I want to Provide 'Yes' automatically or Ignore it and proceed in a SECURE way, when the below statement comes during execution of my Expect Shell script?.
#!/usr/bin/expect
spawn ssh $user@$host
The authenticity of host 'abcdef (10.566.1.98)' can't be established. RSA key fingerprint is jk:94:ba:93:0b:eb:ff:df:ea:gh:hj:23:3c:hj:9c:be. Are you sure you want to continue connecting (yes/no)?
It's possible to avoid this question and accept all incoming keys automaticatilly by using ssh client option StrictHostKeyChecking
set to no
(default setting is ask
, which results in that question):
ssh -o StrictHostKeyChecking=no "$user@$host"
However, note that it would be hardly any secure, as you're basically accepting connect with everyone who may act as a given host. The only secure way to avoid question is to pre-distribute host public keys to clients, i.e. in form of pre-generated known hosts file, which can be used in some way like that:
ssh \
-o UserKnownHostsFile=PATH_TO_YOUR_KNOWN_HOSTS_FILE \
-o StrictHostKeyChecking=yes "$user@$host"
This way you'll avoid the question if the check fails, and ssh will result in non-zero exit status.