title: Custom runtime for non-flexible environment app?
body: <p>I don't think that my gae python app has a flexible environment because I created it many years ago. Now I want to try and create a module that has another runtime than python and keep the python app running python alongside a new runtime, custom or just another. Maybe mix PHP and python or similar. I don't need it but I want to learn and explore the possibilities. I'm also interested in learning Erlang and deploy Erlang code with appengine. I see there is questions about it already</p>
  
  <p><a href="https://stackoverflow.com/questions/1654759/erlang-on-google-app-engine">erlang on google app engine?</a></p>
  
  <p>And <a href="https://code.google.com/p/googleappengine/issues/detail?id=125#makechanges" rel="nofollow noreferrer">issue 125 in the tracker</a>. </p>
  
  <p>But how should we actually do it? If we make our own runtime provided that is allowed. </p>
  
  <p>My app.yaml looks like </p>
  
  <pre><code>application: montaoproject
  version: newsearch
  runtime: python27
  api_version: 1
  threadsafe: true
  module: default
  instance_class: F1
  automatic_scaling:
    min_idle_instances: 5
    max_idle_instances: automatic
    min_pending_latency: automatic
    max_pending_latency: 30ms
    max_concurrent_requests: 50
  
  default_expiration: "14d 5h"
  
  env_variables:
    GAE_USE_MONTAO : 'anyvalue'
    KOOL_VERSION : '17a'
  
  includes:
  - br.yaml # Brazil
  - in.yaml # India
  - us.yaml # USA
  - pk.yaml
  - search.yaml # search pages
  - admin.yaml # admin pages
  - providers.yaml # auth providers
  - statics.yaml # static content
  
  handlers:
  - url: /(business|ai|newindia|insert-ad.html)
    script: montao.app
  
  - url: /blobview.*
    script: kool_update.app
    login: admin
  
  - url: /market.*
    script: main.app
  
  - url: /
    script: montao.app
  
  - url: /(index.html|sign-up.html|login.html)
    script: montao.app
  
  - url: /(login.*|login|googlogin|googlogout|create/)
    script: login.app
  
  - url: /(customer_service.htm|contactfileupload|support.html|faq.html)
    script: customer_service.app
  
  - url: /stats.*
    script: google.appengine.ext.appstats.ui.app
  
  # All other URLs use main.app
  - url: /.*
    script: main.app
  
  inbound_services:
  - mail
  
  builtins:
  - remote_api: on
  - deferred: on
  #- appstats: on
  
  error_handlers:
    - file: default_error.html
  
  libraries:
  - name: webapp2
    version: latest
  - name: jinja2
    version: latest
  - name: setuptools
    version: latest
  - name: markupsafe
    version: latest
  - name: django
    version: latest
  - name: PIL
    version: latest
  - name: webob
    version: latest
  - name: lxml
    version: latest
  - name: ssl
    version: latest
  </code></pre>