docker wordpress container can’t connect to mysql container

I’m at a loss here as to not only why this isn’t working but how to further troubleshoot it. I’m new to docker, so could be something obvious, but I can’t find it. I did look over some other links here which could be considered “duplicate questions” and nothing helped.

My playground setup:

mysql container named: “db”
phpmyadmin container named: phpmyadmin
wordpress container named: domain-blog

All containers are in a bridge network docker0

At this stage I’m starting all containers individually, but I am ensuring the database is up and running prior to running wordpress.

The string to start the wordpress container:

docker run --name="domain-blog" -d 
-e WORDPRESS_DB_HOST=db:3306 
-e WORDPRESS_DB_USER=domain_user 
-e WORDPRESS_DB_PASSWORD=testedpassword 
-e WORDPRESS_DB_NAME=domain_blog 
-e WORDPRESS_TABLE_PREFIX=astring 
--network=docker0 
-p 8081:80 
--restart always 
wordpress

What I’ve tried:

I can log in as root with rootpassword from phpmyadmin navigating via hostip:8080.
I can log in as domain_user, using the testedpassword from phpmyadmin.
Confirmed I can add a new table when logged in as domain_user.
I have spun up an ubuntu container and installed network tools, can ping all containers.
I installed iputils-ping directly on the wordpress container and can ping db using ping db. Ping is hitting, but also confirmed that the db is resolving to the correct ip address.
cat wp-config.php shows that user, host(db:3306), password, and database are all being passed through as I’d expect.

I used phpmyadmin when I created the new user/password, database, and added permissions for the user to that database. The user is set to log in from %.

The error I’m getting on not being able to access the database is when trying to navigate to the blog via hostip:8081 Exact error: Error establishing a database connection

Answer

Solved it and feeling rather dumb about it, but in the spirit of education…

When I entered the username/password into mysql via phpmyadmin, the default in the admin interface is to use Caching sha2 authentication.

I reset the password using Native Mysql Authentication… It works no problem now.

Advertisement

Answer