Comment 0 for bug 1781039

Per documentation at https://wiki.ubuntu.com/GoogleComputeEngineSSHKeys ssh keys for cloudinit and ubuntu users should both be added to the 'ubuntu' users authorized_keys file.

This works fine in Xenial (16.04) and higher, but doesn't work for Trusty (14.04).

[REPRODUCE]

# create a file that contains ssh public keys

$ cat googlekeys
test:ssh-rsa <one example key> <email address hidden>
ubuntu:ssh-rsa <a second example key> <email address hidden>
cloudinit:ssh-rsa <a third example key> <email address hidden>

# create an ubuntu 14.04 instance

gcloud compute instances create ubuntu1404cloudinit --image-family ubuntu-1404-lts --image-project ubuntu-os-cloud --metadata-from-file=ssh-keys=googlekeys --metadata=block-project-ssh-keys=True

# create an ubuntu 16.04 instance

gcloud compute instances create ubuntu1604cloudinit --image-family ubuntu-1604-lts --image-project ubuntu-os-cloud --metadata-from-file=ssh-keys=googlekeys --metadata=block-project-ssh-keys=True

Notice that the ubuntu user in the ubuntu 14.04 instance contains no keys from cloud-init (the keys there are added by the google daemon):

$ sudo cat /home/ubuntu/.ssh/authorized_keys
# Added by Google
ssh-rsa <the second example key but added by google daemon> <email address hidden>

In 16.04,

$ sudo cat /home/ubuntu/.ssh/authorized_keys
ssh-rsa <the third example key added by cloud-init> <email address hidden>
ssh-rsa <the second example key added by cloud-init> <email address hidden>
# Added by Google
ssh-rsa <the second example key added by the google daemon> <email address hidden>

[EXPECTED BEHAVIOR]

The ubuntu and cloudinit keys in metadata should be added to the ubuntu user by cloud-init.