From f8b5d82ac50697aab97703e57e1deccccd68d140 Mon Sep 17 00:00:00 2001
From: c0de <c0de@c0de.dev>
Date: Thu, 15 Dec 2022 22:52:52 -0600
Subject: [PATCH] Add ability to grow root partition + filesystem

---
 arch.pkr.hcl              | 14 ++++++++++++++
 files/grow-root           | 16 ++++++++++++++++
 files/grow-root.service   |  9 +++++++++
 scripts/install_system.sh |  4 ++--
 4 files changed, 41 insertions(+), 2 deletions(-)
 create mode 100644 files/grow-root
 create mode 100644 files/grow-root.service

diff --git a/arch.pkr.hcl b/arch.pkr.hcl
index 9d590a6..7a19bc0 100644
--- a/arch.pkr.hcl
+++ b/arch.pkr.hcl
@@ -82,6 +82,20 @@ build {
         destination = "/mnt/etc/systemd/network/99-dhcp-wildcard.network"
     }
 
+    provisioner "file" {
+        source = "files/grow-root"
+        destination = "/usr/local/sbin/grow-root"
+    }
+
+    provisioner "shell" {
+        inline = ["chmod +x /usr/local/sbin/grow-root"]
+    }
+
+    provisioner "file" {
+        source = "files/grow-root.service"
+        destination = "/etc/systemd/system/grow-root.service"
+    }
+
     provisioner "shell" {
         pause_before = "10s"
         scripts = [
diff --git a/files/grow-root b/files/grow-root
new file mode 100644
index 0000000..5329434
--- /dev/null
+++ b/files/grow-root
@@ -0,0 +1,16 @@
+#!/bin/bash
+
+dev="$(findmnt -nfvo SOURCE -- "/")"
+
+# If it's a partition, expand that first using growpart.
+if [ "$(lsblk -ndo TYPE -- "$dev")" = part ]; then
+	disk="$(lsblk -ndpo PKNAME -- "$dev")"
+	partnum="${dev##*[!0-9]}"
+	growpart "$disk" "$partnum" || { [ $? -ne 1 ] && exit 1; }
+fi
+
+# Inform kernel of new partition
+partprobe
+
+# Expand the filesystem.
+resize2fs -- "$dev" || exit 1
diff --git a/files/grow-root.service b/files/grow-root.service
new file mode 100644
index 0000000..d657857
--- /dev/null
+++ b/files/grow-root.service
@@ -0,0 +1,9 @@
+[Unit]
+Description=Grows the root partition and filesystem to match disk size
+
+[Service]
+Type=oneshot
+ExecStart=/usr/local/sbin/grow-root
+
+[Install]
+WantedBy=multi-user.target
diff --git a/scripts/install_system.sh b/scripts/install_system.sh
index d7df110..8deee3d 100644
--- a/scripts/install_system.sh
+++ b/scripts/install_system.sh
@@ -4,8 +4,8 @@ set -eux
 pacman-key --init
 
 # Install the system
-pacstrap -K /mnt base linux linux-firmware rng-tools grub sudo \
-    openssh ufw git vim python-pip nomad nomad-driver-nspawn
+pacstrap -K /mnt base linux linux-firmware rng-tools grub parted sudo \
+    openssh ufw git vim cloud-utils python-pip nomad nomad-driver-nspawn
 
 # Clear the cache
 arch-chroot /mnt pacman -Scc --noconfirm