yodaHedgehog: backup service

hosts/yodaHedgehog/host-specific.nix

@@ -48,17 +48,26 @@ in
     path = with pkgs; [
       # Provides `ssh`
       openssh
-      # Provides `awk`, `grep`, `sleep`, `printf`, `echo`, 'sendmail'
+      # Provides `readlink` (with support for parameter `-e`, required by `btrbk`)
+      coreutils
+      # Provides `awk`, `grep`, `sleep`, `printf`, `echo`, 'sendmail', `readlink` (without support for parameter `-e`)
       busybox
       # Provides `smtpctl`
       opensmtpd
+      # Provides `btrbk`
+      btrbk
+      # Provides `sudo` required by `btrbk`.
+      # Alternatively we could configure `btrbk` to use the "btrfs-progs" instead of the "btrfs-progs-sudo" backend. But the `btrbk` NixOS module has no option for this.
+      sudo
     ];
     # Script to execute as main process.
     script = ''
       set -eu -o pipefail
-      printf '%s\n' 'Starting backup script.'
+      #printf '%s\n' 'Starting backup script.'
 
-      # TODO: Backup: Pull BTRFS snapshots from ${backup-source}.
+      # Pull BTRFS snapshots from ${backup-source}.
+      btrbk -c /etc/btrbk/remote-backup-ssd.conf run
+      btrbk -c /etc/btrbk/remote-backup-hdd.conf run
 
       # Don't suspend as long as `${backup-source}:${stay-awake-file}` exists.
       while :; do
@@ -105,7 +114,7 @@ in
       #done
       sleep 15s
 
-      printf '%s\n' 'Finished backup script.'
+      #printf '%s\n' 'Finished backup script.'
       # Suspend to save power.
       systemctl suspend
     '';