Hey Ram,
I believe you're referring to the
yaml extension of PHP, found at PECL. The documentation for the App Engine PHP runtime shows
which extensions are enabled by default and which are dynamically-loadable. The yaml extension is not among these, so it's not available on App Engine as it is.
However you could search online for pure PHP yaml parsers which you could use.
I found one on github after a quick google, but don't consider this an "endorsement", you'll need to evaluate yourself whether it fits your needs, and this library is not in any way the responsibility of Google. It's a fork of
this other library (same qualifications apply).
I hope this has been helpful in thinking about what libraries are available as extensions, and which need to be included along with your app during upload as pure-PHP resources. Let me know if you have any further questions!
Regards,
Nick
Cloud Platform Community Support