Will appengine work in China? - google-app-engine

A couple of our clients want to know - looking at some posts about there is inconsistent information.
http://code.google.com/p/googleappengine/issues/detail?id=1144

The answer is "No", for now and long after.
of cz google support his service in china,
but not china gov.
appspot is blocked by a big firewall around china.
by the way, it works when Obama visitting china.

Based on tests I conducted it appears that App Engine itself is not blocked in China, but the appspot.com domain is. So if you can use your own domain then App Engine should work fine for you.
In fact, if you use yourapp.appsp0t.com (with a zero instead of an o) then it seems to work as well at the moment, although I would not really recommend relying on this work-around in the long run; it opens your app and your users to Man in the Middle (MITM) attacks from whoever runs appsp0t.com.
Here are some tools you can use to check availability and performance from China:
http://www.greatfirewallofchina.org/
http://www.websitepulse.com/help/testtools.china-test.html
http://www.dotcom-monitor.com/WebTools/website-speed-test.aspx

Not directly, since Google DNS server is blocked by 'Great Firewall', therefore one cannot reach myapp.appspot.com within China.
However, you can work around by setting up a reverse-proxy server, which redirects myapp.com to myapp.appspot.com.

What about using custom domain name?
This will get around the DNS resolution. But is the google IP address range allocated for appengine blocked by china? If so, you then you have to use the reverse proxy solution.

Related

Serve Files From Naked Root Domain

I run Google Ads on my Google-App-Engine-hosted website (www.bigriddles.com), and they tell me I need to have an "ads.txt" file served from the root domain (i.e. http://bigriddles.com/ads.txt, as opposed to http://www.bigriddles.com/ads.txt).
My DNS is hosted on Gandi, and I created their "ALIAS" record (which I think just does CNAME flattening or something similar) to alias "bigriddles.com" to "ghs.googlehosted.com." I chose "ghs.googlehosted.com" because that's what I CNAMEd "www.bigriddles.com" to (many years back), and that CNAME has been working fine.
However, now when I visit "bigriddles.com", I get an "HTTP 301 Moved" to "www.bigriddles.com", and as far as I can tell, this response isn't coming from any code I wrote (I've looked through my code and don't see anything that would redirect this). Furthermore, there is a "Server: ghs" header in the response from "bigriddles.com", whereas if I visit "www.bigriddles.com", which works fine, the response includes the header "Server: Google Frontend". I'm not sure if there is some hint of my problem in the difference between those two Server headers.
Anyway, I'm not sure exactly what's going wrong. It could be a DNS issue. I say this because "dig www.bigriddles.com" comes back with the IP 172.217.14.115, whereas "dig bigriddles.com" comes back with "172.217.168.211", so maybe one of these really is a "ghs" server and the other is a "Google Frontend" server (I'm not sure the difference) and this "ALIAS" DNS solution just isn't going to work.
More likely though I feel like maybe there is just some settings problem with my App itself where it's not set up to allow the apex domain "bigriddles.com", and if I change that setting it will start working?
I have gone through the steps on https://cloud.google.com/appengine/docs/standard/python/mapping-custom-domains. When I view the "Custom Domains" for my project, I see "www.bigriddles.com" and "m.bigriddles.com", but I don't see the naked domain "bigriddles.com". However, when I try to add it on that page, it tells me that "bigriddles.com" is already mapped to a project, so I'm not sure what to make of that.
Any help would be appreciated, thank you!
This seems like an issue with your domain provider.
You can use this tool that might help you contact the domain provider with detailed info.
If they insist it's not an issue on their side (I strongly believe it is), then you should contact Google Cloud Platform Support so a deeper inspection can be made on your project.
If you're also using G Suites for your domain, the criminal is G Suites' Domain -> Redirect. If it is, it's a pity that Google does not let us turn off the so-called feature.
Since G Suites use as the same entry point as App Engine, you have no chance to solve this other than moving your site outside Google services or stop using G Suite.

GAE urlfetch Host header set to IP address instead of hostname

I am calling a third party web service from app engine. This particular service is picky. I ran into an issue where calls would work fine for a while, then stop working, then start working again. I realized that if I manually stopped all instances in the admin console, that the calls would work again.
I setup a proxy to route the calls through that so I could see the headers and all detail. I think I have tracked the issue down to the following. After an instance has been up for a while (the app usually just needs 1 to 3 instances right now) app engine will start using the IP address of the destination as the value for the host header instead of the hostname. Well the service doesn't like that. Whether it should care is another matter.
So my question is, why does app engine use the ip address for the host header eventually instead of the hostname? And, of course, is there anything I can do about it? I know that I cannot set the host header, but maybe there is something else that can be done.
Thanks for any insight.
First, thank you for finding this behavior. We have had intermittent issues with urlfetch for a long time, and will try to detect if this is the issue.
One thing you could try is to target a specific instance/module:
http://instance.version.module.app-id.appspot.com
and cycle through the instances. If you just target the module, it will kill the instance after some inactivity. So, perhaps that would not trigger the GAE DNS shortcut.
Another trick would be to add a fake, random, query string after your url: ?foo=D7hfka67h. Perhaps that would prevent GAE from recognizing the repeat url, and trying to shortcut the DNS.

