Mongodn database is connected in the form of URL

url Format ：  【 Be careful ：IP The address can be changed to the domain name 】

mongodb:// user name : password @IP: Port number / Database name ?replicaSet=1234&authSource=admin

In the form of clusters url Format ：

mongodb:// user name : password @IP: Port number ,IP: Port number ,IP: Port number / Database name ?replicaSet=1234&authSource=admin

MongoDB Connect URL：  【 In the environment variables 】

MONGODN_HOST_URL( It's a random name , Just match it )=mongodb:// user name : password @IP: Port number / Database name ?replicaSet=1234&authSource=admin