title: git read only mirror repo that self updates
body: <p>I would like to create on-premise git read-only repo mirror of a cloud git repo that could be used for CI and similar needs that do not involve committing changes back. </p>
  
  <p>It seems creating git clone --mirror ... is the promising option - is there better?</p>
  
  <p>The element I am struggling with is the updates. There is an obvious solution of making a cron job to update on an interval, but I hope there is something smarter that I can do easily.</p>
  
  <p>I am wondering is it possible to hook a git fetch operation on (about to read event). With other words is it possible to hook in a git server detection of a request and make sure I fetch from the remote in the mirror before I respond.</p>
  
  <p>Or I should just add notifications on the remote to listen to and update on them?</p>
  
  <p>I am sorry, if this was answered, before - I am googling for a while now, without finding a decisive answer. </p>