<types>...]

I guess it's OK to keep the env.php writable for that purpose (ideally we would have another file just for caching), because there is no other place to store that information. In any case, that doesn't justify having the config.php writable.