[pve-devel] applied: [PATCH] tools: download from url: add option to allow overriding existing files

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
---

allows for slightly nicer UX and drops the confusing special case of
"always allow overwriting if no checksum algorithm was passed".

 src/PVE/Tools.pm | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index 9046b4f..465c338 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -1842,6 +1842,7 @@ sub safe_compare {
 
 
 # opts is a hash ref with the following known properties
+#  allow_overwrite - if 1, overwriting existing files is allowed, use with care. Default to false
 #  hash_required - if 1, at least one checksum has to be specified otherwise an error will be thrown
 #  http_proxy
 #  https_proxy
@@ -1862,17 +1863,22 @@ sub download_file_from_url {
 
     print "downloading $url to $dest\n";
 
-    if (-f $dest && $checksum_algorithm) {
-	print "calculating checksum of existing file...";
-	my $checksum_got = get_file_hash($checksum_algorithm, $dest);
+    if (-f $dest) {
+	if ($checksum_algorithm) {
+	    print "calculating checksum of existing file...";
+	    my $checksum_got = get_file_hash($checksum_algorithm, $dest);
 
-	if (lc($checksum_got) eq lc($checksum_expected)) {
-	    print "OK, got correct file already, no need to download\n";
-	    return;
-	} else {
-	    # we could re-download, but may not be safe so just abort for now..
-	    print "\n";  # the front end expects the error to reside at the last line without any noise
-	    die "checksum mismatch: got '$checksum_got' != expect '$checksum_expected', aborting\n";
+	    if (lc($checksum_got) eq lc($checksum_expected)) {
+		print "OK, got correct file already, no need to download\n";
+		return;
+	    } elsif ($opts->{allow_overwrite}) {
+		print "checksum mismatch: got '$checksum_got' != expect '$checksum_expected', re-download\n";
+	    } else {
+		print "\n";  # the front end expects the error to reside at the last line without any noise
+		die "checksum mismatch: got '$checksum_got' != expect '$checksum_expected', aborting\n";
+	    }
+	} elsif (!$opts->{allow_overwrite}) {
+	    die "refusing to override existing file '$dest'\n";
 	}
     }
 
-- 
2.30.2