I'm a designer still trying to code up my first app in Google App Engine as an experiment.
I have got to the point where I want to set up memcache to cache my entire site following the instructions at: http://docs.djangoproject.com/en/dev/topics/cache/#memcached
I am clear that I need to add in my settings.py the following:
CACHE_BACKEND = 'memcached://[IP ADDRESS]:[PORT]/'
And then:
MIDDLEWARE_CLASSES = (
'django.middleware.cache.UpdateCacheMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.cache.FetchFromCacheMiddleware',
)
CACHE_MIDDLEWARE_SECONDS=60*2
This might be a really dumb question but what would my IP address and port be for my google app engine site? Is there any considerations I need to make because of the fact that it is being hosted at Google?
How would I find it out
djangoappengine has standard settings. At the top of your settings.py you should have "from djangoappengine.settings_base import *". You can take a look at the settings_base module to see all backends and default settings.
Try: CACHE_BACKEND = 'memcached://?timeout=0'.
Source: http://bitbucket.org/wkornewald/djangoappengine/src/tip/settings_base.py
Related
Whilst developing I want to handle some things slight differently than I will when I eventually upload to the Google servers.
Is there a quick test that I can do to find out if I'm in the SDK or live?
See: https://cloud.google.com/appengine/docs/python/how-requests-are-handled#Python_The_environment
The following environment variables are part of the CGI standard, with special behavior in App Engine:
SERVER_SOFTWARE:
In the development web server, this value is "Development/X.Y" where "X.Y" is the version of the runtime.
When running on App Engine, this value is "Google App Engine/X.Y.Z".
In app.yaml, you can add IS_APP_ENGINE environment variable
env_variables:
IS_APP_ENGINE: 1
and in your Python code check if it has been set
if os.environ.get("IS_APP_ENGINE"):
print("The app is being run in App Engine")
else:
print("The app is being run locally")
Based on the same trick, I use this function in my code:
def isLocal():
return os.environ["SERVER_NAME"] in ("localhost", "www.lexample.com")
I have customized my /etc/hosts file in order to be able to access the local version by prepending a "l" to my domain name, that way it is really easy to pass from local to production.
Example:
production url is www.example.com
development url is www.lexample.com
I just check the httplib (which is a wrapper around appengine fetch)
def _is_gae():
import httplib
return 'appengine' in str(httplib.HTTP)
A more general solution
A more general solution, which does not imply to be on a Google server, detects if the code is running on your local machine.
I am using the code below regardless the hosting server:
import socket
if socket.gethostname() == "your local computer name":
DEBUG = True
ALLOWED_HOSTS = ["127.0.0.1", "localhost", ]
...
else:
DEBUG = False
ALLOWED_HOSTS = [".your_site.com",]
...
If you use macOS you could write a more generic code:
if socket.gethostname().endswith(".local"): # True in your local computer
...
Django developers must put this sample code in the file settings.py of the project.
EDIT:
According to Jeff O'Neill in macOS High Sierra socket.gethostname() returns a string ending in ".lan".
The current suggestion from Google Cloud documentation is:
if os.getenv('GAE_ENV', '').startswith('standard'):
# Production in the standard environment
else:
# Local execution.
Update on October 2020:
I tried using os.environ["SERVER_SOFTWARE"] and os.environ["APPENGINE_RUNTIME"] but both didn't work so I just logged all keys from the results from os.environ.
In these keys, there was GAE_RUNTIME which I used to check if I was in the local environment or cloud environment.
The exact key might change or you could add your own in app.yaml but the point is, log os.environ, perhaps by adding to a list in a test webpage, and use its results to check your environment.
I followed the Getting started with Laravel on PHP for App Engine and I'm getting an error when I change the path of the Storage to Google Cloud Storage in local development.
ex.
const BUCKET_NAME = "bucket-name";
$storage_path = "gs://" . BUCKET_NAME . "/storage";
Here is the ErrorException:
file_put_contents(/meta/services.json): failed to open stream: No such file or directory
App Engine doesn't allow you to write to the local filesystem for security and scalability reasons. Fortunately though you can read and write to Google Cloud Storage easily using commands like file_put_contents(). This facility is also emulated in the local dev_appserver.
Take a look at https://github.com/ajessup/laravel for a version of Laravel that's been tweaked to run well on Google App Engine, including writing /meta/services.json to GCS.
This might help.
http://forumsarchive.laravel.io/viewtopic.php?id=9341
"By defining the manifest path in app/config/app.php to point to a Cloud Storage path instead, like this: 'manifest' => 'gs://yourbucketname' .'/meta',"
Looks like storage_path() issue when 'manifest' => storage_path().'/meta',
Now I use my own Java FTP program to ftp objects from my PC to my ISP's website server.
