ssh host key ed25519 not generated

[Frank]

Recent versions of OpenSSH (6.5 and higher) support ed25519 keys (next to DSA, RSA, ECDSA), but cloud-init doesn't generate them when missing.

This leads to the following error on recent distro's (eg: Debian 8 Jessie):

Apr 27 13:37:40 jessie sshd[1474]: error: Could not load host key: /etc/ssh/ssh_host_ed25519_key

Fix would be to support for the ed25519 key algorithm it to config/cc_ssh.py

From the OpenSSH 6.5 release notes: (http://www.openssh.com/txt/release-6.5)

 * ssh(1), sshd(8): Add support for Ed25519 as a public key type.
   Ed25519 is a elliptic curve signature scheme that offers
   better security than ECDSA and DSA and good performance. It may be
   used for both user and host keys.

[Frank (a-frank)]

sorry, only now found https://bugs.launchpad.net/cloud-init/+bug/1382118

This is a dup.