specify custom dns server on gae - google-app-engine

I have a gae application that needs to consume a third party api. That api is accessible via a url that can only be resolved through use of a dns server supplied by that third party.
Is there any way for me to point my gae application at that specific DNS server instead of the default ones?
I assume the answer is no, but it's a difficult thing to google for because I keep getting search results about how to set up a custom domain.

The dnspython package supports queries while specifying the nameservers to use, see
Set specific DNS server using dns.resolver (pythondns).
It does use sockets, though, which are only available to paid apps. There were some problems reported with it a while back, but they appear to be resolved, I guess it's worth a try (personally I didn't use it).
Related: [google-app-engine] dnspython

Related

Need a workaround for mapping domain to appengine

I'm trying to follow this tutorial here, but I can't complete the verification step (#4). My domain provider doesn't allow me to add a DNS record for the type AAAA. I tried contacting my domain provider but they say it's not supported. Is there another work around I could do? Should I try using another cloud hosting service like Azure?
You can use the features and capabilities that Cloud DNS offers. No need for switching Cloud hosting services.
Cloud DNS is a high-performance, resilient, global Domain Name System (DNS) service that publishes your domain names to the global DNS in a cost-effective way.
Migrate to Cloud DNS an existing DNS domain from another DNS provider.
Then, Managing Records will make it easy for you to add and remove a record. This is done by using a transaction that specifies the operations you want to perform. A transaction supports one or more record changes that are propagated together.
Update
I would also check out Google Domains, which is a fairly new service (still in Beta) and allows you to register your domain name and works like a charm.

Is there a way to ban IP addresses from accessing my parse-server?

If a particular computer is making tons of accounts or flooding my server with other requests, could parse-server automatically check this behaviour and block the specified IP address?
Built-in rate limiting would also be a nice alternative, although it doesn't really solve the problem if the person continues to spam.
I am hosting on google app engine by the way.
I don't know about Parse itself, but from App Engine side you have DoS protection service controlled via dos.yaml file in your project that lets you blacklist IP blocks—sounds like that may help. It's not "automatic", though; you still need to manually update this file and issue appcfg.py update_dos <PROJECT_DIR> for changes to take effect.
I don't believe that this is a feature out of the box - see advanced options here: https://github.com/ParsePlatform/parse-server.
You'd need to look at controlling access to the Google App Engine (or another host - such as Microsoft Azure Web App) using a firewall (you can easily do this with Azure. I'm not familiar with Google App Engine, but imagine similar functionality is available.
However, I don't believe that a firewall is necessary - just better app security. Disable anonymous users - Parse Server Security

Design: using a backend server to circumvent great firewall of china

I have a front-end angular app using firebase to store user data.
I currently do not have a backend set up, such as a node.js server.
I would like to use the Google Docs API to upload files from my app.
Since the Great Firewall of China does not (or makes unstable) the use of Google services, is it possible to place those services on the backend server and still use them reliably?
Perhaps after they have uploaded the document to firebase, a backend script retrieves it, uploads it to google docs, and then removes the record from firebase? Just trying to see if Google or similar services are even feasible for this use case.
I suppose the crux of my question is whether or not the calling of the Google API would be taking place on the user's computer, in which case would it become unstable?
** Updates for clarity:
I am deciding whether my firebase-backed app needs a more traditional backend like a node server to do things like: upload images and documents, send mail via Mandrill, etc... It would be helpful to me if I knew whether, after putting in the time to create a server, some of the services I am after (aka APIs) are any more resilient to the GFW than they would be if they ran on the client side. So if any one has had success in such a task, I would like to know.
** Technical update:
So, for example, if I run the Google Maps API on the client side, if the user is in China and is not running a VPN, accessing the API calls will either lag or time out or (rarely) success in returning the scripts. If I was somehow able to able to process the map query "off-site" aka on the server, could I then return with a static image of the map to a Chinese user without fail?
If I was somehow able to able to process the map query "off-site" aka
on the server, could I then return with a static image of the map to a
Chinese user without fail?
Yes, of course. What you are going to miss this way is all the front-end interactive functionality Google Maps offers. But if that's ok in your use case, sure.
I have never tried it with the GCF, but what I would do is this:
Google Maps <-> Your Reverse proxy <-> User
So, instead of the user visitng the real google maps site, it will be visiting your maps.mydomain.com site, that will be sitting in between, proxying everything.
Nginx is an excellent choice for a reverse proxy. If you need more control, there are good node.js reverse proxying packages that you an use to rewrite the content extensively before serving it (perhaps to obfuscate it in case the GCF blacklists content based on pattern matching, or to change the script names/links again to avoid pattern matching).
You are misunderstanding about the great firewall of China. I consulted for a couple of Chinese companies after the dot com crash so I can say this from personal experience, not hearsay.
It is mostly high-end Cisco hardware behind gateways behind their government telecom infrastructure. Nowadays they knock off what hardware they can, every chance they can, and spend money on specialized hardware to monitor cell phones systems.
There was a brief mention of the street-level surveillance hardware on 20/20 before the crash if you are interested in looking it up.
Not to discourage you, but I say set up whatever open servers you want with whatever frontends or backends you want, but the reality is the traffic is not going to be there.
That is why they call it an oppressive regime, they do not get to decide for themselves, remember?

