@dlandon Your OwnCloud docker ran fine for about a year. Other than auto-updates I had no reason to ever change something, but a few days ago my calendars stopped to synchronize. Checking the web interface for reasons I found this instead:
Exception occurred while logging exception: Failed to connect to the database: An exception occured in driver: SQLSTATE[HY000] [2002] No such file or directory
#0 /config/www/owncloud/lib/composer/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(429): OC\DB\Connection->connect()
#1 /config/www/owncloud/lib/composer/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(389): Doctrine\DBAL\Connection->getDatabasePlatformVersion()
#2 /config/www/owncloud/lib/composer/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(328): Doctrine\DBAL\Connection->detectDatabasePlatform()
#3 /config/www/owncloud/lib/composer/doctrine/dbal/lib/Doctrine/DBAL/Connection.php(623): Doctrine\DBAL\Connection->getDatabasePlatform()
#4 /config/www/owncloud/lib/private/DB/Connection.php(145): Doctrine\DBAL\Connection->setTransactionIsolation(2)
#5 /config/www/owncloud/lib/composer/doctrine/dbal/lib/Doctrine/DBAL/DriverManager.php(172): OC\DB\Connection->__construct(Array, Object(Doctrine\DBAL\Driver\PDOMySql\Driver), Object(Doctrine\DBAL\Configuration), Object(Doctrine\Common\EventManager))
#6 /config/www/owncloud/lib/private/DB/ConnectionFactory.php(145): Doctrine\DBAL\DriverManager::getConnection(Array, Object(Doctrine\DBAL\Configuration), Object(Doctrine\Common\EventManager))
#7 /config/www/owncloud/lib/private/Server.php(493): OC\DB\ConnectionFactory->getConnection('mysql', Array)
#8 /config/www/owncloud/lib/composer/pimple/pimple/src/Pimple/Container.php(113): OC\Server->OC\{closure}(Object(OC\Server))
#9 /config/www/owncloud/lib/private/AppFramework/Utility/SimpleContainer.php(111): Pimple\Container->offsetGet('DatabaseConnect...')
#10 /config/www/owncloud/lib/private/ServerContainer.php(87): OC\AppFramework\Utility\SimpleContainer->query('DatabaseConnect...')
#11 /config/www/owncloud/lib/private/Server.php(1160): OC\ServerContainer->query('DatabaseConnect...')
#12 /config/www/owncloud/lib/private/Server.php(370): OC\Server->getDatabaseConnection()
#13 /config/www/owncloud/lib/composer/pimple/pimple/src/Pimple/Container.php(113): OC\Server->OC\{closure}(Object(OC\Server))
#14 /config/www/owncloud/lib/private/AppFramework/Utility/SimpleContainer.php(111): Pimple\Container->offsetGet('AppConfig')
#15 /config/www/owncloud/lib/private/ServerContainer.php(87): OC\AppFramework\Utility\SimpleContainer->query('AppConfig')
#16 /config/www/owncloud/lib/private/Server.php(1089): OC\ServerContainer->query('AppConfig')
#17 /config/www/owncloud/lib/private/Server.php(547): OC\Server->getAppConfig()
#18 /config/www/owncloud/lib/composer/pimple/pimple/src/Pimple/Container.php(113): OC\Server->OC\{closure}(Object(OC\Server))
#19 /config/www/owncloud/lib/private/AppFramework/Utility/SimpleContainer.php(111): Pimple\Container->offsetGet('AppManager')
#20 /config/www/owncloud/lib/private/ServerContainer.php(87): OC\AppFramework\Utility\SimpleContainer->query('AppManager')
#21 /config/www/owncloud/lib/private/Server.php(1359): OC\ServerContainer->query('AppManager')
#22 /config/www/owncloud/lib/private/legacy/app.php(346): OC\Server->getAppManager()
#23 /config/www/owncloud/lib/private/legacy/app.php(110): OC_App::getEnabledApps()
#24 /config/www/owncloud/lib/base.php(579): OC_App::loadApps(Array)
#25 /config/www/owncloud/lib/base.php(998): OC::init()
#26 /config/www/owncloud/index.php(54): require_once('/config/www/own...')
#27 {main}
Looks like something very much internal to the docker. I tried (after backing up appdata) a forced update, to remove the container and cleanly reinstall it, changing the additional options, the network interface (since intermediately I had no access to the web GUI at all) - all without success.
Any pointers, please?!