Word press is not using default environment variables in docker container

[deekshith-elear]

Hi,
I'm using WORDPRESS_DB_HOST to provide my database host name as a environmental variable to my wordpress docker container. In My oldversion of docker image which is an year old it is able to work properly. now I want to migrate to 5.8 and getting database connection error. If I hardcode data of host it is working. else it is not fetching data.

Can anyone help me to fix this issue?

[wglambert]

What do the docker logs show for the error? And what's your docker-compose.yml look like