Does sshd need ssh-agent on startup?

[Igor Bukanov]

Hello,

I use HostKeyAgent with my sshd from OpenSSH 7.1. I accidentally
discovered that if the agent is not started, then sshd complains:

Could not connect to agent "path-to-socket": No such file or directory
Could not load host key: path-to-dir-with-pubkeys/ssh_host_ed25519_key.pub

However, after that sshd proceeds to start normally. Moreover, when I
start the agent, then clients can connect to the server without any
problems. When I stop the agent, then sshd resets the connection. And
then starting the agent makes clients to connect again.

This behavior suits my setup very well as it means I do not need to
worry about ordering sshd to run after the agent is ready. Still, if
sshd really needs an agent only when a client connects, why it
complains on startup or even tries to get the host keys from it?

Regards, Igor