#!/usr/bin/perl
# 
# This does shutdown-time tasks; migrate or stop servers, withdraw and power off the host.
# 
# Exit codes;
# 0 = Normal exit.
# 1 = Any problem that causes an early exit.
# 
# TODO: 
# 

use strict;
use warnings;
use Anvil::Tools;
require POSIX;
use Data::Dumper;

my $THIS_FILE           =  ($0 =~ /^.*\/(.*)$/)[0];
my $running_directory   =  ($0 =~ /^(.*?)\/$THIS_FILE$/)[0];
if (($running_directory =~ /^\./) && ($ENV{PWD}))
{
	$running_directory =~ s/^\./$ENV{PWD}/;
}

# Turn off buffering so that the pinwheel will display while waiting for the SSH call(s) to complete.
$| = 1;

my $anvil = Anvil::Tools->new();
$anvil->data->{switches}{'job-uuid'}     = "";
$anvil->data->{switches}{'power-off'}    = "";	# By default, the node is withdrawn. With this switch, the node will power off as well.
$anvil->data->{switches}{'stop-reason'}  = "";	# Optionally used to set 'system::stop_reason' reason for this host. Valid values are 'user', 'power' and 'thermal'.
$anvil->data->{switches}{'stop-servers'} = "";	# Default behaviour is to migrate servers to the peer, if the peer is up. This overrides that and forces hosted servers to shut down.
$anvil->Get->switches;
$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
	'switches::job-uuid'     => $anvil->data->{switches}{'job-uuid'},
	'switches::power-off'    => $anvil->data->{switches}{'power-off'},
	'switches::stop-reason'  => $anvil->data->{switches}{'stop-reason'},
	'switches::stop-servers' => $anvil->data->{switches}{'stop-servers'},
}});

$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 2, key => "log_0115", variables => { program => $THIS_FILE }});

# Make sure we're running as 'root'
# $< == real UID, $> == effective UID
if (($< != 0) && ($> != 0))
{
	# Not root
	print $anvil->Words->string({key => "error_0005"})."\n";
	$anvil->nice_exit({exit_code => 1});
}

$anvil->Database->connect();
$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 3, key => "log_0132"});
if (not $anvil->data->{sys}{database}{connections})
{
	# No databases, update the job, sleep for a bit and then exit. The daemon will pick it up and try 
	# again after we exit.
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 0, priority => "err", key => "error_0075"});
	sleep 10;
	$anvil->nice_exit({exit_code => 1});
}

# If we don't have a job UUID, try to find one.
if (not $anvil->data->{switches}{'job-uuid'})
{
	# Load the job data.
	$anvil->data->{switches}{'job-uuid'} = $anvil->Job->get_job_uuid({program => $THIS_FILE});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { "switches::job-uuid" => $anvil->data->{switches}{'job-uuid'} }});
}

# If we still don't have a job-uuit, go into interactive mode.
if ($anvil->data->{switches}{'job-uuid'})
{
	# Load the job data.
	$anvil->Job->clear();
	$anvil->Job->get_job_details();
	$anvil->Job->update_progress({
		progress         => 1,
		job_picked_up_by => $$, 
		job_picked_up_at => time, 
		message          => "message_0235", 
	});
	
	# Pull out the job data.
	foreach my $line (split/\n/, $anvil->data->{jobs}{job_data})
	{
		if ($line =~ /power-off=(.*?)$/)
		{
			$anvil->data->{switches}{'power-off'} = $1;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
				'switches::power-off' => $anvil->data->{switches}{'power-off'},
			}});
		}
		if ($line =~ /stop-reason=(.*?)$/)
		{
			$anvil->data->{switches}{'stop-reason'} = $1;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
				'switches::stop-reason' => $anvil->data->{switches}{'stop-reason'},
			}});
		}
		if ($line =~ /stop-servers=(.*?)$/)
		{
			$anvil->data->{switches}{'stop-servers'} = $1;
			$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
				'switches::stop-servers' => $anvil->data->{switches}{'stop-servers'},
			}});
		}
	}
}

# Make sure we're in an Anvil!
$anvil->data->{sys}{anvil_uuid} = $anvil->Cluster->get_anvil_uuid();
if (not $anvil->data->{sys}{anvil_uuid})
{
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 0, priority => "err", key => "error_0260"});
	$anvil->Job->update_progress({progress => 100, message => "error_0260"});
	$anvil->nice_exit({exit_code => 1});
}

# If no stop-reason was set, set it to 'user'
if (not $anvil->data->{switches}{'stop-reason'})
{
	$anvil->data->{switches}{'stop-reason'} = "user";
}

# Migrate or stop the servers, if any servers are running here.
process_servers($anvil);

# This waits on DRBD if we're SyncSource
wait_on_drbd($anvil);

# This stops pacemaker
stop_cluster($anvil);

# Are we powering off?
if ($anvil->data->{switches}{'power-off'})
{
	# Yup
	$anvil->Database->update_host_status({
		debug       => 2,
		host_uuid   => $anvil->Get->host_uuid,
		host_status => "stopping",
	});
	
