webgui/lib/Spectre/Workflow.pm
2012-11-16 09:34:21 -08:00

571 lines
16 KiB
Perl

package Spectre::Workflow;
=head1 LEGAL
-------------------------------------------------------------------
WebGUI is Copyright 2001-2009 Plain Black Corporation.
-------------------------------------------------------------------
Please read the legal notices (docs/legal.txt) and the license
(docs/license.txt) that came with this distribution before using
this software.
-------------------------------------------------------------------
http://www.plainblack.com info@plainblack.com
-------------------------------------------------------------------
=cut
use strict;
use HTTP::Request::Common;
use HTTP::Cookies;
use POE qw(Component::Client::HTTP);
use Tie::IxHash;
use JSON qw/ encode_json /;
use Storable qw(dclone);
#-------------------------------------------------------------------
=head2 _start ( )
Initializes the workflow manager.
=cut
sub _start {
my ( $kernel, $self, $publicEvents) = @_[ KERNEL, OBJECT, ARG0 ];
$self->debug("Starting workflow manager.");
my $serviceName = "workflow";
$kernel->alias_set($serviceName);
$kernel->call( IKC => publish => $serviceName, $publicEvents );
$kernel->yield("checkInstances");
}
#-------------------------------------------------------------------
=head2 _stop ( )
Gracefully shuts down the workflow manager.
=cut
sub _stop {
my ($kernel, $self) = @_[KERNEL, OBJECT];
$self->debug("Stopping workflow manager.");
undef $self;
}
#-------------------------------------------------------------------
=head2 addInstance ( params )
Adds a workflow instance to the workflow processing queue.
=head3 params
A hash reference containing important information about the workflow instance to add to the queue.
=head4 sitename
The host and domain of the site this instance belongs to.
=head4 instanceId
The unqiue id for this workflow instance.
=head4 priority
The priority (1,2, or 3) that this instance should be run at.
=cut
sub addInstance {
my ($self, $instance) = @_[OBJECT, ARG0];
if ($instance->{priority} < 1 || $instance->{instanceId} eq "" || $instance->{sitename} eq "") {
$self->error("Can't add workflow instance with missing data: ". $instance->{sitename}." - ".$instance->{instanceId});
}
else {
$instance->{workingPriority} = ($instance->{priority} -1) * 10;
$instance->{lastState} = 'never run';
$instance->{status} = 'waiting';
$self->debug("Adding workflow instance ".$instance->{instanceId}." from ".$instance->{sitename}." to queue at priority ".$instance->{workingPriority}.".");
$self->{_queue}{$instance->{instanceId}} = $instance;
}
}
#-------------------------------------------------------------------
=head2 checkInstances ( )
Checks to see if there are any open instance slots available, and if there are assigns a new instance to be run to fill it.
=cut
sub checkInstances {
my ($kernel, $self) = @_[KERNEL, OBJECT];
$self->debug("Checking to see if we can run anymore instances right now.");
if ($self->countRunningInstances < $self->config->get("maxWorkers")) {
my $instance = $self->getNextInstance;
if (defined $instance) {
$kernel->yield("runWorker",$instance);
}
}
$kernel->delay_set("checkInstances",$self->config->get("timeBetweenRunningWorkflows"));
}
#-------------------------------------------------------------------
=head2 config ( )
Returns a reference to the config object.
=cut
sub config {
my $self = shift;
return $self->{_config};
}
#-------------------------------------------------------------------
=head2 countRunningInstances ( )
Returns an integer representing the number of running instances.
=cut
sub countRunningInstances {
my $self = shift;
my $count = 0;
foreach my $instance ($self->getInstances) {
if ($instance->{status} eq 'running') {
$count++;
}
}
$self->debug("There are $count running instances.");
return $count;
}
#-------------------------------------------------------------------
=head2 debug ( output )
Prints out debug information if debug is enabled.
=head3 output
The debug message to be printed if debug is enabled.
