in libraries/ceph_chef_helper.rb [797:813]
def ceph_chef_secure_password_alphanum_upper(len = 20)
alphanum_upper = [*'0'..'9']
alphanum_upper += [*'A'..'Z']
raw_pw = ''
while raw_pw.length < len
raw_pw << ::OpenSSL::Random.random_bytes(1).gsub(/\W/, '')
end
pw = ''
while pw.length < len
pw << alphanum_upper[raw_pw.bytes.to_a[pw.length] % alphanum_upper.length]
end
pw
end