Wordpress Docker: Error establishing DB connection (MYSQL)

Question

I have been watching this before. Moving Wordpress site to Docker: Error establishing DB connection

My Linux is centos VM, I try to create WordPress and MySQL(5.6~8). It will be created but I can not connect DB.

This is my command (using swarm).

docker swarm init --advertise-addr=192.168.50.31
docker swarm join --token -secret token- 192.168.50.31:2377

docker network create -d overlay demo



docker service create --name wordpress 
-p 80:80 --env WORDPRESS_DB_PASSWORD=root 
--env WORDPRESS_DB_HOST=mysql 
--network demo  wordpress

docker service create --name mysql 
--env MYSQL_ROOT_PASSWORD=root --env 
MYSQL_DATABASE=wordpress --network demo 
--mount 
type=volume,source=mysql-data,destination=/var/lib/mysql mysql:5.6

I try to search it why. But did not find the answer.

look into this https://docs.docker.com/compose/wordpress/ – Adiii Nov 20 '19 at 06:45 — Adiii, Nov 20 '19 at 06:45
Why...I just success...thank anyway – MAX Nov 20 '19 at 06:50 — MAX, Nov 20 '19 at 06:50

score 0 · Answer 1 · edited Apr 30 '23 at 15:07

I think you cannot connect your two services because some variables are missing.

In your Mysql service, you need your database username. Same for WordPress, however, you also need your WordPress db name.

Here is what I mean:

docker service create --name mysql --env MYSQL_ROOT_PASSWORD=root --env MYSQL_DATABASE=wordpress --env MYSQL_USER=yourusername --network demo

And for your WordPress:

docker service create --name wordpress -p 80:80 --env WORDPRESS_DB_PASSWORD=root --env WORDPRESS_DB_HOST=mysql --env WORDPRESS_DB_USER=yourusername --env WORDPRESS_DB_NAME=wordpress --network demo wordpress

By the way, I think that you also have 2 different networks.

Wordpress Docker: Error establishing DB connection (MYSQL)

1 Answers1