How to make advanced ruleset to crack passwords

Hi! I want to make hashcat only test passwords that contain at least 1 digit, 1 uppercase letter and 1 lowercase letter and these can be in any position. The password must be at least 8 characters long. I do not want to use a wordlist for this job as the file size would be too big so I would like the passwords to be generated on the go. I have looked at the documentation but was unable to find anything regarding my issue. 

So is there anyway to achieve this?
Thanks.