Migrate issue on linuxserver/mariad container: "'Specified key was too long; max key length is 767 bytes"

Hi Docker support team,

I’m trying to run my django application with mariadb on the Raspberry Pi4 using docker compose.
I wanted to install mariadb (I installed mariadb on the Pi successfully without using docker before), but it says mariadb doesn’t support armv7 when I tried to pull mariadb image. So I used linuxserver/mariadb.

I built the image and created network and containers(django and db container) successfully. The containers are running without any issue.
However, I met the following error while migrating the db.

Through some googling, I knew the character encoding of the db should be set to utf8 to fix it.
In order to fix this issue, I tried two ways in the following link.

–The first way: Adding a command for utf-8 setting
In this case, my docker-compose.yml file is above.
However, this way didn’t work and I got the same error. Of course, I rebuilt the image and container before trying this.

  • -The second way: Mounting a custom cnf file as a volume

In this case, the docker-compose.yml file is above
In fact, I’m not sure if the declaration of the volume of the mycustom.cnf is correct. But if I add the volume for mycustom.cnf without any declaration, then I get an error.
The mycustom.cnf file is in the project root directory(docker-compose.yml file is also in the root directory).
Here is mycustom.cnf.
character-set-server = utf8
collation-server = utf8_unicode_ci

Anyway, the second way also didn’t work as well.
I tried several other ways to fix this issue, but they also didn’t work.

How can I fix this error? I’m struggling with this issue for three days.
I really hope you get back to me with the best solution as soon as possible.

Thanks in advance.