sudo: unable to resolve host (none)

[CWempe]

I am using the v1.1.x branch.

In my post-install.txt I have the following commands.

chroot /rootfs /bin/cat /dev/zero | chroot /rootfs /usr/bin/ssh-keygen -t rsa -b 4096 -q -N ""
chroot /rootfs /bin/cat /dev/zero | chroot /rootfs /usr/bin/sudo -u user1 /usr/bin/ssh-keygen -t rsa -b 4096 -q -N ""

Both commands create the key files I want. . But the second one shows a warning.

sudo: unable to resolve host (none)

And because of this issue, the comment in the key file is wrong ("(none)" instead of the real hostname).

How can I solve this issue?

[Mausy5043]

I don't understand why you would want to pipe /dev/zero into keygen

Here's a snippet from my post-install.txt:

# Here we regenerate all the host SSH keys
rm /rootfs/etc/ssh/ssh_host_*
chroot /rootfs /usr/bin/ssh-keygen -N "" -t rsa   -b 4096 -f /etc/ssh/ssh_host_rsa_key
chroot /rootfs /usr/bin/ssh-keygen -N "" -t dsa   -b 1024 -f /etc/ssh/ssh_host_dsa_key
chroot /rootfs /usr/bin/ssh-keygen -N "" -t ecdsa -b 521  -f /etc/ssh/ssh_host_ecdsa_key
chroot /rootfs /usr/bin/ssh-keygen -N "" -t ed25519       -f /etc/ssh/ssh_host_ed25519_key

This works fine for me.
Also not familiar with your second line. Could you explain what & why you're trying to accomplish there?

[CWempe]

I added /bin/cat /dev/zero, because ssh-keygen asks about the passphrase. This way I tell it to use no passphrase. ... in theory...

I will try again. :)

My second line creates a key for my personal user account "user1".

[CWempe]

I still get the "none" hostname. 😞

command in post-install.txt:

chroot /rootfs hostname

result:

(none)

Is this supposed to be this way? After the installation hostname shows the correct value.

/etc/hostnameand /etc/hostsare correct too, in the chroot enviroment.

Everything else is working fine! 👍 Thanks for your examples.

[kpfleming]

The installer script populates /etc/hostname and /etc/hosts in /rootfs with the hostname you've configured (or 'pi' as a default), so no, it's not supposed to be this way. However, it appears that on Linux these files are not used by the library function called by thehostname command, instead it calls the uname(2) function to get information from the kernel. Most likely ssh-keygen does the same thing. During the installation, the kernel has not been told what the machine's name is supposed to be.

To confirm this, add

hostname $hostname

in your post-install.txt file before the calls to ssh-keygen. If this solves the problem, a simple patch to the installer script will fix this permanently.

[CWempe]

I added your line hostname $hostnameand it worked!

I would be happy to test this and make a pull request if you tell me where this line of code should be placed. 😄

Between line 866 and 867? https://github.com/debian-pi/raspbian-ua-netinst/blob/v1.1.x/scripts/etc/init.d/rcS#L866

like:

# Tell the kernel what the hostname is supposed to be
hostname $hostname

[kpfleming]

I would put it between 847 and 848, the block that is already doing system-level hostname configuration.

[CWempe]

Ok. I created a PR.

https://github.com/debian-pi/raspbian-ua-netinst/pull/460