Add support for third-party memcache (#600)

Author: Jon Wayne Parrott

appengine/flexible/memcache/README.md

@@ -20,6 +20,6 @@ Start your application:
 
 Deploy using `gcloud`:
 
-    gcloud beta app deploy app.yaml
+    gcloud app deploy
 
 You can now access the application at `https://your-app-id.appspot.com`.

appengine/flexible/memcache/app.yaml

@@ -5,5 +5,14 @@ entrypoint: gunicorn -b :$PORT main:app
 runtime_config:
   python_version: 3
 
-beta_settings:
-  enable_app_engine_apis: true
+# [START env_variables]
+env_variables:
+  # If you are using the App Engine Memcache service (currently in alpha),
+  # uncomment this section and comment out the other Memcache variables.
+  # USE_GAE_MEMCACHE: 1
+  MEMCACHE_SERVER: your-memcache-server
+  # If you are using a Memcached server with SASL authentiation enabled,
+  # fill in these values with your username and password.
+  MEMCACHE_USERNAME: your-memcache-username
+  MEMCACHE_PASSWORD: your-memcache-password
+# [END env_variables]

appengine/flexible/memcache/main.py

@@ -16,16 +16,26 @@
 import os
 
 from flask import Flask
-from pymemcache.client.base import Client as MemcacheClient
-
+import pylibmc
 
 app = Flask(__name__)
 
 
 # [START client]
-memcache_addr = os.environ.get('GAE_MEMCACHE_HOST', 'localhost')
-memcache_port = os.environ.get('GAE_MEMCACHE_PORT', 11211)
-memcache_client = MemcacheClient((memcache_addr, int(memcache_port)))
+# Environment variables are defined in app.yaml.
+if os.environ.get('USE_GAE_MEMCACHE'):
+    MEMCACHE_SERVER = ':'.join(
+        os.environ.get('GAE_MEMCACHE_HOST', 'localhost'),
+        os.environ.get('GAE_MEMCACHE_PORT', 11211))
+else:
+    MEMCACHE_SERVER = os.environ.get('MEMCACHE_SERVER', 'localhost:11211')
+
+MEMCACHE_USERNAME = os.environ.get('MEMCACHE_USERNAME')
+MEMCACHE_PASSWORD = os.environ.get('MEMCACHE_PASSWORD')
+
+memcache_client = pylibmc.Client(
+    [MEMCACHE_SERVER], binary=True,
+    username=MEMCACHE_USERNAME, password=MEMCACHE_PASSWORD)
 # [END client]
 
 

appengine/flexible/memcache/requirements.txt

@@ -1,3 +1,3 @@
 Flask==0.11.1
 gunicorn==19.6.0
-pymemcache==1.3.8
+pylibmc==1.5.1