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#1 2018-04-04 19:02:51
- Slithery
- Administrator
- From: Norfolk, UK
- Registered: 2013-12-01
- Posts: 5,776
Perl help needed - linode-longview
Hi folks.
I currently maintain the https://aur.archlinux.org/packages/longview/ package in the AUR, it's a system monitoring client for the Linode VPS provider.
One of the metrics that it monitors is available system updates, at present this only supports apt, yum, and Gentoo - the aim of this post is to hopefully provide a patch that will add pacman support - I believe that this may be possible without any backend changes (although I don't mind being proved incorrect). Unfortunately, I have zero knowledge of Perl so am asking all of you for some input; as my aim is to get this upstreamed I don't want to embarrass myself with rookie mistakes. I also don't run any of these other OS's anywhere to compare package manager outputs (Arch only baby 
)
I'll be using a fork of the official Github repo to do development in - https://github.com/slithery/longview-dev
What I've made out so far...
The modules in Extras/Modules/Packages are responsible for gathering package information, creating a new pacman.pm using these as a template and rewriting it's functions to use pacman/checkupdates should be straightforward for someone who's used perl before and is aquainted with these other package managers. For reference the existing modules are posted below...
APT.pm
package Linode::Longview::DataGetter::Packages::APT;
=head1 COPYRIGHT/LICENSE
Copyright 2013 Linode, LLC. Longview is made available under the terms
of the Perl Artistic License, or GPLv2 at the recipients discretion.
=head2 Perl Artistic License
Read it at L<http://dev.perl.org/licenses/artistic.html>.
=head2 GNU General Public License (GPL) Version 2
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/
See the full license at L<http://www.gnu.org/licenses/>.
=cut
use strict;
use warnings;
use Linode::Longview::Util;
our $DEPENDENCIES = ['Processes.pm'];
our $next_run;
our $cache_touch_dt;
sub get {
my ( undef, $dataref ) = @_;
$logger->trace('Entering APT module');
if(check_running($dataref)){
$logger->debug('Another instance of apt-get is already running, skip package this pass');
$dataref->{INSTANT}->{Packages} = [];
return $dataref;
}
if(should_update()){
$logger->trace('Running apt-get update before reporting packages');
`apt-get -q update 2>/dev/null`;
}
my $new_touch_dt = (stat('/var/cache/apt/pkgcache.bin'))[9];
return $dataref if (defined($cache_touch_dt) && ($new_touch_dt == $cache_touch_dt));
$cache_touch_dt = $new_touch_dt;
$dataref->{INSTANT}->{Packages} = [];
my $held = 1;
if (open(APT, "echo n | apt-get -q -V upgrade 2>&1 |")) {
while (my $line = <APT>) {
chomp($line);
$held = 0 if ($line =~ m/^The following packages will be upgraded:/);
if ($line =~ m/^\s+(\S+)\s+\((\S+)\s+=>\s+(\S+)\)/) {
my $update = {};
$update->{name} = $1;
$update->{current} = $2;
$update->{new} = $3;
$update->{held} = $held;
push @{$dataref->{INSTANT}->{Packages}}, $update;
}
}
close(APT);
}
return $dataref;
}
sub should_update {
return 0 if((defined $next_run) && ($next_run > time));
$next_run = time + 86400; #Only actually hit the mirrors once every 24 hours.
return 1;
}
sub check_running {
my $dataref = shift;
return grep(m/Processes\.apt(?:-get|itude)/,keys %{$dataref->{LONGTERM}});
}
1;Gentoo.pm
package Linode::Longview::DataGetter::Packages::Gentoo;
=head1 COPYRIGHT/LICENSE
Copyright 2013 Linode, LLC. Longview is made available under the terms
of the Perl Artistic License, or GPLv2 at the recipients discretion.
=head2 Perl Artistic License
Read it at L<http://dev.perl.org/licenses/artistic.html>.
=head2 GNU General Public License (GPL) Version 2
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/
See the full license at L<http://www.gnu.org/licenses/>.
=cut
use strict;
use warnings;
use Linode::Longview::Util;
our $DEPENDENCIES = [];
our $next_run;
our @pkgs;
sub get {
my ( undef, $dataref ) = @_;
$logger->trace('Entering Gentoo module');
if(should_update()){
@pkgs = qx(VERSION='<version>,' eix -u '-*' --format '<category>/<name> <installedversions:VERSION> <bestslotupgradeversions:VERSION>\n');
}
$dataref->{INSTANT}->{Packages} = [
map {
my ($name, $current, $new) = $_ =~ /^([^ ]+) (.+?), (.+?),$/;
{
name => $name,
current => join(', ', split(/,/, $current)),
new => join(', ', split(/,/, $new))
}
} @pkgs
];
return $dataref;
}
sub should_update {
return 0 if((defined $next_run) && ($next_run > time));
$next_run = time + 1800; # Checking updates is expensive; only do it every 30 minutes
return 1;
}
1;YUM.pm
package Linode::Longview::DataGetter::Packages::YUM;
=head1 COPYRIGHT/LICENSE
Copyright 2013 Linode, LLC. Longview is made available under the terms
of the Perl Artistic License, or GPLv2 at the recipients discretion.
=head2 Perl Artistic License
Read it at L<http://dev.perl.org/licenses/artistic.html>.
=head2 GNU General Public License (GPL) Version 2
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/
See the full license at L<http://www.gnu.org/licenses/>.
=cut
use strict;
use warnings;
use Linode::Longview::Util;
our $DEPENDENCIES = [];
our $cache_touch_dt;
sub get {
my (undef, $dataref) = @_;
$logger->trace('Entering YUM module');
return $dataref if defined $cache_touch_dt && get_DB_touch_dt() == $cache_touch_dt;
my %u_pkgs = upgradable_pkgs();
if (!%u_pkgs){
$dataref->{INSTANT}->{Packages} = [];
$cache_touch_dt = get_DB_touch_dt();
return $dataref;
}
my %c_pkgs = current_pkgs();
$dataref->{INSTANT}->{Packages} = [
map {
{
name => $_,
current => $c_pkgs{$_},
new => $u_pkgs{$_}
}
}
keys %u_pkgs
];
$cache_touch_dt = get_DB_touch_dt();
return $dataref;
}
sub get_DB_touch_dt {
my $oldest = 0;
my $candidate;
for my $db (glob('/var/lib/rpm/__db.*')) {
$candidate = (stat($db))[9];
$oldest = $candidate if $oldest < $candidate;
}
return $oldest;
}
sub current_pkgs {
# yum wraps unless we fake a tty
my @pkg_list = qx(script -c 'yum --color=never list installed' /dev/null);
my %pkgs;
for my $pkg (@pkg_list) {
if ( $pkg =~ m/^(.*?)\s+(.*?)\s+@(.*)$/ ) {
$pkgs{$1} = $2;
}
}
return %pkgs;
}
sub upgradable_pkgs {
my @pkg_list = qx(yum check-update);
my %pkgs;
for my $pkg (@pkg_list) {
if ( $pkg =~ m/^(\S+\.\S+)\s+(\S+)\s+\S+$/ ) {
$pkgs{$1} = $2;
}
}
return %pkgs;
}
1;I'm also presuming that a patch will be needed for the file that does the OS detection and runs the appropriate module, although I've not been able to find exactly where this is yet.
I know that I'm asking alot, but any help would be much appreciated.
Slithery.
Edit - I'd also be interested in testers, if there's anyone else that has a Linode account then either let me know here or PM me and you can have a go before I upload it to the AUR if you don't mind.
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