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#!/usr/bin/env perl
# Common library for havirt. Basically, just a place to put things which may be used by any
# part of havirt. More for organizations purposes.
# Copyright 2024 Daily Data, Inc.
#
# Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following
# conditions are met:
#
# Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
# Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the distribution.
# Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived
# from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
# NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
# THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# v0.0.1 20240602 RWR
# Initial setup
package havirt;
use warnings;
use strict;
use Data::Dumper qw(Dumper); # Import the Dumper() subroutine
# define the version number
# see https://metacpan.org/pod/release/JPEACOCK/version-0.97/lib/version.pod
use version;
our $VERSION = version->declare("1.0.0");
use Exporter;
our @ISA = qw( Exporter );
our @EXPORT = qw(
&readDB &writeDB
&report &scan
&makeCommand &forceScan
&executeAndWait
&findDomain
&diffArray
);
# read a DB file (just a YAML)
# if $lock is set, will create a "lock" file so other processes will
# not try to write to it. Using custom code as flock is automagically
# release when the file is read
sub readDB {
my $lock = shift;
my $lockFileName = "$main::statusDBName.lock";
my $lockTime = 5; # maximum time to wait for lock to clear
# wait for lock to clear if it exists, if we are wanting a lock
# and we have tried it for $locktime iterations
while ( $lock && -f $lockFileName && $lockTime-- ) {
sleep 1; # wait one second, then try again
}
if ( $lock ) {
die "Something has $main::statusDBName locked, aborting\n" if -f $lockFileName;
`touch $lockFileName`;
}
my $yaml = YAML::Tiny->new( {} );
if ( -f $main::statusDBName ) {
$yaml = YAML::Tiny->read( $main::statusDBName );
}
$main::statusDB = $yaml->[0];
}
sub writeDB {
my $yaml = YAML::Tiny->new( $main::statusDB );
$yaml->write( $main::statusDBName );
unlink "$main::statusDBName.lock" if -f "$main::statusDBName.lock"; # release any lock we might have on it
}
sub report {
if ( $main::reportFormat eq 'tsv' ) {
return &report_tsv( @_ );
} else {
return &report_screen( @_ );
}
}
sub report_tsv {
my ( $header, $data ) = @_;
my @output;
push @output, join( "\t", @$header );
for( my $line = 0; $line < @$data; $line++ ) {
push @output, join( "\t", @{$data->[$line]} );
} # for
return join( "\n", @output ) . "\n";
}
sub report_screen {
my ( $header, $data ) = @_;
my @output;
my @widths;
my $column;
my $row;
# First, initialize by using the length of the headers
for ( $column = 0; $column < @$header; $column++ ) {
@widths[$column] = length( $header->[$column] );
}
# now, go through all data in each row, for each column, and increment the width if it is larger
for ( $row = 0; $row < @$data; $row++ ) {
for ( $column = 0; $column < @$header; $column++ ) {
$widths[$column] = length( $data->[$row][$column] )
if length( $data->[$row][$column] ) > $widths[$column];
} # for column
} # for row
# actually do the print now
my @format;
for ( $column = 0; $column < @widths; $column++ ) {
push ( @format, '%' . $widths[$column] . 's' );
}
my $format = join( ' ', @format ) . "\n";
my $output = sprintf( $format, @$header );
for ( $row = 0; $row < @$data; $row++ ) {
$output .= sprintf( $format, @{$data->[$row]} );
} # for row
return $output;
}
# scans a node to determine which domains are running on it
sub getDomainsOnNode {
my $node = shift;
my @nodeList = grep { /^\s*\d/ } `ssh $node 'virsh list'`;
for ( my $i = 0; $i < @nodeList; $i++ ) {
if ( $nodeList[$i] =~ m/\s*\d+\s*([^ ]+)/ ) {
$nodeList[$i] = $1;
}
}
my %hash = map{ $_ => time } @nodeList;
return \%hash;
