Unable to enable maintenance mode when env.php is read only

[ihor-sviziev]

Preconditions (*)

1. Magento 2.3.2 & 2.3-develop
2. Make env.php file read only: chmod -w app/etc/env.php or chmod 754 app/etc/env.php

Steps to reproduce (*)

1. Run php bin/magento maintenance:enable -v

Expected result (*)

1. Maintenance mode should be enabled

Actual result (*)

1. Maintenance mode is not enabled
2. Command fails with following output
   

In PathValidator.php line 63:
                                                                                                          
  [Magento\Framework\Exception\ValidatorException]                                                        
  Path "/var/www/html/magento2/app/etc/" cannot be used with directory "/var/www/html/magento2/app/etc/"  
                                                                                                          

Exception trace:
 () at /var/www/html/magento2/vendor/magento/framework/Filesystem/Directory/PathValidator.php:63
 Magento\Framework\Filesystem\Directory\PathValidator->validate() at /var/www/html/magento2/vendor/magento/framework/Filesystem/Directory/Read.php:82
 Magento\Framework\Filesystem\Directory\Read->validatePath() at /var/www/html/magento2/vendor/magento/framework/Filesystem/Directory/Read.php:111
 Magento\Framework\Filesystem\Directory\Read->getAbsolutePath() at /var/www/html/magento2/vendor/magento/framework/Filesystem/Directory/Write.php:57
 Magento\Framework\Filesystem\Directory\Write->assertWritable() at /var/www/html/magento2/vendor/magento/framework/Filesystem/Directory/Write.php:326
 Magento\Framework\Filesystem\Directory\Write->openFile() at /var/www/html/magento2/vendor/magento/framework/Filesystem/Directory/Write.php:343
 Magento\Framework\Filesystem\Directory\Write->writeFile() at /var/www/html/magento2/vendor/magento/framework/App/DeploymentConfig/Writer.php:146
 Magento\Framework\App\DeploymentConfig\Writer->saveConfig() at /var/www/html/magento2/vendor/magento/framework/App/Cache/State.php:104
 Magento\Framework\App\Cache\State->persist() at /var/www/html/magento2/vendor/magento/framework/App/Cache/Manager.php:77
 Magento\Framework\App\Cache\Manager->setEnabled() at /var/www/html/magento2/vendor/magento/module-page-cache/Observer/SwitchPageCacheOnMaintenance.php:73
 Magento\PageCache\Observer\SwitchPageCacheOnMaintenance->turnOffFullPageCache() at /var/www/html/magento2/vendor/magento/module-page-cache/Observer/SwitchPageCacheOnMaintenance.php:55
 Magento\PageCache\Observer\SwitchPageCacheOnMaintenance->execute() at /var/www/html/magento2/vendor/magento/framework/Event/Invoker/InvokerDefault.php:88
 Magento\Framework\Event\Invoker\InvokerDefault->_callObserverMethod() at /var/www/html/magento2/vendor/magento/framework/Event/Invoker/InvokerDefault.php:74
 Magento\Framework\Event\Invoker\InvokerDefault->dispatch() at /var/www/html/magento2/vendor/magento/framework/Event/Manager.php:66
 Magento\Framework\Event\Manager->dispatch() at /var/www/html/magento2/vendor/magento/framework/App/MaintenanceMode.php:82
 Magento\Framework\App\MaintenanceMode->set() at /var/www/html/magento2/setup/src/Magento/Setup/Console/Command/AbstractMaintenanceCommand.php:90
 Magento\Setup\Console\Command\AbstractMaintenanceCommand->execute() at /var/www/html/magento2/vendor/symfony/console/Command/Command.php:255
 Symfony\Component\Console\Command\Command->run() at /var/www/html/magento2/vendor/symfony/console/Application.php:893
 Symfony\Component\Console\Application->doRunCommand() at /var/www/html/magento2/vendor/symfony/console/Application.php:262
 Symfony\Component\Console\Application->doRun() at /var/www/html/magento2/vendor/magento/framework/Console/Cli.php:105
 Magento\Framework\Console\Cli->doRun() at /var/www/html/magento2/vendor/symfony/console/Application.php:145
 Symfony\Component\Console\Application->run() at /var/www/html/magento2/bin/magento:23

maintenance:enable [--ip IP] [--magento-init-params MAGENTO-INIT-PARAMS]

3. Exception message isn't saying anything, message not valid at all.

Additional info

Why it's important to keep env.php file read only - on production servers it's the only one way to make sure that no one will disable cache --> website will work fine.

My investigation shown that this issue appeared in 0e37353.
If i'll remove following observer - it works fine:

magento2/app/code/Magento/PageCache/etc/events.xml

Lines 60 to 62 in 0e37353

	<event name="maintenance_mode_changed">
	<observer name="page_cache_switcher_for_maintenance" instance="Magento\PageCache\Observer\SwitchPageCacheOnMaintenance"/>
	</event>

I reviewed this commit and actually it's ok that FPC should not cache pages in maintenance mode, but disabling FPC at all- the wrong way.

What I would suggest - revert changes that were done in 0e37353 and add checking for maintenance flag in when we're sending public Cache-Control headers

[m2-assistant]

Hi @ihor-sviziev. 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 2.3-develop instance - upcoming 2.3.x release

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

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

• yes
• no

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[magento-engcom-team]

✅ Confirmed by @engcom-Charlie
Thank you for verifying the issue. Based on the provided information internal tickets MC-19601 were created

Issue Available: @engcom-Charlie, You will be automatically unassigned. Contributors/Maintainers can claim this issue to continue. To reclaim and continue work, reassign the ticket to yourself.

[irving0mar]

#cd19latam

[m2-assistant]

Hi @irving0mar. Thank you for working on this issue.
Looks like this issue is already verified and confirmed. But if you want to validate it one more time, please, go though the following instruction:

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

• 2. Verify that the issue is reproducible on 2.3-develop branch

  Details

  - Add the comment @magento give me 2.3-develop instance to deploy test instance on Magento infrastructure.
  - If the issue is reproducible on 2.3-develop branch, please, add the label Reproduced on 2.3.x.
  - If the issue is not reproducible, add your comment that issue is not reproducible and close the issue and stop verification process here!

• 3. If the issue is not relevant or is not reproducible any more, feel free to close it.

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[irving0mar]

We can't reproduce this issue on Centos 7 and Magento 2.3-develop, give us more information please. For example, what is the OS you are using.

[ihor-sviziev]

We can't reproduce this issue on Centos 7 and Magento 2.3-develop, give us more information please. For example, what is the OS you are using.

I had this issue on Ubuntu 18.04 and on Amazon Linux (Cent OS based). I don’t think it’s related.
I think main issue - you have to run bin/magento not from root user, because even without permissions root user could write to all files