=cut
sub debug {
my $self = shift;
my $output = shift;
if ($self->{_debug}) {
print "WORKFLOW: ".$output."\n";
}
$self->getLogger->debug("WORKFLOW: ".$output);
}
#-------------------------------------------------------------------
=head2 deleteInstance ( instanceId )
Removes a workflow instance from the processing queue.
=cut
sub deleteInstance {
my ($self, $instanceId,$kernel, $session ) = @_[OBJECT, ARG0, KERNEL, SESSION];
$self->debug("Deleting workflow instance $instanceId from queue.");
delete $self->{_queue}{$instanceId};
}
#-------------------------------------------------------------------
=head2 editWorkflowPriority ( href )
Updates the priority of a given workflow instance.
=head3 href
Contains information about the instance and the new priority.
=head4 instanceId
The id of the instance to update.
=head4 newPriority
The new priority value.
=cut
sub editWorkflowPriority {
my ($self, $request, $kernel, $session ) = @_[OBJECT, ARG0, KERNEL, SESSION];
my ($argsHref, $rsvp) = @$request;
my $instanceId = $argsHref->{instanceId};
my $newPriority = $argsHref->{newPriority};
$self->debug("Updating the priority of $instanceId to $newPriority.");
my $instance = $self->getInstance($instanceId);
if (defined $instance) {
$instance->{priority} = $newPriority;
$instance->{workingPriority} = ($instance->{priority} -1) * 10;
$self->updateInstance($instance);
# return success message
$kernel->call(IKC=>post=>$rsvp, encode_json({message => 'edit priority success'}));
}
else {
# return an error message
my $error = 'edit priority instance not found error';
$kernel->call(IKC=>post=>$rsvp, encode_json({message => $error}));
}
}
#-------------------------------------------------------------------
=head2 error ( output )
Prints out error information if debug is enabled.
=head3 output
The error message to be printed if debug is enabled.
=cut
sub error {
my ($self, $output) = @_;
if ($self->{_debug}) {
print "WORKFLOW: [Error] ".$output."\n";
}
$self->getLogger->error("WORKFLOW: ".$output);
}
#-------------------------------------------------------------------
=head2 getInstance ( instanceId )
Returns the properties of an instance.
=head3 instanceId
The id of the instance to retrieve.
=cut
sub getInstance {
my ($self, $instanceId) = @_;
return dclone($self->{_queue}{$instanceId});
}
#-------------------------------------------------------------------
=head2 getInstances ( )
Returns the array of instances from the queue.
=cut
sub getInstances {
my ($self) = @_;
my @instances = values %{$self->{_queue}};
return @{dclone(\@instances)};
}
#-------------------------------------------------------------------
=head2 getJsonStatus ( )
Returns JSON report about the workflow engine. Depricated, use getStatus() instead.
=cut
sub getJsonStatus {
my ($kernel, $request, $self) = @_[KERNEL,ARG0,OBJECT];
my ($sitename, $rsvp) = @$request;
my %queues = (
Waiting => [],
Suspended => [],
Running => [],
);
my %output;
if ($sitename) { #must have entry for each queue
%output = %queues;
INSTANCE: foreach my $instance ($self->getInstances) {
next INSTANCE unless $instance->{sitename} eq $sitename;
my $queue = ucfirst($instance->{status});
push @{$output{$queue}}, [$instance->{workingPriority}, $instance->{instanceId}, $instance];
}
}
else {
foreach my $instance ($self->getInstances) {
my $site = $instance->{sitename};
unless (exists $output{$site}) { # must have an entry for each queue in each site
$output{$site} = dclone \%queues;
}
my $queue = ucfirst($instance->{status});
push @{$output{$site}{$queue}}, $instance;
}
}
$kernel->call(IKC=>post=>$rsvp, encode_json(\%output));
}
#-------------------------------------------------------------------
=head2 getStatus ( )
Returns JSON report about the workflow engine. Returns an array reference of hash references of instance data. Each instance contains the following fields: instanceId, status, lastState, sitename, priority, and workingPriority.