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0325"});
	$anvil->Job->update_progress({progress => 100, message => "job_0325"});
	
	my $shell_call = $anvil->data->{path}{exe}{systemctl}." poweroff";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { shell_call => $shell_call }});
	my ($output, $return_code) = $anvil->System->call({shell_call => $shell_call, source => $THIS_FILE, line => __LINE__});
	
	# Unlikely we're still alive, but 'poweroff' does return once enqueued, so...
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
		output      => $output,
		return_code => $return_code,
	}});
}
else
{
	# We're not shutting down, so we're done
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0326"});
	$anvil->Job->update_progress({progress => 100, message => "job_0326"});
}

$anvil->nice_exit({exit_code => 0});


#############################################################################################################
# Functions                                                                                                 #
#############################################################################################################

# This takes down or migrates VMs, then withdraws from the cluster.
sub stop_cluster
{
	my ($anvil) = @_;
	
	# We need to rename the server in the cluster, and we need both nodes up to do it. 
	my $pacemaker_stopped = 0;
	my $waiting           = 1;
	while($waiting)
	{
		   $waiting = 0;
		my $problem = $anvil->Cluster->parse_cib({debug => 2});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { problem => $problem }});
		if ($problem)
		{
			# Cluster has stopped.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0313"});
			$anvil->Job->update_progress({progress => 5, message => "job_0313"});
		}
		else
		{
			$waiting = 1;
			if (not $pacemaker_stopped)
			{
				# Stop pacemaker now.
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0323"});
				$anvil->Job->update_progress({progress => 70, message => "job_0323"});
				
				### NOTE: '--force' is needed or else sole-running nodes can't exit 
				###       (complains about the loss of quorum)
				my $shell_call = $anvil->data->{path}{exe}{pcs}." cluster stop --force";
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { shell_call => $shell_call }});
				my ($output, $return_code) = $anvil->System->call({shell_call => $shell_call});
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
					output      => $output,
					return_code => $return_code,
				}});
				
				$pacemaker_stopped = 1;
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { pacemaker_stopped => $pacemaker_stopped }});
			}
			else
			{
				$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0324"});
				$anvil->Job->update_progress({progress => 80, message => "job_0324"});
			}
		}
		if ($waiting)
		{
			sleep 5;
		}
	}
	
	return(0);
}

# This will migrate or stop 
sub process_servers
{
	my ($anvil) = @_;
	
	if ($anvil->data->{switches}{'stop-servers'})
	{
		# Tell the user we're about to shut down servers.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0320"});
		$anvil->Job->update_progress({progress => 10, message => "job_0320"});
	}
	else
	{
		# Tell the user we're about to migrate servers.
		$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0321"});
		$anvil->Job->update_progress({progress => 10, message => "job_0321"});
	}
	my $waiting = 1;
	while ($waiting)
	{
		# Is the cluster up?
		   $waiting = 0;
		my $problem = $anvil->Cluster->parse_cib({debug => 2});
		$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { problem => $problem }});
		if ($problem)
		{
			# Nope.
			$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0313"});
			$anvil->Job->update_progress({progress => 80, message => "job_0313"});
		}
		else
		{
			# Loop through the servers running here.
			my $local_name = $anvil->data->{cib}{parsed}{'local'}{name};
			my $peer_name  = $anvil->data->{cib}{parsed}{peer}{name};
			foreach my $server (sort {$a cmp $b} keys %{$anvil->data->{cib}{parsed}{data}{server}})
			{
				my $status    = $anvil->data->{cib}{parsed}{data}{server}{$server}{status};
				my $host_name = $anvil->data->{cib}{parsed}{data}{server}{$server}{host_name};
				my $role      = $anvil->data->{cib}{parsed}{data}{server}{$server}{role};
				my $active    = $anvil->data->{cib}{parsed}{data}{server}{$server}{active};
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
					's1:server'    => $server,
					's2:status'    => $status,
					's2:host_name' => $host_name,
					's4:role'      => $role,
					's5:active'    => $active, 
				}});
				next if lc($role) eq "stopped";
				
				if (lc($role) eq "migrating")
				{
					# No matter what, if a server is migrating, we wait.
					$waiting = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { waiting => $waiting }});
					
					$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0315", variables => { server => $server }});
					$anvil->Job->update_progress({progress => 20, message => "job_0315,!!server!".$server."!!"});
				}
				elsif ($host_name eq $local_name)
				{
					# Something is running here.
					$waiting = 1;
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { waiting => $waiting }});
					
