Upgrade lightsail AWS Instance 16.04 LTS to 18.04 LTS

I rebooted without taking note of an sshd_config problem. Of course I was no longer able to ssh into the instance.

I reverted to an earlier snapshot

Started the process over again.

After the update finished and asked me to reboot I refused and then fixed my sshd_config file:

$ sudo sed -i ‘s/^Ciphers .*/Ciphers +aes256-cbc,aes192-cbc,aes128-cbc/’ /etc/ssh/sshd_config

Now I get:

Welcome to Ubuntu 18.04.2 LTS (GNU/Linux 4.15.0-1035-aws x86_64)

when I use ssh.

Which is great! I upgraded to Ubuntu 18.04 LTS and was able to head off a breaking change to SSH that happens with the upgrade.