Pull mirroring fails after some days because of ECDSA host key challenge
We are experiencing problems with mirroring forked repositories so that the fork is kept up to date. We set up mirroring with an ssh:// URL, pull, 'Detect Host Keys' option, ssh key authentication. After getting the ssh key, and adding it to my account, everything is fine, and the mirror works. But after, typically, a few days, everything stops, and we see messages like
"2:Fetching remote upstream failed: Failed to add the ECDSA host key for IP address '35.231.145.151' to the list of known hosts (/tmp/gitlab-shell-known-hosts20190811-23485-1i44u53). The project you were looking for could not be found. fatal: Could not read from remote repository.
Please make sure you have the correct access rights and the repository exists."
It seems as if dynamic IP addresses are being used, and when they change, the new address is not in the equivalent of ~/.ssh/known_hosts, but of course it could be something else.