[install] Work on install mechanism so modules can independently install/update tables

1 files changed, 240 insertions, 0 deletions

diff --git a/install.php b/install.php
new file mode 100644
index 00000000..e579dd52
--- /dev/null
+++ b/install.php
@@ -0,0 +1,240 @@
+<?php
+
+/*
+ * Modular installation system.
+ *
+ * Since most of slx-admin is now modularized, it might not make too much sense to have
+ * static central SQL dumps of the database scheme. Tables usually belong to specific modules,
+ * so they should only be created if the module is actually in use.
+ * Thus, we have a modular install system where modules should create (and update) database
+ * tables that belong to them.
+ * The system should not be abused to modify tables of other modules by adding or changing
+ * columns, which could lead to a maintenance nightmare over time.
+ *
+ * The install/update mechanism could also be used to setup other requirements, like directories,
+ * permissions etc. Each module's install hook should report back the status of the module's
+ * requirements. For examples see some modules like baseconfig, main, statistics, ...
+ *
+ * Warning: Be careful which classes/functionality of slx-admin you use in your scripts, since
+ * they might depend on some tables that do not exist yet. ;)
+ */
+
+/**
+ * Report back the update status to the browser/client and terminate execution.
+ * This has to be called by an update module at some point to signal the result
+ * of its execution.
+ *
+ * @param $status one of the UPDATE_* status codes
+ * @param string $message Human readable description of the status (optional)
+ */
+function finalResponse($status, $message = '')
+{
+	if (!DIRECT_MODE && AJAX) {
+		echo json_encode(array('status' => $status, 'message' => $message));
+	} else {
+		echo 'STATUS=', $status, "\n";
+		echo 'MESSAGE=', $message;
+	}
+	exit;
+}
+
+define('UPDATE_DONE', 'UPDATE_DONE'); // Process completed successfully. This is a success return code.
+define('UPDATE_NOOP', 'UPDATE_NOOP'); // Nothing had to be done, everything is up to date. This is also a success code.
+define('UPDATE_RETRY', 'UPDATE_RETRY'); // Install/update process failed, but should be retried later.
+define('UPDATE_FAILED', 'UPDATE_FAILED'); // Fatal error occured, retry will not resolve the issue.
+
+/*
+ * Helper functions for dealing with the database
+ */
+
+function tableHasColumn($table, $column)
+{
+	$table = preg_replace('/\W/', '', $table);
+	$column = preg_replace('/\W/', '', $column);
+	$res = Database::simpleQuery("DESCRIBE `$table`", array(), true);
+	if ($res !== false) {
+		while ($row = $res->fetch(PDO::FETCH_ASSOC)) {
+			if ((is_array($column) && in_array($row['Field'], $column)) || (is_string($column) && $row['Field'] === $column))
+				return true;
+		}
+	}
+	return false;
+}
+
+function tableDropColumn($table, $column)
+{
+	$table = preg_replace('/\W/', '', $table);
+	$column = preg_replace('/\W/', '', $column);
+	$res = Database::simpleQuery("DESCRIBE `$table`", array(), true);
+	if ($res !== false) {
+		while ($row = $res->fetch(PDO::FETCH_ASSOC)) {
+			if ((is_array($column) && in_array($row['Field'], $column)) || (is_string($column) && $row['Field'] === $column))
+				Database::exec("ALTER TABLE `$table` DROP `{$row['Field']}`");
+		}
+	}
+}
+
+function tableExists($table)
+{
+	$res = Database::simpleQuery("SHOW TABLES", array(), true);
+	while ($row = $res->fetch(PDO::FETCH_ASSOC)) {
+		if ($row['Tables_in_openslx'] === $table)
+			return true;
+	}
+	return false;
+}
+
+/*
+ * Rest of install script....
