Author Archives: slangley

Direct File Uploads for PHP 5.5

One of the new features we announced in the 1.9.18 App Engine release is the ability to upload files directly to you application, without the need to upload the files to Google Cloud Storage first.

Direct uploads leverages the same in memory virtual filesystem that is used to provide temporary filesystem support. Direct uploads are only available with the PHP 5.5 runtime and are also limited to a maximum combined size of 32MB, which is the incoming request size limit.

Direct Upload Example

Following is a small sample application that demonstrates direct file uploads. This sample application:

  • Uses HTML5 multiple file upload support to upload image files.
  • Saves the original uploaded file into Google Cloud Storage.
  • Creates a greyscale version of the uploaded image and writes that to Google Cloud Storage.
  • Uses the image serving API to create links to serve the stored images at original size.
  • Also uses the image serving API to create thumbnail links of the images, without the application having to create the thumbnails.
  • Finally, displays a simple page with the thunbnailed links to the saved files.

For this application we’ll create 3 source files.


The app.yaml file has the following contents. Note that the runtime is php55.

application: php-uploads
version: 1
runtime: php55
api_version: 1
threadsafe: true

- url: /handle_upload
  script: handle_upload.php

- url: .*
  script: direct_upload.php


This file presents a form for the user to upload multiple files to your application. As direct uploads are only in PHP 55 it checks that as well.

// Direct uploads requires PHP 5.5 on App Engine.
if (strncmp("5.5", phpversion(), strlen("5.5")) != 0) {
  die("Direct uploads require the PHP 5.5 runtime. Your runtime: " . phpversion());
<form action="handle_upload" method="post" enctype="multipart/form-data">
  Send these files:<p/>
  <input name="userfile[]" type="file" multiple="multiple"/><p/>
  <input type="submit" value="Send files" />


The handle_upload script does the heavy lifting of creating the greyscale images, saving them in Cloud Storage and displaying the results. If you were doing this in a production app you’d need a lot more error handling, but I’ve left it out for brevity.


use google\appengine\api\cloud_storage\CloudStorageTools;

$bucket = CloudStorageTools::getDefaultGoogleStorageBucketName();
$root_path = 'gs://' . $bucket . '/' . $_SERVER["REQUEST_ID_HASH"] . '/';

$public_urls = [];
foreach($_FILES['userfile']['name'] as $idx => $name) {
  if ($_FILES['userfile']['type'][$idx] === 'image/jpeg') {
    $im = imagecreatefromjpeg($_FILES['userfile']['tmp_name'][$idx]);
    imagefilter($im, IMG_FILTER_GRAYSCALE);
    $grayscale = $root_path .  'gray/' . $name;
    imagejpeg($im, $grayscale);

    $original = $root_path . 'original/' . $name;
    move_uploaded_file($_FILES['userfile']['tmp_name'][$idx], $original);

    $public_urls[] = [
        'name' => $name,
        'original' => CloudStorageTools::getImageServingUrl($original),
        'original_thumb' => CloudStorageTools::getImageServingUrl($original, ['size' => 75]),
        'grayscale' => CloudStorageTools::getImageServingUrl($grayscale),
        'grayscale_thumb' => CloudStorageTools::getImageServingUrl($grayscale, ['size' => 75]),

foreach($public_urls as $urls) {
  echo '<a href="' . $urls['original'] .'"><IMG src="' . $urls['original_thumb'] .'"></a> ';
  echo '<a href="' . $urls['grayscale'] .'"><IMG src="' . $urls['grayscale_thumb'] .'"></a>';
  echo '<p>';
<a href="/">Upload More</a>

If you stumble across any problems, please let us know on either stack overflow or by creating an issue in our tracker.

File system changes in App Engine 1.9.18

In the 1.9.18 App Engine release we added a two new filesystem features to help application developers. The first is a change to the local filesystem in the development server that makes it appear to be readonly, to match how the application works in production. The second is we’ve added an in memory virtual filesystem that makes it possible to create temporary files using sys_get_temp_dir and associated functions.

Development Server Read-Only File System

We notices that a lot of new developers were caught out by the fact that the local filesystem in production is read-only, so we added a feature to mimic this behavior in the development environment. Now, by default, if your application tries to write to the local filesystem you will see an error message similar to what is shown below.

