tools: download from url: add option to allow overriding existing files

[pve-common.git] / src / PVE / Tools.pm

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index 9046b4f2c4ef7953b60581024b1d3b1f4a42398a..465c338375d8bc652f4d32ecc75e6b4b37a6e39d 100644 (file)
--- 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";
        }
     }