'Permission denied' connecting from instance to database

Question

I cannot connect from my Lightsail instances to the Lightsail database, always 'permission denied'.  
I can connect to the same database remotely with public mode enabled.  
  
In my app I have the connection string defined as:

```
'db' =>
		[
			'dsn'         => 'mysql:dbname=dbmaster;host=endpoint;port=3306',
			'username'    => 'username',
			'password'    => 'password',
			'persistent'  => false,
			'log_queries' => false,
			'reconnect'   => false,
			'queries'     =>
			[
				'SET NAMES UTF8',
			],
		],
```

Edited by: Lester on Apr 7, 2020 6:05 PM  
Preview looks fine, published version not same, special characters converted to html entity codes.

Lester · Answer

If anyone else encounters this, this was the reason:  
  
"..By default, the httpd_can_network_connect_db Boolean is off, preventing Apache HTTP Server scripts and modules from connecting to database servers.."  
  
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/selinux_users_and_administrators_guide/sect-security-enhanced_linux-working_with_selinux-booleans  
  
setsebool -P httpd_can_network_connect_db on

'Permission denied' connecting from instance to database

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