>>> file_put_contents('foo.txt', 'ttt');
file_put_contents(foo.txt): failed to open stream: Read-only file system

We know there are scenarios where you want to be able to write to the local filesystem, for example if pre-caching data before you deploy the application to production. To make this possible, we’ve added a flag that you can set in your applications php.ini file to make the filesystem read/write. Note this flag only works in the development server, the local filesystem will always be readonly in production.

To make the filesystem read/write, add the following to your php.ini file.

google_app_engine.disable_readonly_filesystem = 1

Then you’ll be able to write to the local filesystem without restriction – just remember that the production filesystem is always read-only.

Memory backed virtual filesystem

In the new PHP 5.5 runtime You can now use sys_get_temp_dir(), tmpfile() and tempnam() functions to create temporary files.

The temporary files generated are stored in an in memory virtual filesystem. The paths will start with vfs:// and look something like

>>> echo tempnam('foo', 'bar');
>>> echo sys_get_temp_dir();

The in memory filesystem will be flushed at the end of the request, and is not shared in between requests to the same instance. We’ve made it possible to call rename() with a cloud storage path as the destination so that you can write out the temporary file for permanent storage.

$tmp_name = tempnam('foo', 'bar');
$gcs_file = 'gs://my_bucket/foo/bar.txt';

file_put_contents($tmp_name, "Hello World");
rename($tmp_name, $gcs_file);
echo file_get_contents($gcs_file);

If you run into any problems with either of these new features, please let us know by filing an issue.

AppEngine WordPress plugin version 1.6 released

We’re happy to announce the latest release of the AppEngine WordPress plugin, version 1.6. We encourage all users of WordPress on App Engine to upgrade to this new version as soon as possible.

This new versions includes the following bug fixes.

  • Media uploads will no longer generate an HTTP error if editing the page for more than 10 minutes.
  • Fix error with image sizes not being shown correctly when attaching images to a post.

Please report any issues with the plugin in the support forum, or ask questions on stackoverflow where members of the team actively participate.

We also gladly accept pull requests – you can find the plugin source on Github.

Update your Google API PHP Client

tl;dr – The canary process for the 1.9.17 PHP Runtime has identified an issue with the Google APIs Client Library for PHP that will cause applications to break. Update your version to at least 1.1.2 ASAP.

Hi All,

During the canary process for the new version of the PHP runtime, an issue has been uncovered related to the Google API PHP client and the cURL extension. The App Engine sockets library does not allow socket connections to, which prevents the client library from working if it uses cURL, which is it’s default configuration.

We have made a change to the client library so that it will always use PHP streams on App Engine, which prevents this error from occurring. However this means that your application code will need to be updated to the new version of the client library and the code re-deployed to the production environment.

To reduce the possibility of an outage for your application we encourage you to update this library and re-deploy your application as soon as possible.

In the meantime we continue to assess the number of affected applications to determine what the best course of action is to ensure minimal disruption for existing apps. This may well mean delaying the release of the PHP 5.5 runtime with cURL support to allow sufficient time for applications to be upgraded.

Update 28 Nov: We have decided to roll back the 1.9.17 PHP release with PHP 5.5 and cURL for the time being. You have plenty of time to update your applications to the latest API client.


App Engine PHP 1.9.17 pre-release SDK

Well it’s been a while since the PHP team have had any updates to post to this blog. For the last few months the team has been heads down working with the rest of the App Engine team working on improving the reliability, stability and performance of the platform. You can read a little more on this in this post that our very own VP Daniel Sturman made on the App Engine discussion forum.

That being said, we’re ready to get the ball rolling once more on delivering a great PHP experience on App Engine, moving the platform from experimental to GA as soon as possible. In fact, we have the following features ready to launch in the next App Engine release, 1.9.17.

  • Upgrading the interpreter to PHP 5.5.18, which includes
    • support for Zend opcache.
    • APCu extension for in process caching.
    • backend improvements for parallel request serving from the same runtime instance.
  • Adding support for the cURL extension.
  • Adding support for the mailparse extension.

Now usually we do not pre-announce features that are scheduled in an upcoming release, because plans can change at the last minute and features can be pushed back a release or two (which could still happen here). But we regard this is a special case as the change from PHP 5.4.32 to PHP 5.5.18 could break existing applications. There is a small list of PHP 5.5 backwards incompatible changes and we want to give you developers a chance to fix any issues that your apps might have because of the switch.

To assist in identifying any potential problems in your applications, we’ve created 1.9.17 pre-release SDKs that have the PHP 5.5 interpreter bundled. You can download these SDKs from the following links.

