Add curacao backup stuff

curacao/backup/backup.sh

@@ -0,0 +1,83 @@
+#!/usr/bin/env bash
+
+set -euxo pipefail
+
+# Parse arguments
+function help {
+    echo "Usage: $0 [-h|-i] volume"
+    echo "Backup BTRFS subvolume on rapido to razmo."
+    echo
+    echo "Arguments:"
+    echo "  volume: Name of the subvolume to backup"
+    echo
+    echo "Options:"
+    echo "  -h: Display this help message."
+    echo "  -i: Don't fail if the receiving subvolume doesn't exist."
+}
+
+init=false
+while getopts "hi" OPTION
+do
+    case "$OPTION" in
+        h)
+            help
+            exit 0
+            ;;
+        i)
+            init=true
+            ;;
+        ?)
+            help
+            exit 2
+            ;;
+    esac
+done
+shift "$((OPTIND - 1))"
+
+if [ "$#" -ne 1 ]
+then
+    help
+    exit 2
+fi
+volume="$1"
+
+# Assertions
+[ -d "/mnt/rapido/${volume}" ]
+[ -d "/mnt/rapido/${volume}.bkp" ] || "$init"
+[ ! -d "/mnt/rapido/${volume}.new" ]
+[ -d "/mnt/razmo/${volume}.bkp" ] || "$init"
+[ -d "/mnt/razmo/${volume}" ] || "$init"
+[ ! -d "/mnt/razmo/${volume}.new" ]
+[ ! -d "/mnt/razmo/${volume}.snapshots" ]
+
+# Taking a snapshot of the running subvolume
+btrfs subvolume snapshot -r "/mnt/rapido/${volume}" "/mnt/rapido/${volume}.new"
+
+# Sending (the difference with) the last backup to the backup disk
+function error_handler() {
+    btrfs subvolume delete "/mnt/rapido/${volume}.new" || true
+    btrfs subvolume delete "/mnt/razmo/${volume}.new" || true
+}
+trap error_handler ERR
+if [ -d "/mnt/rapido/${volume}.bkp" ]
+then
+    btrfs send -p "/mnt/rapido/${volume}.bkp" "/mnt/rapido/${volume}.new" | btrfs receive /mnt/razmo
+else
+    btrfs send "/mnt/rapido/${volume}.new" | btrfs receive /mnt/razmo
+fi
+trap - ERR
+
+# Removing old backups and putting the new one in place
+[ ! -d "/mnt/rapido/${volume}.bkp" ] || btrfs subvolume delete "/mnt/rapido/${volume}.bkp"
+mv "/mnt/rapido/${volume}.new" "/mnt/rapido/${volume}.bkp"
+[ ! -d "/mnt/razmo/${volume}.bkp" ] || btrfs subvolume delete "/mnt/razmo/${volume}.bkp"
+mv "/mnt/razmo/${volume}.new" "/mnt/razmo/${volume}.bkp"
+
+# Create a writeable clone in case we need to boot on the HDD
+# Needs to move away then back the .snapshots folder
+[ ! -d "/mnt/razmo/${volume}/.snapshots" ] || mv "/mnt/razmo/${volume}/.snapshots" "/mnt/razmo/${volume}.snapshots"
+[ ! -d "/mnt/razmo/${volume}" ] || btrfs subvolume delete "/mnt/razmo/${volume}"
+btrfs subvolume snapshot "/mnt/razmo/${volume}.bkp" "/mnt/razmo/${volume}"
+[ ! -d "/mnt/razmo/${volume}.snapshots" ] || mv "/mnt/razmo/${volume}.snapshots" "/mnt/razmo/${volume}/.snapshots"
+
+sync