[WIP] memcache for GAE migration

.gitignore

@@ -3,3 +3,4 @@
 /config.json
 *.pyc
 .idea
+lib

README.md

@@ -20,11 +20,28 @@
     $ vagrant ssh
     $ cd ~/vagrant
     $ redis-server &
-    $ python3 app.wsgi
+    $ python app.py
     ```
 
 4.  access <http://127.0.0.1:3000/>
 
+## How to run on GAE local dev server (work in progress, as we did not fully migrate to GAE yet)
+
+1.  setup GAE SDK
+
+  - Install [GAE Python SDK](https://cloud.google.com/appengine/downloads)   
+
+2.  start GAE local dev server
+
+    do not forget the last dot (.) in the command
+
+    ```
+    $ dev_appserver.py .
+    ```
+
+4.  access <http://127.0.0.1:8080/>
+
+
 ## i18n/l10n
 
 ### Extract translatable strings from templates

app.py

@@ -68,9 +68,15 @@ def googlemap_api_key(self):
 
 octav = Octav(**cfg.section('OCTAV'))
 
-cache = cache.Redis(**cfg.section('REDIS_INFO'))
+backend = os.getenv('CACHE_BACKEND', 'Redis')
+if backend == 'Redis':
+    cache = cache.Redis(**cfg.section('REDIS_INFO'))
+elif backend == 'Memcached':
+    cache = cache.Memcached(**cfg.section('MEMCACHED'))
+else:
+    raise Exception('Unknown backend "%s"' % backend)
 
-twitter = oauth.Init('twitter', 
+twitter = oauth.Init('twitter',
     base_url='https://api.twitter.com/1.1/',
     request_token_url='https://api.twitter.com/oauth/request_token',
     access_token_url='https://api.twitter.com/oauth/access_token',

app.yaml

@@ -0,0 +1,16 @@
+application: confweb
+version: 1
+runtime: python27
+threadsafe: yes
+api_version: 1
+
+handlers:
+- url: .*
+  script: app.app
+
+libraries:
+- name: jinja2
+  version: latest
+
+env_variables:
+  CACHE_BACKEND: 'Memcached'

appengine_config.py

@@ -1,2 +1,12 @@
-import vendor
-vendor.add('lib')
+import os
+import sys
+
+from google.appengine.ext import vendor
+
+vendor.add('lib')
+
+# Fix for msvcrt import error https://github.com/gae-init/gae-init/pull/527
+# Otherwise, GAE local dev server fails at "import msvcrt" in "click" package
+if os.name == 'nt':
+    os.name = None
+    sys.platform = ''

cache.py

@@ -2,6 +2,11 @@
 
 import pickle
 import redis
+import os
+if os.getenv('SERVER_SOFTWARE', '').startswith('Google App Engine/') or os.getenv('SERVER_SOFTWARE', '').startswith('Development/'):
+    from google.appengine.api import memcache
+else:
+    import memcache
 
 class Redis(object):
     def __init__(self, host, port, db):
@@ -16,3 +21,33 @@ def get(self, key):
             return None
 
         return pickle.loads(thing)
+
+class Memcached:
+    def __init__(self, servers=[], debug=0):
+        if os.getenv('SERVER_SOFTWARE', '').startswith('Google App Engine/') or os.getenv('SERVER_SOFTWARE', '').startswith('Development/'):
+            print "GAE memcache used"
+            self.client = memcache
+        else:
+            def server_str(server):
+                host = server.get('host')
+                port = server.get('port')
+                if not host:
+                    raise Exception("host missing in memcache servers settings" )
+                elif not port:
+                    raise Exception("port missing in memcache servers settings" )
+                else:
+                    return str(  host + ':' + port )
+
+            if not servers:
+                raise Exception("servers missing in memcache settings")
+            else:
+                server_settings = map( server_str, servers )
+            print "Normal memcache used"
+            self.client = memcache.Client(server_settings, debug)
+
+    def set(self, key, val, expires=0):
+        self.client .set(key, val, expires)
+
+    def get(self, key):
+        return self.client.get(key)
+

config.json.default

@@ -8,6 +8,15 @@
         "port": 6379,
         "db": 0
     },
+    "MEMCACHED": {
+        "servers" : [
+            {
+                "host": "localhost",
+                "port": "11211"
+            }
+        ],
+        "debug": 0
+    },
     "OCTAV": {
         "endpoint": "",
         "key": "",

provision.mk

@@ -54,6 +54,7 @@ ubuntu-all:
 ubuntu-root: \
 	ubuntu-apt \
 	ubuntu-redis \
+	ubuntu-memcached \
 	ubuntu-pip
 
 ubuntu-user: \
@@ -75,6 +76,9 @@ ubuntu-apt:
 ubuntu-redis:
 	apt-get install -y redis-server
 
+ubuntu-memcached:
+	apt-get install -y memcached
+
 ubuntu-pip:
 	apt-get install -y python-pip
 	pip install -r /vagrant/requirements.txt

requirements.txt

@@ -5,6 +5,7 @@ flask_oauth
 jinja2
 py-gfm
 redis
+python-memcached
 urllib3
 wsgi-request-logger
 werkzeug