For linux users, we suggest building the interpreter from source, using the following shell commands.

  sudo apt-get install gcc libmysqlclient-dev libxml2-dev libcurl4-openssl-dev libpng-dev libjpeg-dev
  wget --trust-server-names
  tar -xvf php-5.5.18.tar.bz2
  cd php-5.5.18
  ./configure --prefix=$DEST/installdir \
    --enable-bcmath \
    --enable-calendar \
    --enable-ftp \
    --enable-mbstring \
    --enable-opcache \
    --enable-soap \
    --enable-sockets \
    --enable-zip \
    --disable-fileinfo \
    --disable-flatfile \
    --disable-posix \
    --with-curl \
    --with-gd \
    --with-openssl \
    --without-sqlite3 \
    --without-pdo-sqlite \
    --without-imap \
    --without-kerberos \
    --without-interbase \
    --without-ldap \
    --without-mssql \
    --without-oci8 \
    --without-pgsql \
    --without-pear \
    --disable-phar \
    --without-snmp \
    --enable-mysqlnd \
    --with-pdo-mysql=mysqlnd \
    --with-mysqli=mysqlnd \
  make install -j
  cd -

This will build an php-cgi binary that is used by the App Engine development server, which can be found located in the folder $DEST/app_engine/5.5/installdir/bin. Follow these instructions to run the development appserver with the php-cgi binary that you’ve built.

As always, you can report any issues in the public issue tracker and we’ll do our best to solve them promptly.


AppEngine WordPress plugin version 1.4 released.

We’re happy to announce the latest release of the AppEngine WordPress plugin, version 1.4. We encourage all users of WordPress on App Engine to upgrade to this new version as soon as possible.

This new versions includes a number of bug fixes, as well as a new feature for serving media files over HTTPs.

Bug Fixes

This version of the plugin includes fixes for the following bugs:

  • The default HTTP fetch timeout is now 30 seconds, and fetch errors include a more descriptive message.
  • The public URLs for uploaded media now work correctly in the development environment.
  • The plugin now uses autoloading in the AppEngine SDK to improve load time performance.

New Features

This version of the plugin includes a new feature, that makes it possible to serve uploaded media files over HTTPs or HTTP.

To enable HTTPs serving of uploaded media, select the checkbox in the plugin settings page, as shown below.

Secure URLs checkbox.

Once selected, all media files that are subsequently uploaded will be served over https. Note: Changing this setting has no affect on media files that have already been uploaded.

Please report any issues with the plugin in the support forum, or ask questions on stackoverflow where members of the team actively participate.

We also gladly accept pull requests – you can find the plugin source on Github.


AppEngine WordPress plugin Version 1.3 Released

We’re happy to announce that we’ve just released version 1.3 of the AppEngine WordPress plugin. We encourage all users of WordPress on App Engine to upgrade to this new version as soon as possible.

The new version of the plugin includes the following features and bug fixes.

  • Import support for WordPress export files, forked from the popular WordPress importer plugin.
  • URLFetch support for WordPress versions 3.7 and above, that fixes issues caused by core WordPress changes to the WT_HTTP Class.
  • Bug fix for incorrectly detecting if a Google Cloud Storage bucket was writable by the application during setup.
  • Better logging of plugin errors.

Like always, please report any issues with the plugin in the support forum.

We also gladly accept pull requests – you can find the plugin source on Github.

App Engine WordPress plugin Version 1.2 released

We’re happy to announce that we’ve just released version 1.2 of the App Engine WordPress plugin. The new version includes the following changes

  • Fix for the bug “Uncaught exception ‘InvalidArgumentException’ with message ‘max_bytes_per_blob must be an integer'” (forum link)
  • Removes the need for PIL to be installed in the local development environment.
  • Removes the need for PyCrypto to be installed in the local development environment.
  • Better checking if the application has write access to the Google Cloud Storage bucket for uploads.

If you find any issues with the latest version of the plugin you can file them in the support forum.

We also gladly accept pull requests – you can find the plugin source on Github.

Generating Dynamic WordPress sitemaps on App Engine

Sitemaps are a valuable tool in helping search engines crawl your website. In this post I’ll show you how you can have a dynamically generated sitemap for a WordPress blog hosted on Google App Engine.

Because of the read-only nature of the file system on App Engine, we’ll use Google Cloud Storage to store the generated sitemap file. We’ll also add some handlers to serve the sitemap, and to update it as part of a scheduled cron job.

Continue reading