script for slurping down tarballs for openbsd upgrades.

openbsd_59_to_60_upgrade.pl

#!/usr/bin/env perl

#
# Perl implementation of the guide at https://www.openbsd.org/faq/upgrade60.html
#
# Requires: Mojolicious
#

my $arch = "amd64";
my $rel = "6.0";
my $rel_source = "http://mirrors.mit.edu/pub/OpenBSD/$rel/$arch/";

use Mojo::UserAgent;
my $ua = Mojo::UserAgent;

#
# Download the release to /usr/rel
#

my $rnd = join('', split(/\./, $rel));
my @to_fetch = (
    (map { "$_$rnd.tgz" } qw/xshare xserv xfont xbase man game comp base/),
    qw/bsd bsd.mp bsd.rd/
);

system("mkdir -p /usr/rel/$rel");
chdir("/usr/rel/$rel");

print "Grabbing SHA256 for OpenBSD $rel...\n";
my $relsums = [split(/[\r\n]+/, $ua->get("$rel_source/SHA256")->res->body)];

print "Downloading release to /usr/rel/$rel...\n";

foreach my $file (@to_fetch) {
    unless (-e $file && cmp_sum($file)) {
        print "Downloading $file...\n";
        $ua->get("$rel_source/$file")->res->content->asset->move_to("$file");
        print "Downloaded\n";
    }
    if (cmp_sum("$file")) {
        print " + Checksum OK\n";
    } else {
        die "[fatal] sum for $file didn't match what was provided\n";
    }
}

print "Release $rel retrieved from $rel_source\n";

sub cmp_sum {
    my ($file) = @_;
    chomp my $output = `sha256 $file`;
    return scalar grep { /^\Q$output\E$/ } @$relsums;
}