Google App Engine - specify custom build dependenc

Question

My app needs cmake, libx11-dev and libpng-dev to build. I came across this documentation, which leads me to believe that I can list these as dependencies for my app to run on the Google App Engine platform, although I cannot figure out how. I was successfully able to run my app in a Compute Engine instance, although this is costly and, if I'm not mistaken, unnecessary. How do I get the packages listed at the beginning of the question installed beyond session end?

Answer 1

You need to keep in mind that the App Engine Flexible Environment still uses Compute Engine instances so may not get an additional benefit from moving across to this

Based on Google Compute Engine, the App Engine flexible environment automatically scales your app up and down while balancing the load.

The issue that you have is that if you require cmake, libx11-dev and libpng-dev to build your application you'll still need to use an underlying Compute Engine VM in order to run the application. This will be the case even if you consider moving across to Kubernetes Engine as well.

If you're looking to manage costs for your application, perhaps consider downsizing the VM to a smaller instance or look into modifying your application to suit the App Engine Standard Environment or use Cloud Functions

Answer 2

You can only list Node.js dependencies that way. From Declaring and managing dependencies (emphasis mine):

You can use any Linux-compatible Node.js package with App Engine flexible environment, including packages that require native (C) extensions.

You can use dependencies other than Node.js (at least cmake in your list) but only in the flexible environment, via a custom runtime. From About Custom Runtimes:

Custom runtimes allow you to define new runtime environments, which might include additional components like language interpreters or application servers.

See also Building Custom Runtimes.