my platform.app.yaml file

# This file describes an application. You can have multiple applications
# in the same project.
#
# The name of this app. Must be unique within a project.
name: myphpproject

# The type of the application to build.
type: php:5.6
build:
  flavor: symfony

# The relationships of the application with services or other applications.
# The left-hand side is the name of the relationship as it will be exposed
# to the application in the PLATFORM_RELATIONSHIPS variable. The right-hand
# side is in the form `<service name>:<endpoint name>`.
relationships:
    database: "mysql:mysql"

# The configuration of app when it is exposed to the web.
web:
    # The public directory of the app, relative to its root.
    document_root: "/web"
    # The front-controller script to send non-static requests to.
    passthru: "/app.php"

# The size of the persistent disk of the application (in MB).
disk: 2048

# The mounts that will be performed when the package is deployed.
mounts:
    "/app/cache": "shared:files/cache"
    "/app/logs": "shared:files/logs"

# The hooks that will be performed when the package is deployed.
hooks:
    build: |
      rm web/app_dev.php
    deploy: |
      app/console --env=prod cache:clear