sub does_image_exist()

in managementnode/lib/VCL/Module/Provisioning/xCAT.pm [649:785]

• 106 lines of code
• 21 McCabe index (conditional complexity)

sub does_image_exist {
	my $self = shift;
	unless (ref($self) && $self->isa('VCL::Module')) {
		notify($ERRORS{'CRITICAL'}, 0, "subroutine can only be called as a VCL::Module module object method");
		return;	
	}

	# Get the image name, first try passed argument, then data
	my $image_name = shift || $self->data->get_image_name();
	if (!$image_name) {
		notify($ERRORS{'WARNING'}, 0, "unable to determine image name");
		return;
	}
	
	# Get the image install type
	my $image_os_install_type = $self->data->get_image_os_install_type();
	if (!$image_os_install_type) {
		notify($ERRORS{'WARNING'}, 0, "image OS install type could not be determined");
		return;
	}
	else {
		notify($ERRORS{'DEBUG'}, 0, "image OS install type: $image_os_install_type");
	}

	# Get the image repository path
	my $image_repository_path = $self->get_image_repository_directory_path($image_name);
	if (!$image_repository_path) {
		notify($ERRORS{'WARNING'}, 0, "image repository path could not be determined");
		return;
	}
	else {
		notify($ERRORS{'DEBUG'}, 0, "image repository path: $image_repository_path");
	}
	
	# Run du to get the size of the image files if the image exists
	my $du_command;
	if ($image_os_install_type eq 'kickstart') {
		$du_command = "du -c $image_repository_path 2>&1 | grep total 2>&1"
	}
	else {
		$du_command = "du -c $image_repository_path/*$image_name* 2>&1 | grep total 2>&1"
	}

	my ($du_exit_status, $du_output) = $self->mn_os->execute($du_command);
	
	# If the partner doesn't have the image, a "no such file" error should be displayed
	my $image_files_exist;
	if (!defined($du_output)) {
		notify($ERRORS{'WARNING'}, 0, "failed to execute command $du_command");
		return;
	}
	elsif (grep(/no such file/i, @$du_output)) {
		notify($ERRORS{'OK'}, 0, "$image_name does NOT exist");
		$image_files_exist = 0;
	}
	elsif (!grep(/\d+\s+total/i, @$du_output)) {
		notify($ERRORS{'WARNING'}, 0, "du output does not contain a total line:\n" . join("\n", @$du_output));
		return;
	}
	
	# Return 1 if the image size > 0
	my ($image_size) = (@$du_output[0] =~ /(\d+)\s+total/);
	if ($image_size && $image_size > 0) {
		my $image_size_mb = int($image_size / 1024);
		notify($ERRORS{'DEBUG'}, 0, "$image_name exists in $image_repository_path, size: $image_size_mb MB");
		$image_files_exist = 1;
	}
	else {
		notify($ERRORS{'DEBUG'}, 0, "image does NOT exist: $image_name");
		$image_files_exist = 0;
	}

	# Image files exist, make sure template (.tmpl) file exists
	# Get the tmpl repository path
	my $tmpl_repository_path = $self->_get_tmpl_directory_path($image_name);
	if (!$tmpl_repository_path) {
		notify($ERRORS{'WARNING'}, 0, "image template path could not be determined for $image_name");
		return;
	}
	else {
		notify($ERRORS{'DEBUG'}, 0, "template repository path for $image_name: $tmpl_repository_path");
	}
	
	# Check if template file exists for the image
	# -s File has nonzero size
	my $tmpl_file_exists;
	if (-s "$tmpl_repository_path/$image_name.tmpl") {
		$tmpl_file_exists = 1;
		notify($ERRORS{'DEBUG'}, 0, "template file exists: $image_name.tmpl");
	}
	else {
		$tmpl_file_exists = 0;
		notify($ERRORS{'DEBUG'}, 0, "template file does not exist: $tmpl_repository_path/$image_name.tmpl");
	}
	
	# Check if either tmpl file or image files exist, but not both
	# Attempt to correct the situation:
	#    tmpl file exists but not image files: delete tmpl file
	#    image files exist but not tmpl file: create tmpl file
	if ($tmpl_file_exists && !$image_files_exist && $image_os_install_type ne 'kickstart') {
		notify($ERRORS{'WARNING'}, 0, "template file exists but image files do not for $image_name");

		# Attempt to delete the orphaned tmpl file for the image
		if ($self->_delete_template($image_name)) {
			notify($ERRORS{'OK'}, 0, "deleted orphaned template file for image $image_name");
			$tmpl_file_exists = 0;
		}
		else {
			notify($ERRORS{'WARNING'}, 0, "failed to delete orphaned template file for image $image_name, returning undefined");
			return;
		}
	} ## end if ($tmpl_file_exists && !$image_files_exist)
	elsif (!$tmpl_file_exists && $image_files_exist && $image_os_install_type ne 'kickstart') {
		notify($ERRORS{'WARNING'}, 0, "image files exist but template file does not for $image_name");

		# Attempt to create the missing tmpl file for the image
		if ($self->_create_template($image_name)) {
			notify($ERRORS{'OK'}, 0, "created missing template file for image $image_name");
			$tmpl_file_exists = 1;
		}
		else {
			notify($ERRORS{'WARNING'}, 0, "failed to create missing template file for image $image_name, returning undefined");
			return;
		}
	} ## end elsif (!$tmpl_file_exists && $image_files_exist) [ if ($tmpl_file_exists && !$image_files_exist)

	# Check if both image files and tmpl file were found and return
	if ($tmpl_file_exists && $image_files_exist) {
		notify($ERRORS{'DEBUG'}, 0, "image $image_name exists on this management node");
		return 1;
	}
	else {
		notify($ERRORS{'DEBUG'}, 0, "image $image_name does NOT exist on this management node");
		return 0;
	}

} ## end sub does_image_exist