WordPress Docker container on Elastic Beanstalk not connecting to MariaDB container

Question

I'm trying to generate a multi-container Docker WordPress deployment on Beanstalk by running a Dockerrun.aws.json file from the EB CLI. Here's my Dockerrun:

{
"AWSEBDockerrunVersion": 2,
"containerDefinitions": [
    {
        "name": "mariadb",
        "image": "mariadb:latest",
        "essential": true,
        "memory": 128,
        "portMappings": [
            {
                "hostPort": 3306,
                "containerPort": 3306
            }
        ],
        "environment": [
            {
                "name": "MYSQL_USERNAME",
                "value": "root"
            },
            {
                "name": "MYSQL_PASSWORD",
                "value": "password"
            },
            {
                "name": "MYSQL_DB_NAME",
                "value": "wordpress"
            }
        ]
    },
    {
        "name": "wordpress",
        "image": "wordpress",
        "essential": true,
        "memory": 128,
        "portMappings": [
            {
                "hostPort": 80,
                "containerPort": 80
            }
        ],
        "links": [
            "mariadb"
        ],
        "environment": [
            {
                "name": "MYSQL_ROOT_PASSWORD",
                "value": "password"
            }
        ]
     }
  ]
}

The Beanstalk environment launches properly and I can browse to the endpoint and begin the WordPress configuration, but it never connects to the MariaDB. When I SSH into the host instance, I can see that both the WordPress and MariaDB containers are launching over and over again - and failing. There are multiple mariadb-* log files in /var/log/containers/ on the host, all with this text:

error: database is uninitialized and password option is not specified 
You need to specify one of MYSQL_ROOT_PASSWORD, 
MYSQL_ALLOW_EMPTY_PASSWORD and MYSQL_RANDOM_ROOT_PASSWORD

My guess is that the password isn't making it through. Any ideas why not? Thanks

Answer 1

The solution was simple. The syntax I was using was wrong. I originally used:

"name": "MYSQL_DB_NAME"

But it should have been:

"name": "MYSQL_DATABASE"