In case of a power loss shortly after first boot,
the host keys gernerated by ssh-keygen could exist
in the file system but have zero size, preventing
sshd from starting up.
This commit changes the behaviour to generate host
keys if the file either does not exist or has zero
size, fixing the problem on the next boot.
Thanks to @SuperSandro2000 for figuring this out.
On some systems bootctl cannot write the `LoaderSystemToken` EFI variable
during installation, which results in a failure to install the boot
loader. Upstream provides a flag (--graceful) to ignore such write failures -
this change exposes it as a configuration option.
As the exact semantics of this option appear to be somewhat volatile it
should be used only if systemd-boot otherwise fails to install.
Don't worry, it's is true by default. But I think this is important to
have because NixOS indeed shouldn't need Nix at run time when the
installation is not being modified, and now we can verify that.
NixOS images that cannot "self-modify" are a legitamate
use-case that this supports more minimally. One should be able to e.g. do a
sshfs mount and use `nixos-install` to modify them remotely, or just
discard them and build fresh ones if they are run VMs or something.
The next step would be to make generations optional, allowing just
baking `/etc` and friends rather than using activation scripts. But
that's more involved so I'm leaving it out.
I realized quite recently that running a test VM - as documented in the
manual - like
QEMU_NET_OPTS='hostfwd=tcp::8080-:80' ./result/bin/nixos-run-vms
doesn't work anymore on `master`. After bisecting I realized that the
introduction of a forward-port option[1] is the problem since it adds a
trailing comma even if no forwarding options are specified via
`virtualisation.forwardPorts`. In that case, the networking options
would look like `-netdev user,id=user.0,,hostfwd=tcp::8080-:80' which
confused QEMU and thus the VM refused to start.
Now, the trailing comma is only added if additional port forwards are
specified declaratively.
[1] b8bfc81d5b
The `$(</path/to/file)`-expansion appears verbatim in the cmdline of
`nextcloud-occ` which means that an unprivileged user could find
sensitive values (i.e. admin password & database password) by monitoring
`/proc/<pid>/cmdline`.
Now, these values don't appear in a command line anymore, but will be
passed as environment variables to `nextcloud-occ`.
