Proposal: add certificate expiration metrics
I'd like to propose new metric to monitor certificates expiration.
Thanks for the "FAB-17000: Warn when certificates are about to expire", but this will not work in our case.
At a moment we have 4 different fabric environments, setted up at the different time and placed in different kubernetes clusters.
We need 100% accurate data when certificates are going to expire, better with different severities.
So, pretty simple (from my view) solution: every time any part of hyperledger fabric reads any certificate - it creates or updates metric with issuer and certificate CN as a labels and not_after as a value, in unixtime. Based on this data companies can setup any notification flow they need.