We have a node on the jenkins master (actually, several nodes) which connects using SSH and Manually trusted Key verification Strategy. We connect properly the slave to jenkins this way (A Sierra Mac Machine to be specific) Now, Sierra is way to old, we need to go with HighSierra. We don't just upgrade the machine, we totally wipe it, install HighSierra from scratch, install all what we need to this slave and connect it back with the same jenkins node (yet, no modification have been made on jenkins) We get an error when Jenkins try to connect to the node :
WARNING: The SSH key for this host is not currently trusted. Connections will be denied until this new key is authorised.
We try to fix SSH problem by connecting to master and ssh-keygen -R everything with that node, then connecting via ssh to the node and it works perfectly fine... But Jenkins is still unable to connect with the same message.
Now is the fun, We create a new node which is a copy of the first one and just save. No modification. It instantly connects.
So, I guess there is somewhere in jenkins where it stores the fingerprint (which changes after reinstallation) but I wasn't able to find out where.
For now, the workaround deleting the node and create a new one after reinstallation works fine, but I wonder if there is an other way to do it.
Something to say jenkins to forget the fingerprint?
Maybe the problem is elsewhere?
We use Jenkins 2.32.3 and our SSH Slaves Plugin is v1.15
Thanks for your enlightenment