					# This is ours. How shall we deal with it?
					if ($anvil->data->{switches}{'stop-servers'})
					{
						# Have we tried to stop it already? If not, use pcs. If so, 
						# and if it's been more that 60 seconds, use virsh to try 
						# again.
						if (not exists $anvil->data->{server_shutdown}{$server})
						{
							# Use PCS.
							$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0316", variables => { server => $server }});
							$anvil->Job->update_progress({progress => 20, message => "job_0316,!!server!".$server."!!"});
							$anvil->Cluster->shutdown_server({
								debug  => 2,
								server => $server,
								'wait' => 0,
							});
							$anvil->data->{server_shutdown}{$server}{pcs_called}    = 1;
							$anvil->data->{server_shutdown}{$server}{virsh_called}  = 0;
							$anvil->data->{server_shutdown}{$server}{call_virsh_at} = time + 120;
							$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
								"server_shutdown::${server}::pcs_called"    => $anvil->data->{server_shutdown}{$server}{pcs_called}, 
								"server_shutdown::${server}::virsh_called"  => $anvil->data->{server_shutdown}{$server}{virsh_called}, 
								"server_shutdown::${server}::call_virsh_at" => $anvil->data->{server_shutdown}{$server}{call_virsh_at}, 
							}});
						}
						elsif ((not $anvil->data->{server_shutdown}{$server}{virsh_called}) && (time > $anvil->data->{server_shutdown}{$server}{call_virsh_at}))
						{
							# Use virsh
							$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0317", variables => { server => $server }});
							$anvil->Job->update_progress({progress => 20, message => "job_0317,!!server!".$server."!!"});
							$anvil->Server->shutdown_virsh({
								debug     => 2,
								server    => $server,
								wait_time => 1,
							});
							$anvil->data->{server_shutdown}{$server}{virsh_called} = 1;
							$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
								"server_shutdown::${server}::virsh_called" => $anvil->data->{server_shutdown}{$server}{virsh_called}, 
							}});
						}
					}
					else
					{
						### TODO: Calculate how many gigs worth of RAM we'll migrate,
						###       and advance the "progress" by the percentage each 
						###       server's RAM represents of the total
						# Migrate the servers.
						$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0318", variables => { 
							server => $server,
							node   => $peer_name,
						}});
						$anvil->Job->update_progress({progress => 20, message => "job_0318,!!server!".$server."!!,!!node!".$peer_name."!!"});
						$anvil->Cluster->migrate_server({
							server => $server,
							node   => $peer_name, 
							'wait' => 1,
						});
					}
				}
			}
		}
		if ($waiting)
		{
			sleep 5;
		}
	}
	
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0319"});
	$anvil->Job->update_progress({progress => 30, message => "job_0319"});
	
	return(0);
}

# This watches DRBD and waits for us to not be SyncSource.
sub wait_on_drbd
{
	my ($anvil) = @_;
	
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0322"});
	$anvil->Job->update_progress({progress => 40, message => "job_0322"});
	my $short_host_name = $anvil->Get->short_host_name();
	my $waiting         = 1;
	while ($waiting)
	{
		# (Re)fresh my view of the storage.
		$waiting = 0;
		$anvil->DRBD->get_status({debug => 2});
		
		# Now check to see if anything is sync'ing.
		foreach my $server_name (sort {$a cmp $b} keys %{$anvil->data->{drbd}{status}{$short_host_name}{resource}})
		{
			foreach my $peer_name (sort {$a cmp $b} keys %{$anvil->data->{drbd}{status}{$short_host_name}{resource}{$server_name}{connection}})
			{
				$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { peer_name => $peer_name }});
				foreach my $volume (sort {$a cmp $b} %{$anvil->data->{drbd}{status}{$short_host_name}{resource}{$server_name}{connection}{$peer_name}{volume}})
				{
					next if not exists $anvil->data->{drbd}{status}{$short_host_name}{resource}{$server_name}{connection}{$peer_name}{volume}{$volume}{'replication-state'};
					my $replication_state = $anvil->data->{drbd}{status}{$short_host_name}{resource}{$server_name}{connection}{$peer_name}{volume}{$volume}{'replication-state'};
					$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
						volume            => $volume,
						replication_state => $replication_state, 
					}});
					
					if ($replication_state =~ /SyncSource/i)
					{
						$waiting = 1;
						$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { waiting => $waiting }});
						
						$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0312", variables => { 
							peer_host => $peer_name,
							resource  => $server_name,
							volume    => $volume,
						}});
						$anvil->Job->update_progress({progress => 50, message => "job_0312,!!peer_host!".$peer_name."!!,!!resource!".$server_name."!!,!!volume!".$volume."!!"});
					}
				}
			}
		}
		if ($waiting)
		{
			sleep 10;
		}
	}
	
	# All servers should be down now, so stop DRBD.
	$anvil->Log->entry({source => $THIS_FILE, line => __LINE__, 'print' => 1, level => 1, key => "job_0314"});
	$anvil->Job->update_progress({progress => 60, message => "job_0314"});
	
	my $shell_call = $anvil->data->{path}{exe}{drbdadm}." down all";
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { shell_call => $shell_call }});
	my ($output, $return_code) = $anvil->System->call({shell_call => $shell_call});
	$anvil->Log->variables({source => $THIS_FILE, line => __LINE__, level => 2, list => { 
		output      => $output,
		return_code => $return_code,
	}});
	
	return(0);
}