How to update CoreOS cloud-config?

@bgrayburn you can update ssh keys without doing anything crazy: https://github.com/coreos/init/blob/master/bin/update-ssh-keys

I have a script that I use to push them out across my fleet:

$ cat fleetctl-inject-ssh.sh
#!/bin/bash -x

# Usage:
#   cat public.key | fleetctl-inject-ssh.sh keyname

name=$1
if [ -z $name ]; then
  echo "Provide a name for the injected SSH key"
  exit 1
fi

shift 1

pubkey=$(cat)

for machine in $(fleetctl -strict-host-key-checking=false $@ list-machines --no-legend --full | awk '{ print $1;}'); do
  fleetctl  -strict-host-key-checking=false $@ ssh $machine "echo '${pubkey}' | update-ssh-keys -a $name -n"
done

so to run you could do something like:

echo 'THE_CONTENTS_OF_PUBKEY' |  ./fleetctl-inject-ssh.sh <SOME_INTELLIGENT_NAME_FOR_KEY>

or

cat <PUBKEY> | ./fleetctl-inject-ssh.sh <SOME_INTELLIGENT_NAME_FOR_KEY>

You can find the cloud-config in :

• /var/lib/coreos-install/user_data for baremetal
• /var/lib/coreos-vagrant/vagrant-user-data for vagrant

update it, reboot, if no error, the new configuration should be done. I don’t know if it’s the good way but it seems to work.

Has anyone able to update the user-data without using @Wallner solution?