Customizing the PHP Runtime

You can use custom runtimes to add additional functionality to a PHP app running in the flexible environment. To configure a custom runtime, you replace this line in your app.yaml file:

runtime: php

with this line:

runtime: custom

You must also add a Dockerfile in the same directory that contains the app.yaml file. For building PHP containers, Google provides this base image:

Base Image Health Checks
gcr.io/google-appengine/php Yes

You can automatically generate the Dockerfile for your current runtime using gen-config:

gcloud beta app gen-config --custom

Health checking

By default, all programs running in the flexible environment receive health check requests. The base image gcr.io/google_appengine/php responds to the health check request, so you don't have to write your own health check handler. If you're using a different image, you need to disable health checks, or write your own code to handle health check requests.