=cut
sub getStatus {
my ($kernel, $request, $self) = @_[KERNEL,ARG0,OBJECT];
my ($data, $rsvp) = @$request;
my @instances = $self->getInstances;
$kernel->call(IKC=>post=>$rsvp, encode_json(\@instances));
}
#-------------------------------------------------------------------
=head2 getLogger ( )
Returns a reference to the logger.
=cut
sub getLogger {
my $self = shift;
return $self->{_logger};
}
#-------------------------------------------------------------------
=head2 getNextInstance ( )
Returns the next available instance.
=cut
sub getNextInstance {
my $self = shift;
$self->debug("Looking for a workflow instance to run.");
my @instances = $self->getInstances;
if (scalar(@instances) > 0) {
my $lowInstance = {};
my $lowPriority = 999999999999;
my $waitingCount = 0;
foreach my $instance (@instances) {
next unless $instance->{status} eq 'waiting';
$waitingCount++;
if ($instance->{workingPriority} < $lowPriority) {
$lowInstance = $instance;
$lowPriority = $instance->{workingPriority};
}
}
$self->debug("Total workflows waiting to run: ".$waitingCount);
if ($lowInstance->{instanceId} ne '') {
$self->debug("Looks like ".$lowInstance->{instanceId}." would be a good workflow instance to run.");
return $lowInstance;
}
}
$self->debug("Didn't see any workflow instances to run.");
return undef;
}
#-------------------------------------------------------------------
=head2 new ( config, logger, [ , debug ] )
Constructor. Loads all active workflows from each WebGUI site and begins executing them.
=head3 config
The config object for spectre.
=head3 logger
A reference to the logger object.
=head3 debug
A boolean indicating Spectre should spew forth debug as it runs.
=cut
sub new {
my $class = shift;
my $config = shift;
my $logger = shift;
my $debug = shift;
my $self = {_debug=>$debug, _config=>$config, _logger=>$logger};
bless $self, $class;
my @publicEvents = qw(addInstance deleteInstance editWorkflowPriority getStatus getJsonStatus);
POE::Session->create(
object_states => [ $self => [qw(_start _stop returnInstanceToRunnableState addInstance checkInstances deleteInstance suspendInstance runWorker workerResponse), @publicEvents] ],
args=>[\@publicEvents]
);
my $cookies = HTTP::Cookies->new(file => '/tmp/cookies');
POE::Component::Client::HTTP->spawn(
Agent => 'Spectre',
Alias => 'workflow-ua',
CookieJar => $cookies
);
$self->{_queue} = {};
}
#-------------------------------------------------------------------
=head2 returnInstanceToRunnableState ( )
Returns a workflow instance back to runnable queue.
=cut
sub returnInstanceToRunnableState {
my ($self, $instance) = @_[OBJECT, ARG0];
$self->debug("Returning ".$instance->{instanceId}." to runnable state.");
$instance->{status} = 'waiting';
$self->updateInstance($instance);
}
#-------------------------------------------------------------------
=head2 runWorker ( )
Calls a worker to execute a workflow activity.
=cut
sub runWorker {
my ($kernel, $self, $instance, $session) = @_[KERNEL, OBJECT, ARG0, SESSION];
$self->debug("Preparing to run workflow instance ".$instance->{instanceId}.".");
$self->debug("Incrementing ".$instance->{instanceId}." priority from ".$instance->{workingPriority});
$instance->{workingPriority}++;
$instance->{status} = 'running';
$self->updateInstance($instance);
my $url = "http://".$instance->{sitename}.':'.$self->config->get("webguiPort").$instance->{gateway};
my $request = POST $url, [op=>"runWorkflow", instanceId=>$instance->{instanceId}];
my $cookie = $self->{_cookies}{$instance->{sitename}};
$request->header("Cookie",$instance->{cookieName}."=".$cookie) if (defined $cookie);
$request->header("X-instanceId",$instance->{instanceId});
$request->header("User-Agent","Spectre");
$self->debug("Posting workflow instance ".$instance->{instanceId}." to $url.");
$kernel->post('workflow-ua','request', 'workerResponse', $request);
$self->debug("Workflow instance ".$instance->{instanceId}." posted.");
}
#-------------------------------------------------------------------
=head2 suspendInstance ( )
Suspends a workflow instance for a number of seconds defined in the config file, and then returns it to the runnable queue.
