Manifests are complex if you want a visual representation of whats happening look HERE. Also i have exposed the necessary environment variables to the container for a data base connection and application configuration. This not to be used directly to deploy the appliction yourself becuse there are sevral sevices not inclued in this. However it is a good refrance for copying.
# Application Enviroment Vars
PORT="3000"
ORIGNS="0.0.0.0"
DOMAIN="notesrus.nzdev.org"
HTTPS="true"
# Database Enviroment Vars
DATABASE_URL=<posgresql_uri>