Looking for a way to package a module inside a component package, I came across the following technique. Re-use the JInstaller class and the com_installer install from folder code as well as the unpack methods to unzip.

The technique at it’s root starts with the custom install script placed inside the install.[component_name].php that contains the “magic” function com_install() of your own design. Another trick that is used is to include the module within the admin section of the install. There are several includes that I have entered such as:
jimport( ‘joomla.installer.installer’ );
jimport(‘joomla.filesystem.file’);
jimport(‘joomla.filesystem.folder’);
jimport(‘joomla.filesystem.archive’);
jimport(‘joomla.filesystem.path’);
but the heart of the code is as follows:

function com_install(){
	global $mainframe;
	$tmp = JPATH_ROOT.DS."tmp" ;
	$archivename = $p_dir = dirname( __FILE__).DS."module.zip";
	// Temporary folder to extract the archive into
	$tmpdir = uniqid('install_');

	// Clean the paths to use for archive extraction
	$extractdir = JPath::clean(JPATH_ROOT.DS."tmp".DS.$tmpdir);
	$archivename = JPath::clean($archivename);

	// do the unpacking of the archive
	$result = JArchive::extract( $archivename, $extractdir);

	if ( $result === false ) {
		JError::raiseWarning('SOME_ERROR_CODE', JText::_('Failed to extract'));
		return "Failed Extract";
	}

	$p_dir = JPath::clean( $extractdir );
	// Did you give us a valid directory?
	if (!is_dir($p_dir)) {
		JError::raiseWarning('SOME_ERROR_CODE', JText::_('Please enter a package directory'));
		return "Not a valid Install Directory" ;
	}

	// Detect the package type
	$type = JInstallerHelper::detectType($p_dir);

	// Did you give us a valid package?
	if (!$type) {
		JError::raiseWarning('SOME_ERROR_CODE', JText::_('Path does not have a valid package'));
		return false;
	}

	$package['packagefile'] = null;
	$package['extractdir'] = null;
	$package['dir'] = $p_dir;
	$package['type'] = $type;

	if (!$package) {
		$this->setState('message', 'Unable to find install package');
		return "Not A Package";
	}

	// Get a database connector
	//$db = & JFactory::getDBO();

	// Get an installer instance
	$installer =& JInstaller::getInstance();

	// Install the package
	if (!$installer->install($package['dir'])) {
		// There was an error installing the package
		$msg = JText::sprintf('INSTALLEXT', JText::_($package['type']), JText::_('Error'));
		$result = false;
		return "Install Failed" ;
	} else {
		// Package installed sucessfully
		$msg = JText::sprintf('INSTALLEXT', JText::_($package['type']), JText::_('Success'));
		$result = true;
	}

	// Set some model state values
	$mainframe->enqueueMessage($msg);

	// Cleanup the install files
	if (!is_file($package['packagefile'])) {
		$config =& JFactory::getConfig();
		$package['packagefile'] = $config->getValue('config.tmp_path').DS.$package['packagefile'];
		return "fail" ;
	}

	JInstallerHelper::cleanupInstall($package['packagefile'], $package['extractdir']);
	return "Success" ;
}

If you take a look at the normal install there is some code familiarity with the install from url and install from folder.