OpenSSH filling up auth.log due to missing ed25519 host key file

[Rene Soto]

In a 6.1 Fuel environment based on Ubuntu, it appears that OpenSSH logs the following message every time an SSH connection is attempted on a controller:
Could not load host key: /etc/ssh/ssh_host_ed25519_key

While SSH connections are successful, this message is silently logged to /var/log/auth.log due to the ed25519 host key file missing in /etc/ssh. In larger environments, it has even generated 100,000+ message in a one-hour timeframe.

This issue is resolved by running "ssh-keygen -A" which generates the host keys that do not exist, however, this is something that has to be done manually at this time.

[Alex Schultz (alex-schultz)]

Confirmed this error message happens when you ssh to an ubuntu machine.

<35>Aug 13 21:37:52 node-1 sshd[10269]: error: Could not load host key: /etc/ssh/ssh_host_ed25519_key

So if there is a constant stream of ssh port checks (ie from monitoring), this may fill logs.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/212809

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/212809
Committed: https://git.openstack.org/cgit/stackforge/fuel-library/commit/?id=5deba2244432de11267965017a2b90a079dbad82
Submitter: Jenkins
Branch: master

commit 5deba2244432de11267965017a2b90a079dbad82
Author: Alex Schultz <email address hidden>
Date: Thu Aug 13 16:55:55 2015 -0500

    Ensure all ssh host keys are generated

    In order to prevent address logging issues when some host ssh keys are
    missing, we need to run a ssh-keygen -A as part of our ssh server setup
    on Ubuntu.

    Change-Id: I7e91798b638b9726cccaf395e8219ecb31d69e82
    Closes-Bug: 1484693

[Bartłomiej Piotrowski (bpiotrowski)]

Verified on 7.0-259.

root@node-1:~# ls -1 /etc/ssh/*_key{,.pub}
/etc/ssh/ssh_host_dsa_key
/etc/ssh/ssh_host_dsa_key.pub
/etc/ssh/ssh_host_ecdsa_key
/etc/ssh/ssh_host_ecdsa_key.pub
/etc/ssh/ssh_host_ed25519_key
/etc/ssh/ssh_host_ed25519_key.pub
/etc/ssh/ssh_host_key
/etc/ssh/ssh_host_key.pub
/etc/ssh/ssh_host_rsa_key
/etc/ssh/ssh_host_rsa_key.pub

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/6.1
Review: https://review.openstack.org/223073

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/223073
Committed: https://git.openstack.org/cgit/stackforge/fuel-library/commit/?id=74691feb0870f20c695630c4f90be546b46cba3a
Submitter: Jenkins
Branch: stable/6.1

commit 74691feb0870f20c695630c4f90be546b46cba3a
Author: Alex Schultz <email address hidden>
Date: Thu Aug 13 16:55:55 2015 -0500

    Ensure all ssh host keys are generated

    In order to prevent address logging issues when some host ssh keys are
    missing, we need to run a ssh-keygen -A as part of our ssh server setup
    on Ubuntu.

    Change-Id: I7e91798b638b9726cccaf395e8219ecb31d69e82
    Closes-Bug: 1484693
    (cherry picked from commit 5deba2244432de11267965017a2b90a079dbad82)

[Vitaly Sedelnik (vsedelnik)]

Reassigned to Alexey Khivin to create release notes entry for MOS 6.1 MU 3