feat(scripts/liminix): add a basic liminix rebuild

This script requires manual efforts on the operator end not to fuck up
too hard.

This adds min-copy-closure and min-garbage-collect to the development
shell.

Signed-off-by: Ryan Lahfa <ryan@dgnum.eu>

default.nix

@@ -116,6 +116,10 @@ in
       pkgs.freeradius
       pkgs.picocom # for serial access
 
+      # Daemon-less copy closure for Liminix systems.
+      (pkgs.callPackage (sources.liminix + "/pkgs/min-copy-closure") { nix = pkgs.lix; })
+      # Daemon-less garbage collection for Liminix systems.
+      (pkgs.callPackage (sources.liminix + "/pkgs/min-collect-garbage") { nix = pkgs.lix; })
       (pkgs.callPackage ./lib/colmena {
         colmena = pkgs.callPackage "${sources.colmena}/package.nix" { };
       })

scripts/liminix-rebuild.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+# TODO: support automatic levitation when the rebuild counts does not fit in the target.
+# TODO: support preflight checks where we detect the environment we are booted in (this requires the levitation to write a special file).
+# TODO: use colmena to know the target host and focus on the node name.
+set -Eeuo pipefail
+
+ssh_command=${SSH_COMMAND-ssh}
+root_prefix=${ROOT_PREFIX-/}
+
+reboot="reboot"
+
+case "$1" in
+	"--no-reboot")
+		unset reboot
+		shift
+	;;
+	"--fast")
+		reboot="soft"
+		shift
+	;;
+	"--live")
+		echo "Root prefix changed from $root_prefix to /mnt"
+		root_prefix="/mnt"
+	;;
+esac
+
+target_host=$1
+shift
+
+if [ -z "$target_host" ] ; then
+    echo Usage: liminix-rebuild \[--no-reboot\] target-host params
+    exit 1
+fi
+
+if toplevel="$(nom-build $(colmena eval -E "{ nodes, ... }: nodes.$@.config.system.outputs.systemConfiguration" --instantiate))"; then
+    echo systemConfiguration $toplevel aimed at $root_prefix
+    sleep 3
+    min-copy-closure --root "$root_prefix" $target_host $toplevel
+    $ssh_command $target_host "$root_prefix/$toplevel/bin/install" "$root_prefix"
+    case "$reboot" in
+	reboot)
+	    $ssh_command $target_host "sync; source /etc/profile; reboot"
+	    ;;
+	soft)
+	    $ssh_command $target_host $toplevel/bin/restart-services
+	    ;;
+	*)
+	    ;;
+    esac
+else
+    echo Rebuild failed
+fi