Database connection error, after CLI install?

Question

First time Magento user here, seeking enlightenment. I did a CLI install on CentOS 7 using the following command...

./bin/magento setup:install 
 --base-url="http://example.com/shop/"
 --db-host="127.0.0.1" --db-name="th_magento"
 --db-user="th_magento" --db-password="asdfashd238"
 --admin-firstname="Hugh" --admin-lastname="Mongous"
 --admin-email="[email protected]" --admin-user="admin"
 --admin-password="b39fe8a09" --backend-frontname="aaa"

[... ssh buffer too small ...]

Module 'Magento_WebapiAsync':
[Progress: 818 / 833]
Module 'Magento_WebapiSecurity':
[Progress: 819 / 833]
Module 'Magento_Weee':
[Progress: 820 / 833]
Module 'Magento_WeeeGraphQl':
[Progress: 821 / 833]
Module 'Magento_CatalogWidget':
[Progress: 822 / 833]
Module 'Dotdigitalgroup_Email':
[Progress: 823 / 833]
Module 'Magento_WishlistAnalytics':
[Progress: 824 / 833]
Module 'Magento_WishlistGraphQl':
[Progress: 825 / 833]
Module 'Temando_Shipping':
[Progress: 826 / 833]
Module 'Vertex_Tax':
[Progress: 827 / 833]
[Progress: 828 / 833]
Installing admin user...
[Progress: 829 / 833]
Caches clearing:
Cache cleared successfully
[Progress: 830 / 833]
Disabling Maintenance Mode:
[Progress: 831 / 833]
Post installation file permissions check...
For security, remove write permissions from these directories: '/home/example/public_html/shop/app/etc'
[Progress: 832 / 833]
Write installation date...
[Progress: 833 / 833]
[SUCCESS]: Magento installation complete.
[SUCCESS]: Magento Admin URI: /aaa
Nothing to import.

For some reason I can't understand¹ all I get when I navigate to /aaa is an Error while establishing database connection message (rough translation, locale is not english).

I tried some basic troubleshooting like checking requirements with the web based install, and ensuring that I can login using the MySQL client and it works. I can't find the logs for the error, tough...

I can post additional data if needed. It might be worth noting the SQL server is MariaDB 10.0 and that the frontend shows no errors (it seems to display correctly).

---

1: Wouldn't the install stop before the [SUCCESS]: Magento installation complete. if there was a problem?

---

Update: env.php

The db user and password match...

'db' => [
        'table_prefix' => '',
        'connection' => [
            'default' => [
                'host' => 'localhost',
                'dbname' => 'th_magento',
                'username' => 'th_magento',
                'password' => 'asdfashd238',
                'model' => 'mysql4',
                'engine' => 'innodb',
                'initStatements' => 'SET NAMES utf8;',
                'active' => '1'
            ]
        ]
    ],

While at it I also enabled developer mode, but nothing changed in the error page html. The var/log/debug.log file contains only cache_invalidate entries, while connector.log is empty.

Answer 1

Please try:

php bin/magento setup:install 
     --base-url="http://example.com/shop/"
     --db-host="127.0.0.1" 
     --db-name="th_magento"
     --db-user="th_magento" 
     --db-password="asdfashd238"
     --admin-firstname="Hugh" 
     --admin-lastname="Mongous"
     --admin-email="[email protected]" 
     --admin-user="admin"
     --admin-password="b39fe8a09" 
     --backend-frontname="aaa"
     --language="en_US"
     --currency="USD"
     --timezone="America/Chicago"
     --use-rewrites=1

Answer 2

Try switching from localhost to 127.0.0.1 or vice versa for your database host in the magento configuration. Failing that you might have to put the FQDN to the database server.