Wordpress: Docker Image Fails To Work With Latest MySQL8 Docker Image

[jonmchan]

Tried using wordpress with mysql:latest docker image. I get the following error trying to connect to the DB:

Warning: mysqli_real_connect(): Unexpected server respose while doing caching_sha2 auth: 109 in /var/www/html/wp-includes/wp-db.php on line 1531

Warning: mysqli_real_connect(): MySQL server has gone away in /var/www/html/wp-includes/wp-db.php on line 1531

Warning: mysqli_real_connect(): (HY000/2006): MySQL server has gone away in /var/www/html/wp-includes/wp-db.php on line 1531

It would appear the mysql plugin is too old to support authenticating with the latest version of mysql? I had to bump down the auth to the old 5.x methodology to get this to work.

Excerpt from phpinfo();

mysqlnd

mysqlnd => enabled
Version => mysqlnd 5.0.12-dev - 20150407 - $Id: 38fea24f2847fa7519001be390c98ae0acafe387 $

It seems pretty old to me?

[jonmchan]

According to docs: http://php.net/manual/en/ref.pdo-mysql.php

MySQL 8

When running a PHP version before 7.1.16, or PHP 7.2 before 7.2.4, set MySQL 8 Server's default password plugin to mysql_native_password or else you will see errors similar to The server requested authentication method unknown to the client [caching_sha2_password] even when caching_sha2_password is not used.

This is because MySQL 8 defaults to caching_sha2_password, a plugin that is not recognized by the older PHP (mysqlnd) releases. Instead, change it by setting default_authentication_plugin=mysql_native_password in my.cnf. The caching_sha2_password plugin will be supported in a future PHP release. In the meantime, the mysql_xdevapi extension does support it.

PHP Version on the image should support it?

$ php --version
PHP 7.2.8 (cli) (built: Jul 21 2018 07:52:06) ( NTS )

[wglambert]

It would appear the mysql plugin is too old to support authenticating with the latest version of mysql?

Right, you can use an older version if you want the default_authentication_plugin by default, or set it as such in mysql through the my.cnf
If you want your supported version of PHP to use sha_2 then PHP mentions this plugin provides that.

Given that PHP says the sha2 authentication method will be supported in a future release, we don't necessarily try to provide features or functionality that upstream doesn't.

[jonmchan]

7.2.8 > 7.2.4, shouldn't version 7.2.8 be a version that works with mysql8?

[wglambert]

If by "works with mysql8" you mean "supports sha2 by default" then no, it needs an extension for that as they state on the webpage you linked

The caching_sha2_password plugin will be supported in a future PHP release.
In the meantime, the mysql_xdevapi extension does support it.

Here are some resources I found talking about php and mysql 8:
https://stackoverflow.com/questions/49083573/php-7-2-2-mysql-8-0-pdo-gives-authentication-method-unknown-to-the-client-ca
https://github.com/phpmyadmin/phpmyadmin/issues/14220
https://github.com/laradock/laradock/issues/1392

[wglambert]

Seems that PHP just fixed default authentication for MYSQL8 https://github.com/php/php-src/commit/d6e81f0bfd0cb90586dd83d4fd47a4302605261a
it doesn't show up in the changelog

Heres the bug report for it https://bugs.php.net/bug.php?id=76243

Going to close since this seems resolved and is also upstream's domain

[Flimm]

Interesting that the error message contains a typo ("respose" instead of "response"). This made me assume that the error was from my code instead of from MySQL or the MySQL plugin directly.