Redirect loop when logging in to appengine

(yes - cross-posted from the google-appengine google group...I can't tell if they answer support questions like this there or here or what...it's all kind of a mess :) )
I am having a problem logging in to the appengine console using certain accounts on my google apps domain (but not others).
No matter what browser I use (Firefox, Chrome, Safari, IE), I get a "too many redirects" error on https://appengine.google.com/start when I try to log in using a specific account. I have tried resetting all the browsers as well (clearing all cookies, cache, etc - even trying it on a clean install of an OS) - with no luck. Going directly to https://appengine.google.com/a/domain.name causes the same loop for those accounts. The same thing happens when running the browsers with privacy mode enabled.
One of the accounts having problems is the user nathan.toone on the k9webprotection.com google apps domain - however we can log in with the user "admin" or the user "build-agent" on the same domain just fine (but not "build.agent" or "user2"). It seems to be all over the place as to which accounts are able to log in without the redirect loop and which ones aren't.
I have contacted google apps for your domain support, and they have said that it is outside their scope. They very "helpfully" pointed me to https://developers.google.com/appengine/kb/general - which didn't help AT ALL. :(
Again - the odd thing is that there are some of the accounts on the same domain that are able to log in just fine. Does anyone have any idea what could be happening, or have a way for me to contact someone to get this worked out? I have found a couple of other people saying they have had this problem, but have not been able to encounter a solution.
-Nathan

How do i get foo.somedomain.com get handled by myapp.appspot.com/foo on appengine

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

Using a subdomain to identify a client

I'm working on building a Silverlight application whereas we want to be able to have a client hit a url like:
http://{client}.domain.com/
and login, where the {client} part is their business name. so for example, google's would be:
http://google.domain.com/
What I was wondering was if anyone has been able, in silverlight, to be able to use this subdomain model to make decisions on the call to the web server so that you can switch to a specific database to run a query? Unfortunately, it's something that is quite necessary for the project, as we are trying to make it easy for their employees to get their company specific information for our software.
Wouldn't it work to put the service on a specific subdomain itself, such as wcf.example.com, and then setup a cross domain policy file on the service to allow it to access it?
As long as this would work you could just load the silverlight in the proper subdomain and then pass that subdomain to your service and let it do its thing.
Some examples of this below:
Silverlight Cross Domain Services
Silverlight Cross Domain Policy Helpers
On the server side you can check the HTTP 1.1 Host header to see how the user came to your server and do the necessary customization based on that.
I think you cannot do this with Silverlight alone, I know you cannot do this without problems with Javascript, Ajax etc. . That is because a sub domain is - for security reasons - treated otherwise than a sub-page by the browsers.
What about the following idea: Insert a rewrite rule to your web server software. So if http://google.domain.com is called, the web server itself rewrites the URL to something like http://www.domain.com/google/ (or better: http://www.domain.com/customers/google/). Would that help?
Georgi:
That would help if it would be static, but alas, it's going to all be dynamic. My hope was to have 1x deployment for the application, and to use the http://google.domain.com/ idea to switch to the correct database for the user. I recall doing this once when we built an asp.net website, using the domain context to figure out what skin to use, etc.
Ates: Can you explain more about what you are saying... sounds like you are close to what I am trying to come up with. Have you seen such a tutorial for this?
The only other way I have come up with to make this work is to have a metabase that when the user logs in, it will switch them to the appropriate database as required... was just thinking as well that telling Client x to hit:
http://ClientX.domain.com/ would have been sweeter than saying to hit http://www.domain.com/ and login. It seemed as if they were to hit their name, and to show it personalized for them right from the login screen would have been much more appealing for the client base.
#Richard B: No, I can't think of any such tutorial that I've seen before. I'll try to be more verbose.
The server-side approach in more detail:
Direct *.example.com to the same IP in your DNS settings.
The backend app that handles login checks the Host HTTP header (e.g. the "HTTP_HOST" server variable in some platforms). That would contain the exact subdomain.example.com that the client used for reaching your server. Extract the subdomain part and continue...
There can also be a client-side-only approach. I don't know much about Silverlight but I'm assuming that you should be able to interface Silverlight with JavaScript. You could read document.location with JavaScript and pass it to your Silverlight applet, whereon further data fetching etc. logic would rely on the subdomain that was passed in by JavaScript.
#Ates:
That is what we did when we wrote the ASP.Net system... we pushed a slew of *.example.com hosts against the web server, and handled using the HTTP headers. The hold-up comes when dealing with WCF pushing the info between the client and the server... it can only exist in one domain...
So, for example, when you have {client}.example.com and {sandbox}.example.com, the WCF service can't be registered to both. It also cannot be registered to just *.example.com or example.com, so that's where the catch 22 is coming in at. everything else I have the prior knowledge of handling.
I recall a method by which an application can "spoof" another domain name in certain instances. I take it in this case, I would need to do such a configuration? Much to research yet I believe.

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