require 'base64'
require 'digest/sha1'
transformation = "c_scale,q_auto,dpr_auto,f_auto,w_auto:100:330"
public_id = "local-env/2020-11/crop-sample-2x_uhl18c.jpg"

account_name = "ACCOUNT_NAME"
secret = "SECRET"

to_sign = ([transformation, public_id]).join("/")
p to_sign
sh1 = Digest::SHA1.digest(to_sign + secret)
p sh1
signature = 's--' + Base64.urlsafe_encode64(sh1)[0,8] + '--'
url = 'https://res.cloudinary.com/' + account_name + '/image/upload/' + ([signature, to_sign]).join("/")
p url

p signature