env has higher precedence than file config and you can use under core to replace dot in env to replace file config

for example, to change config user

cred:
db:
user: admin
pwd:

you only need to set env "cred_db_user" or "cred.db.user"

then you can use archaius to get it, file config will be overwrite by env

archaius.Get("cred.db.user")

go build main.go
./main