+ */
+
+if (!isset($_SERVER['REMOTE_ADDR']) || isset($_REQUEST['direct'])) {
+	define('DIRECT_MODE', true);
+} else {
+	define('DIRECT_MODE', false);
+}
+
+define('AJAX', ((isset($_REQUEST['async'])) || (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) === 'xmlhttprequest')));
+
+error_reporting(E_ALL);
+chdir(dirname($_SERVER['SCRIPT_FILENAME']));
+
+// Autoload classes from ./inc which adhere to naming scheme <lowercasename>.inc.php
+spl_autoload_register(function ($class) {
+	$file = 'inc/' . preg_replace('/[^a-z0-9]/', '', mb_strtolower($class)) . '.inc.php';
+	if (!file_exists($file))
+		return;
+	require_once $file;
+});
+
+if (!is_readable('config.php')) {
+	finalResponse(UPDATE_FAILED, 'config.php does not exist!');
+}
+
+require_once 'config.php';
+
+if (CONFIG_SQL_PASS === '%MYSQL_OPENSLX_PASS%') {
+	finalResponse(UPDATE_FAILED, 'mysql credentials not configured yet!');
+}
+
+// Explicitly connect to the database so it won't call Util::traceError() on failure
+if (!Database::init(true)) {
+	finalResponse(UPDATE_RETRY, 'Connecting to the database failed');
+}
+
+// Good to go so far
+
+/**
+ * @param \Module $module
+ * @return bool
+ */
+function hasUpdateScript($module)
+{
+	return is_readable($module->getDir() . '/install.inc.php');
+}
+
+function runUpdateScript($module)
+{
+	require_once $module->getDir() . '/install.inc.php';
+}
+
+// Build dependency tree
+Module::init();
+$modules = Module::getEnabled();
+if (empty($modules)) {
+	finalResponse(UPDATE_NOOP, 'No active modules, nothing to do');
+}
+
+if (DIRECT_MODE) {
+	//
+	// Direct mode - plain
+	$new = array();
+	foreach ($modules as $entry) {
+		if (hasUpdateScript($entry)) {
+			$new[] = $entry;
+		}
+	}
+	$modules = $new;
+	if (empty($modules)) {
+		finalResponse(UPDATE_NOOP, 'No modules with install scripts, nothing to do');
+	}
+	// Get array where the key maps a module identifier to the next module object
+	$assoc = array();
+	$count = count($modules);
+	for ($i = 0; $i < $count; ++$i) {
+		$assoc[$modules[$i]->getIdentifier()] = $modules[($i + 1) % $count];
+	}
+
+	if (!empty($argv[1])) {
+		$last = $argv[1];
+	} else {
+		$last = Request::any('last', '', 'string');
+	}
+	if (!empty($last) && isset($assoc[$last])) {
+		$module = $assoc[$last];
+	}
+	if (!isset($module)) {
+		$module = $modules[0];
+	}
+	echo 'MODULE=', $module->getIdentifier(), "\n";
+	runUpdateScript($module);
+} else {
+	//
+	// Interactive web based mode
+	$mod = Request::any('module', false, 'string');
+	if ($mod !== false) {
+		// Execute specific module
+		$module = Module::get($mod, true);
+		if ($module === false) {
+			finalResponse(UPDATE_NOOP, 'Given module does not exist!');
+		}
+		if (!hasUpdateScript($module)) {
+			finalResponse(UPDATE_NOOP, 'Given module has no install script');
+		}
+		runUpdateScript($module);
+		finalResponse(UPDATE_DONE, 'Module did not report status; assuming OK');
+	}
+	// Show the page that shows status and triggers jobs
+	echo <<<HERE
+<!DOCTYPE html>
+<html>
+	<head>
+		<title>Install/Update SLXadmin</title>
+		<meta charset="utf-8"> 
+		<meta http-equiv="X-UA-Compatible" content="IE=edge">
+		<style type="text/css">
+		body, html {
+			color: #000;
+			background: #fff;
+		}
+		table, tr, td {
+			border: 1px solid #ccc;
+			border-collapse: collapse;
+			padding: 3px;
+		}
+		button {
+			font-weight: bold;
+			padding: 8px;
+		}
+		</style>
+	</head>
+	<body>
+		<h1>Modules</h1>
+		<table>
+			<tr><th>Module</th><th>Status</th></tr>
+HERE;
+	foreach ($modules as $module) {
+		$id = $module->getIdentifier();
+		echo "<tr><td class=\"id-col\">{$id}</td><td id=\"mod-{$id}\">Waiting...</td></tr>";
+	}
+	echo <<<HERE
+		</table>
+		<br><br>
+		<button onclick="slxRunInstall()">Install/Upgrade</button>
+		<script src="script/jquery.js"></script>
+		<script src="script/install.js"></script>
+	</body>
+</html>
+HERE;
+
+}
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