Don't load the entire output of dumpreferences into memory.

It can get seriously big, so instead handle its output in stream mode.

1 files changed, 10 insertions, 6 deletions

diff --git a/files/reprepro/snapshots/time_based/tails-delete-expired-apt-snapshots b/files/reprepro/snapshots/time_based/tails-delete-expired-apt-snapshots
index 99be045..4d88a70 100755
--- a/files/reprepro/snapshots/time_based/tails-delete-expired-apt-snapshots
+++ b/files/reprepro/snapshots/time_based/tails-delete-expired-apt-snapshots
@@ -14,12 +14,13 @@ use warnings;
 
 use DateTime;
 use DateTime::Format::Mail;
+use English qw{-no_match_vars};
 use File::Basename;
 use File::Find::Rule;
 use File::Path qw(remove_tree);
 use File::Slurp;
 use Getopt::Long;
-use IPC::System::Simple qw(capturex runx);
+use IPC::System::Simple qw(runx);
 use List::MoreUtils qw(uniq);
 
 
@@ -68,12 +69,15 @@ my @snapshots_dirs = File::Find::Rule->directory()
 verbose_print("found snapshots directories: @snapshots_dirs\n");
 
 # Let's load once and for all references known by reprepro to see
-# which suites/snapshots are present there to see what needs removing:
+# which suites/snapshots are present there to see what needs removing
+# (use a shell pipeline to avoid loading the entire output of
+# dumpreferences into memory; we've seen it take no less than 7.5 GiB):
 my @reprepro_references =
-  uniq
-  map { (split / /, $_)[0] }
-  grep { $_ =~ /^s=/ }
-  capturex('reprepro', '-b', $archive_dir, 'dumpreferences');
+  `reprepro -b '$archive_dir' dumpreferences \\
+      | awk '/^s=/ {print \$1}' \\
+      | sort -u`;
+${^CHILD_ERROR_NATIVE} == 0
+    or die "E: Failed to load references: ${^CHILD_ERROR_NATIVE}";
 verbose_print("reprepro-known snapshot references:", (join "\n - ", '', @reprepro_references), "\n");
 
 my $now = DateTime->now();