}
# find node a domain is on
# first parameter is the domain name
# rest of @_ is list of nodes to search
# if no nodes passed in, will search all known nodes
# returns first node found with the domain, or an empty string if not found
# possibly not being used??
sub findDomain {
my $domainName = shift;
my @node = @_;
my $foundNode = '';
&readDB();
unless ( @node ) {
@node = keys %{$main::statusDB->{'node'} };
print "findDomain, nodes = " . join( "\t", @node ) . "\n" if $main::DEBUG > 1;
}
foreach my $thisNode ( @node ) {
my $output = `ssh $thisNode 'virsh list'`;
print "findDomain, $thisNode list =\n" . $output . "\n" if $main::DEBUG > 1;;
return $thisNode if ( $output =~ m/$domainName/ );
}
return '';
}
# check one or more nodes and determine which domains are running on them.
# defaults to everything in the node database, but the -t can have it run on only one
# this is the function that should be run every few minutes on one of the servers
sub scan {
if ( -f $main::lastScanFileName && ! $main::force ) {
my $lastScan = time - ( stat( $main::lastScanFileName ) ) [9];
return "Scan was run $lastScan seconds ago\n" unless $lastScan > $main::minScanTimes;
}
`touch $main::lastScanFileName`;
&main::readDB(1);
print Dumper( $main::statusDB->{'nodePopulation'} ) if $main::DEBUG > 2;
my @targets;
if ( $main::targetNode ) {
push @targets, $main::targetNode;
} else {
@targets = keys %{$main::statusDB->{'node'}};
}
print "Scanning " . join( "\n", @targets ) . "\n" if $main::DEBUG;
foreach my $node (@targets) {
$main::statusDB->{'nodePopulation'}->{$node}->{'running'} = &getDomainsOnNode( $node );
$main::statusDB->{'nodePopulation'}->{$node}->{'lastchecked'} = time;
foreach my $domain ( keys %{$main::statusDB->{'nodePopulation'}->{$node}->{'running'}} ) {
# make sure there is an entry for all of these domains
$main::statusDB->{'virt'}->{$domain} = {} unless exists( $main::statusDB->{'virt'}->{$domain} );
}
print Dumper( $main::statusDB->{'nodePopulation'}->{$node} ) if $main::DEBUG > 2;
}
&main::writeDB();
return "Node(s) updated\n";
}
# makes the command that will be run on a node
# Created as a sub so we can change format easily
sub makeCommand {
my ( $node, $command ) = @_;
return "ssh $node '$command'";
}
# force a node scan, even if time has not expired
sub forceScan {
my $save = $main::force;
$main::force = 1;
&main::scan();
$main::force = $save;
}
# executes command $command, then repeatedly runs virsh list
# on $scanNode, grep'ing for $scanDomain
# $condition is 1 (true) or 0 (false)
sub executeAndWait {
my ( $command, $scanNode, $scanDomain, $condition ) = @_;
my $waitSeconds = 5; # number of seconds to wait before checking again
my $maxIterations = 60 / $waitSeconds; # maximum number of tries
print "Running [$command], then waiting $waitSeconds to check if complete\n" if $main::DEBUG;
`$command`;
my $waitCommand = &makeCommand( $scanNode, "virsh list | grep $scanDomain" );
my $output = '';
do {
return 0 unless ( $maxIterations-- ); # we've waited too long, so probably not working
print '. ';
sleep 5;
$output = `$waitCommand`;
print "[$waitCommand] returned [$output]\n" if $main::DEBUG > 1;
} until ( $condition ? $output : !$output );
return 1; # made it successful
}
# find the differences between two arrays (passed by reference)
# first sorts the array, then walks through them one by one
# @$arr1 MUST be larger than @$arr2
sub diffArray {
my ( $arr1, $arr2 ) = @_;
my @result;
@$arr1 = sort @$arr1;
@$arr2 = sort @$arr2;
my $i=0;
my $j=0;
while ( $i < @$arr1 ) {
if ( $arr1->[$i] eq $arr2->[$j] ) {
$i++;
$j++;
} elsif ( $arr1->[$i] lt $arr2->[$j] ) {
push @result, $arr1->[$i];
$i++;
} else {
push @result, $arr2->[$j];
$j++;
}
}
return \@result;
}