From 1a3efadea29b99ab9522c1937dba202cc90fae28 Mon Sep 17 00:00:00 2001
From: Jiri Podivin <jpodivin@redhat.com>
Date: Thu, 31 Oct 2024 13:48:54 +0100
Subject: [PATCH] Newly downloaded archive is compared against existing files
 to ensure uniqueness

Signed-off-by: Jiri Podivin <jpodivin@redhat.com>
---
 .../templates/backup.sh.j2                    | 21 +++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/roles/log-detective-backup/templates/backup.sh.j2 b/roles/log-detective-backup/templates/backup.sh.j2
index d023ee3f5d..0f1e04b64e 100644
--- a/roles/log-detective-backup/templates/backup.sh.j2
+++ b/roles/log-detective-backup/templates/backup.sh.j2
@@ -1,5 +1,22 @@
-#! /bin/sh
+#!/bin/bash
+
+set -e
 
 basename=$(date +%s).tar.gz
+ld_backup_path="{{ ld_backup_path }}"
+backup_path=$ld_backup_path/$basename
 
-wget -O "{{ ld_backup_path }}/$basename" "{{ ld_dump_url }}"
+# Find last modified
+recent=$(find "$ld_backup_path" -type f -name "*tar.gz" -mtime -1 | sort | tail -n 1)
+
+wget -O "$backup_path" "{{ ld_dump_url }}"
+
+# Extract both and get hashes
+new=$(tar -xzf "$backup_path" -O | sha256sum)
+old=$(tar -xzf "$recent" -O | sha256sum)
+
+# Compare hashes
+if [ "$new" = "$old" ]; then
+  echo No changes since last backup, removing downloaded archive
+  rm "$recent"
+fi