Nextcloud unable to connect to MySQL container

[ordinaly]

Hello, I have recently modified the port mapping for my Nextcloud container, so I restarted the NC container and since then it is unable to connect to the MySQL DB.

OS: Debian GNU/Linux 8 (jessie)

NC container logs:

PHP Fatal error: Uncaught Doctrine\DBAL\DBALException: Failed to connect to the database: An exception occured in driver: SQLSTATE[HY000] [2002] php_network_getaddresses: getaddrinfo failed: Try again in /config/www/nextcloud/lib/private/DB/Connection.php:64
Stack trace:
#0 /config/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(429): OC\DB\Connection->connect()
#1 /config/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(389): Doctrine\DBAL\Connection->getDatabasePlatformVersion()
#2 /config/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(328): Doctrine\DBAL\Connection->detectDatabasePlatform()
#3 /config/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(623): Doctrine\DBAL\Connection->getDatabasePlatform()
#4 /config/www/nextcloud/lib/private/DB/Connection.php(151): Doctrine\DBAL\Connection->setTransactionIsolation(2)
#5 /config/www/nextcloud/3rdparty/doctrine/dbal/lib/Doctrine/DBAL/DriverManager.php(172): OC\DB\Connection->__construct(Array in /config/www/nextcloud/lib/private/DB/Connection.php on line 64

My config file:

<?php
$CONFIG = array (
  'memcache.local' => '\\OC\\Memcache\\APCu',
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'redis' => 
  array (
    'host' => 'redis',
    'port' => 6379,
  ),
  'datadirectory' => '/data',
  'instanceid' => 'ocq371i1672w',
  'passwordsalt' => '',
  'secret' => '',
  'trusted_domains' => 
  array (
    0 => '192.168.0.66'
  ),
  'overwrite.cli.url' => 'https://192.168.0.66',
  'dbtype' => 'mysql',
  'version' => '15.0.2.0',
  'dbname' => 'nextcloud',
  'dbhost' => 'mysql',
  'dbport' => '3306',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'oc_admin2',
  'dbpassword' => '',
  'installed' => true,
  'maintenance' => false,
  'theme' => '',
  'loglevel' => 2,
  'mail_from_address' => '',
  'mail_smtpmode' => 'smtp',
  'mail_domain' => 'gmail.com',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_smtpauth' => 1,
  'mail_smtphost' => 'smtp.gmail.com',
  'mail_smtpport' => '465',
  'mail_smtpname' => '',
  'mail_smtppassword' => '',
  'mail_smtpsecure' => 'ssl',
);

I linked the NC container to the DB container using --link mysqldb:mysql where mysqldb is the name of the mysql container. I have checked that the DB container is up and running and I am able to ping it from the NC container.

Any help is appreciated

[j0nnymoe]

Link is being deprecated in docker, it's best to use docker networking to link containers these days.

[ordinaly]

I tried to set up a macvlan network but I didn't figure out how to access the container from the browser once it is attached to the network ?
I also tried to fire up a docker-compose but ran into the same issue

[homerr]

Not sure about macvlan in docker, as this should be internal networking on the docker host unless you're attempting to use a remote SQL instance?

Some more information would be appreciated here, your docker run/compose.yml files and how you are trying to do this. We might be able to figure this one out for you then.

[thelamer]

@gaussianblurs for stuff like this it is much easier to help you out on Discord. As this is not a bug specific to this container or a change we can make in the codebase as we have multiple users connecting Nextcloud up to MySQL please hop in here and we can help you out:

https://discord.gg/YWrKVTn