We were having this same error; after some troubleshooting it turned out that the 17.2.7
cephadm orchestrator's ssh client was choking on the keyboard-interactive
AuthenticationMethod (which is really PAM); Our sshd configuration was:
AuthenticationMethods keyboard-interactive publickey,keyboard-interactive
gssapi-with-mic,keyboard-interactive
Thus, cephadm was trying to use "publickey,keyboard-interactive"; publickey
would succeed, but the cephadm ssh client would close the connection as soon as a
follow-up keyboard-interactive method was attempted. Adding this to sshd_config for each
orchestrator seemed to fix it by using only publickey AuthenticationMethod for just the
cephadm orchestrators, but using the standard config for everybody else:
Match Address <cephadm IPv4>
# For some reason the 17.2.7 cephadm orchestrator
# chokes on keyboard-interactive (PAM)
# AuthenticationMethod; thus, exclude it.
AuthenticationMethods publickey
PermitRootLogin yes
Match Address <cephadm IPv6>
# For some reason the 17.2.7 cephadm orchestrator
# chokes on keyboard-interactive (PAM)
# AuthenticationMethod; thus, exclude it.
AuthenticationMethods publickey
PermitRootLogin yes
Cheers.