docker hostname problem

When I create a container from mariadb image, setting hostname in docker run... prevents root account to login.

docker run (has problem)

docker run ...
docker run --detach \
  --name app-db \
  ...skip ...
  --hostname app-db-host \
  mariadb:10.6

• --hostname specified

Then, diving into the container using docker exec...

BASH
$ docker exec -it app-db bash
root@app-db-host:/#

When trying to log in mysql, valid username and password is not working because current hostname is not localhost, but app-db-host.

BASH
root@app-db-host:/# mysql -uroot -p
Enter password: (here valid password input)
Error 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

• localhost is required, but app-db-host

docker run with MARIADB_ROOT_HOST

If --hostname is specified in docker run..., this value should be specified to mariadb environment variable, too.

docker run ...
docker run --detach \
  --name app-db \
  --hostname app-db-host \
  --env MARIADB_ROOT_HOST=app-db-host \
  mariadb:10.6

• custom hostname app-db-host to root hostname in mariadb container

It creates a row in table user like this.

TXT
MariaDB [mysql]> select Host, User from user;
+-------------+-------------+
| Host | User |
+-------------+-------------+
| % | appuser |
| localhost | mariadb.sys |
| localhost | root |
| app-db-host | root |
+-------------+-------------+