Mysql password can be supplied via `MYSQL_PASSWORD_FILE` which points to a file containing the Mysql password. This would typically be `/run/secrets/mysql-password`, where `mysql-passwrd` is a Docker secret containing the password.
S3 secret access key can be supplied via `S3_SECRET_ACCESS_KEY_FILE`, which points to a file containing the secret access key. This would typically be `/run/secrets/s3-secret-access-key`, where `s3-secret-access-key` is a Docker secret containing the secret access key.