Files
server-config/modules/impermanence.nix

71 lines
1.6 KiB
Nix

{
config,
lib,
pkgs,
username,
service_configs,
inputs,
...
}:
{
imports = [
inputs.impermanence.nixosModules.impermanence
];
environment.persistence."/persistent" = {
hideMounts = true;
directories = [
"/var/log"
"/var/lib/systemd/coredump"
"/var/lib/nixos"
"/var/lib/systemd/timers"
# ZFS cache directory - persisting the directory instead of the file
# avoids "device busy" errors when ZFS atomically updates the cache
"/etc/zfs"
];
files = [
# Machine ID
"/etc/machine-id"
];
users.${username} = {
files = [
".local/share/fish/fish_history"
];
};
users.root = {
files = [
".local/share/fish/fish_history"
];
};
};
# Store SSH host keys directly in /persistent to survive tmpfs root wipes.
# This is more reliable than bind mounts for service-generated files.
services.openssh.hostKeys = [
{
path = "/persistent/etc/ssh/ssh_host_ed25519_key";
type = "ed25519";
}
{
path = "/persistent/etc/ssh/ssh_host_rsa_key";
type = "rsa";
bits = 4096;
}
];
# Enforce root ownership on /persistent/etc. The impermanence activation
# script copies ownership from /persistent/etc to /etc via
# `chown --reference`. If /persistent/etc ever gets non-root ownership,
# sshd StrictModes rejects /etc/ssh/authorized_keys.d/root and root SSH
# breaks while non-root users still work.
# Use "z" (set ownership, non-recursive) not "d" (create only, no-op on existing).
systemd.tmpfiles.rules = [
"z /persistent/etc 0755 root root"
];
}