=cut
sub suspendInstance {
my ($self, $kernel, $instance, $waitTimeout) = @_[OBJECT, KERNEL, ARG0, ARG1];
$waitTimeout ||= $self->config->get("suspensionDelay");
$self->debug("Suspending workflow instance ".$instance->{instanceId}." for ".$waitTimeout." seconds.");
$instance->{status} = 'suspended';
$self->updateInstance($instance);
$kernel->delay_set("returnInstanceToRunnableState", $waitTimeout, $instance);
}
#-------------------------------------------------------------------
=head2 updateInstance ( properties )
Updates an instance's properties.
=head3 properties
A hash reference of the properties of the instance.
=cut
sub updateInstance {
my ($self, $instance) = @_;
$self->debug("Updating ".$instance->{instanceId}."'s properties.");
$self->{_queue}{$instance->{instanceId}} = $instance;
}
#-------------------------------------------------------------------
=head2 workerResponse ( )
This method is called when the response from the runWorker() method is received.
=cut
sub workerResponse {
my ($self, $kernel, $requestPacket, $responsePacket) = @_[OBJECT, KERNEL, ARG0, ARG1];
$self->debug("Retrieving response from workflow instance.");
my $request = $requestPacket->[0];
my $response = $responsePacket->[0];
my $instanceId = $request->header("X-instanceId"); # got to figure out how to get this from the request, cuz the response may die
$self->debug("Response retrieved is for $instanceId.");
my $instance = $self->getInstance($instanceId);
unless (defined $instance) {
$self->debug("Instance $instanceId no longer exist in my queue, so there's no reason to process the response.");
return;
}
if ($response->is_success) {
$self->debug("Response for $instanceId retrieved successfully.");
if ($response->header("Set-Cookie") ne "") {
$self->debug("Storing cookie for $instanceId for later use.");
my $cookie = $response->header("Set-Cookie");
my $pattern = $instance->{cookieName}."=([a-zA-Z0-9\_\-]{22}).*";
$cookie =~ s/$pattern/$1/;
$self->{_cookies}{$instance->{sitename}} = $cookie;
}
my $state = $response->content;
$instance->{lastState} = $state;
$instance->{lastRunTime} = localtime(time());
if ($state =~ m/^waiting\s*(\d+)?$/) {
my $waitTime = $1;
$self->debug("Was told to suspend $instanceId because we're still waiting on some external event.");
$kernel->yield("suspendInstance",$instance, $waitTime);
}
elsif ($state eq "complete") {
$self->debug("Workflow instance $instanceId ran one of it's activities successfully.");
$kernel->yield("returnInstanceToRunnableState",$instance);
}
elsif ($state eq "disabled") {
$self->debug("Workflow instance $instanceId is disabled.");
$kernel->yield("suspendInstance",$instance);
}
elsif ($state eq "done") {
$self->debug("Workflow instance $instanceId is now complete.");
$kernel->yield("deleteInstance",$instanceId);
}
elsif ($state eq "error") {
$self->debug("Got an error response for $instanceId.");
$kernel->yield("suspendInstance",$instance);
}
else {
$self->error("Something bad happened on the return of $instance->{sitename} - $instanceId. ".$response->code.": ".$response->message);
$kernel->yield("suspendInstance",$instance);
}
}
elsif ($response->is_redirect) {
$self->error("Response for $instance->{sitename} - $instanceId was redirected. This should never happen if configured properly!!!");
$instance->{lastState} = "redirect";
$instance->{lastRunTime} = localtime(time());
$kernel->yield("suspendInstance",$instance)
}
elsif ($response->is_error) {
$instance->{lastState} = "comm error";
$instance->{lastRunTime} = localtime(time());
$self->error("Response for $instance->{sitename} - $instanceId had a communications error. ".$response->code.": ".$response->message);
$kernel->yield("suspendInstance",$instance)
}
}
1;