I want to use Google App Engine's servlet to get Paypal IPN messages, then store the messages into my own objects and ftp the objects to my ISP's website server, is this doable ? I heard Google App Engine doesn't support FTP.
I don't expect Google to do it for me, but can I use my own Java FTP program in the web app that I upload onto the App Engine to do it ?
Frank
No, you can't open any socket connection except by using URL Fetch
service on HTTP/HTTPS to these port ranges:
80-90, 440-450, 1024-65535.
As of April 9 this year (SDK 1.7.7) this isn't a problem any longer. Outbound sockets (e.g. FTP) are generally available to all billing-enabled apps.
Socket API Overview (Java): https://developers.google.com/appengine/docs/java/sockets/
UPDATE: Our code below may no longer work. This FTP code worked for us before but we see a comment now below that says FTP is no longer supported on App Engine. See the link below. If you try this code and it works or doesn't work for you for straight FTP (TLS is NOT supported BTW) - please comment.
Yes. FTP now works on Google App Engine. (The accepted answer is outdated and no longer true.)
Here is tested and working code on GAE.
#!/usr/bin/env python
from google.appengine.ext import webapp
from ftplib import FTP
class HwHandler(webapp.RequestHandler):
def get(self):
self.response.out.write('FTP Starting...<br>')
ftp = FTP('ftp_site.com')
ftp.login('login', 'password')
ftp.retrlines('LIST') # list directory contents
self.response.out.write('FTP opened')
ftp.quit()
app = webapp.WSGIApplication([
('/', HwHandler)
], debug=True)
Of note, FTP TLS does not appear to work currently. (Trying to do "from ftplib import FTP_TLS" fails.)
You can use the Apache Commons FTP client (org.apache.commons.net.ftp.FTPClient) if you put it into passive mode. Just do the following:
FTPClient client = new FTPClient();
client.connect(FTP_HOST);
client.enterLocalPassiveMode();
Then it won't call ServerSocketFactory, and life should be good!
Here is what I'd like to achieve
http://foo.somedomain.com gets handled by
http://myapp.appspot.com/foo (google appengine app myapp)
and the underlying url is masked.
Note the following:
somedomain.com is a third party domain that would like to add foo.somedomain.com
mydomain.com would be CNAME'd to myapp.appspot.com
mydomain.com/foo would point to myapp.appspot.com/foo
other scenarios
can foo.mydomain.com be made to point to myapp.appsot.com/foo
can foo.somedomain.com point directly to myapp.appspot.com/foo
Added: myapp.appspot.com is developed using django w/ app-engine-patch
You can't do this in the way described. In order to do this, you need to:
CNAME foo.somedomain.com to ghs.google.com (not to myapp.appspot.com)
Set up Google Apps for your Domain on somedomain.com, if it's not already
Add the app 'myapp' to foo.somedomain.com through the Apps control panel
Once that's done, your app can check self.request.host to determine which hostname was sent, and route requests appropriately.
You can parse the sub-domain from the Host header, then call the webapp.RequestHandler appropriate for the path /[sub-domain], assuming *.yourdomain.com is directed to the Google App Engine application.
Have a look at webapp.WSGIApplication and see if there's a way to get the mapped webapp.RequestHandler for a path. Alternatively, you might be able to modify the request object to change the requested path (this I'm not sure about, however.)
This question was asked in one of the 2009 Google I/O app engine talks. Unfortunately the answer given was along the lines of not supported at this time but the possibilities of some workarounds may exist. 2009 Google I/O videos
The CherryPy web server can supposedly be deployed in the Google App Engine.
Who has done it, and what was the experience like?
What special effort was required (configuration, etc.)?
Would you recommend it to others?
The article is a good example but its slightly out of date now as the patch is no longer required, the latest version of Cherrypy should run without it, I've gotten the sample below running in the development environment.
I've included cherrypy inside a zip file as the google app engine has a limit of one thousand files per application, it also makes it easier to deploy.
I'm also using the cherrypy dispatch handler to route the request.
import sys
sys.path.insert(0, 'cherrypy.zip')
import cherrypy
import wsgiref.handlers
class Root:
exposed = True
def GET(self):
return "give a basic description of the service"
d = cherrypy.dispatch.MethodDispatcher()
conf = {'/':
{
'request.dispatch': d
}
}
app = cherrypy.tree.mount(Root(), "/",conf)
wsgiref.handlers.CGIHandler().run(app)
So far I've not come across any particular issues but I have read some people have had issues with sessions.
See boodebr.org article (missing, but here on the Wayback machine) It works for me.
If you are looking for an example, look for the condition that accepts ServerMode.GAE in ServerInterface.auto in this example.
There is a good article on how to do this over here now here. I haven't actually tried this yet, I stuck with django on App Engine, but it seems to be a solid example.