traffic splitting in google app engine based on customer subdomain

When customers signup to my service (myservice.com), they get assigned a subdomain. So customer A would get a url to customerA.myservice.com, customer B would get a url like customerB.myservice.com etc.
I am working on a new version of the service, and would like to redirect some of the new customers to the new version to test the new version.
I know I can create different versions of the service, and split the traffic by ip and cookie between them. It is also possible to split traffic based on routing, but it seems, that in the end GAE still relies on either ip or cookie information to split the traffic: https://developers.google.com/appengine/docs/adminconsole/trafficsplitting#Routing. So if my customer accesses the my service on desktop, ipad and smartphone, he might sometimes get one version of my service on his desktop (at home) and another on his smartphone (on the road).
So my question is if it is possible to always direct customerA.myservice.com to one version of my service and customerB.myservice.com to another version, regardless of device, cookie or ip?
thanks
Thomas
It's not possible with Traffic Splitting feature of App Engine, but you can implement this logic yourself. When users hit your domain, you can choose which version of the app to serve them. There are three drawbacks:
It won't look pretty - the URLs pointing to individual versions may be confusing.
Users might bookmark the version URL, and later they will get an error when they hit it, if the version is no longer available.
You have to make sure that all URLs in your app are relative, if they point to your domain. Otherwise you might link across different versions.
Also, some versions may not be compatible due to the changes in the data model, i.e. you cannot run them in parallel.
Similar issues also arise with the App Engine's splitting - or any other traffic splitting. This is why I recommend to have a trusted group of your most enthusiastic users. Send them a new version as a "preview" and ask for their feedback. They will appreciate you reaching out to them, and they will not be confused if they hit a different version on a different device.

Many Custom Domains for AppEngine Instance

For our e-commerce service running on AppEngine we would like to offer the option for customers to run the stores on their custom domains (eg: www.mystore.com instead of www.enstore.com/mystore).
From a user perspective, I'd like them to enter the domain name they want to use in their preference screen and tell them how to configure their dns.
I know how you normally add domains to an AppEngine instance (through Google Apps) but I'm not sure you can automate that. And even if that's possible they would be all (hundreds) listed on our google apps page.
Anyone know if this is possible/if there is a good way to do it?
I don't think there is a way to add domains "programatically" to an AppEngine instance. Apparently, domains can only be added by using the Google Apps method that you described. This is confirmed in this SO post: How do i get foo.somedomain.com get handled by myapp.appspot.com/foo on appengine
The only options that pop to mind are the following:
HTTP Redirection
Many DNS providers support HTTP Redirection. In this case, your clients would be able to set up mystore.com and www.mystore.com to redirect to www.enstore.com/mystore. There are some obvious disadvantages with this method that might not be acceptable. First of all, with 301 and 302 redirects, the users will still be forwarded to the registered AppEngine URL: www.enstore.com/mystore, and it will show in their browser. In addition, choosing between a 301 and 302 redirect can make SEO tricky, since you'd have to get into how search engines behave with these redirects. For example most search engines will not use the original URL as a source for keywords when you use a 301 redirect.
In addition to 301 and 302 redirects, some DNS providers (like DNS Made Easy) also provide what they call a "masked hidden-iframe redirect". The page will render inside a hidden iframe, so the URL does not change in the user's browsers. However this makes SEO even more tricky, and it will not allow users to bookmark internal pages, or to reference them easily.
As you can see, this option is less than ideal, but it is one option to consider in some situations. Also note that at the moment, HTTP Redirection using 301 redirects is the suggested workaround for the Naked Domain Issue 777 on the AppEngine issue tracker.
Reverse Proxy
Another option could be to set up a small server somewhere else, like a small Amazon EC2 Instance, and set up a simple reverse proxy. You would be able to set this up very easily, just by using Apache and mod_proxy (or various other alternatives). This would allow you to ask your clients to set up a normal A Record pointing to this instance, while the Apache HTTP server would be acting as a proxy to your AppEngine.
The fundamental configuration directive to set up a reverse proxy in mod_proxy is the ProxyPass. You would typically set it up with one line like these for each VirtualHost (for each client domain):
ProxyPass / http://www.enmystore.com/mystore/
The configuration of the remote proxy could be easily handled by your back-end software.
This is a neater solution which gives you plenty of control - but there are obviously some costs for these benefits. First of all, there is the expense to host the reverse proxy. You would also be adding another point of failure, so you have to add this to your high-availability plan. In addition, if you are serving some pages through SSL it can become quite complicated.
Another option is to have each customer sign up for google apps, and then add your appengine app to their app. That way they can manage the url. They will need to use a cname for this, so urls will be limited to something like 'store.customer.com' You will have to support the multitenancy off of the host-header, but that isn't hard to do given that you already have a way to support multitenancy already. You might want to do the setup for the first couple of clients yourself so you can document the easiest way to set it up.
The rietveld code review app does this as you can add it to your google apps domain. See http://code.google.com/p/rietveld/wiki/CodeReviewHelp#Using_Code_Reviews_with_Google_Apps for more detail.
The preferred option is probably to offer your solution through the Google Solutions Marketplace: http://www.google.com/enterprise/enterprise_marketplace/about.html
We did something similar to Daniel Vassallo second proposal.
We created a python app on the Heroku cloud
(there is no limit for connecting custom domains).
This app is using python requests 1.2.0 lib to get the correct page from your app engine application according to the request domain.
all you need to tell your clients is to put your Heroku app url as their CNAME
For naked domains you can always use wwwizer

Resources