I'm developing a Java app in GAE, which offers an API through Google Cloud Endpoints.
Basically it receives requests in the endpoints and uses a number of web services from different providers, stores some data and returns some data through the endpoints...
I understand that my app is conceptually a backend, because it doesn't provide any web page, but only the endpoints, don't you think so?
But there's no way to create only a backend, without being associated to any frontend app, is there? At least Google Plugin for Eclipse only allow you to "Generate App Engine Backend", from an existing app, and moreover this app must be an Android project...
I'm using it as a frontend and there's no problem, but apart from the conceptual issue, I've read that backends are kind of optimized to be backends, with more memory and CPU...
I think you're just confused because the Cloud Endpoints documentation uses the word 'backend' to refer to the entire cloud-hosted server implementation. It doesn't specifically refer to the use of GAE backend instances. Endpoint requests can be served by frontend or backend instances, based on how you set them up and the url being accessed.
From the App Ending docs:
"When an application is called to serve a web request, it must issue a response within 60 seconds"
"App Engine Backends are instances of your application that are exempt from request deadlines and have access to more memory (up to 1GB) and CPU (up to 4.8GHz) than normal instances."
So unless you're requests are doing something crazy, you don't need to use a backend. In the google-plugin-for-eclipse, "generate appengine backend" is talking about creating a backend for your android app... a server for your android app to contact (in this case your android app is the frontend and you're appengine app is the backend). In the example app you can remove the web side (index.html) to the appengine application and you'll have no web frontend. Index.html is using the gapi javascript library to make endpoints calls to your appengine service.
Related
I have a frontend project and a backend project. These are 2 separate app engine projects.
Setting up IAP on both is not problem but when my frontend project tries to call the backend project it is blocked.
Is there anyway to have access allowed to the backend project when the user passes the frontend IAP ? or do I have to leave the backend project without IAP enabled ?
You have to programmatically invoke (make the call using an OIDC token) to the backend from your front end. See documentation on how to do that.
There are misunderstandings. Let me clarify.
Firstly, your App Engine is highly scalable in a single project. Instead of having several projects with several App Engine, you should have only one project, with a single App Engine and multiple services.
Default is usually used for the frontend part. You can use an API service for your backend, or name it as you wish.
Like that, the whole website will be protected by the same IAP context. Like that, no issue as you have before, it's the same IAP cookies and the API calls should not create issues.
Secondly, keep in mind that your JS code runs in the client browser, not on App Engine; App Engine only serves the static files, that's all. All the rest of the computation is performed locally.
I have an API running in Google App Engine and I want to introspect HTTP POST body to reject poorly formed calls before it hits my API running in app engine. Is there a way to front an App Engine application whereby I can introspect the URI, the POST body and return a 400 without it actually being processed by my code running in App Engine? Please let me know, thanks.
If you want to inspect HTTP, then you will need to write a proxy application to do so. Neither the Google Cloud Load Balancer nor App Engine support hooking HTTP requests.
Proxies have the MITM (Man In The Middle) problem in that HTTP traffic is often encrypted. You will not be able to inspect that traffic unless your proxy is the endpoint. If you implement your proxy with Apache or Nginx then you can use the ModSecurity project.
Basically, you want to implement a WAF. Google offers Cloud Armor which supports inspecting traffic via Cloud Armor rules.
We are looking to use Google App Engine for one of our low latency service. We are required to provide low latency service across the globe. Since Google App Engine is a regional service and there is no straight forward way to deploy it multi-regional. So, looking at Google Load Balancer to route at DNS level, but that also does not seems to be possible as load balancer not supporting App Engine as a backend service. Is there any other way to achieve GeoDNS routing in GCP for App Engine service.
There is not an direct way to achieve GeoDNS routing since App Engine is a regional service, as you said.
Read this feature request to have further insight on this. In the second comment they state the two possible workarounds, useful for both standard and flexible environments:
The workaround is how you mentioned, using a single project with a load balancer to route requests to Compute Engine instances in
different regions. Then have each Compute Engine instance act as
proxies to an App Engine project in each of the different regions
(where you would copy your code to each App Engine project).
It may be easier in the meantime to use Google Kubernetes Engine instead of App Engine for multi-regional application serving.
You could star the FR to support it.
I've been trying to do this for a while, but I'm confused as to the difference between the two applications.
I know that endpoints helps you expose an API and generate the client libraries that allow you to interact with your Android app.
But in the examples, it seems as though endpoints is the only code you write for the backend at all.
I thought that app engine was what the actual application ran on - that is, do I need a separate project with the app engine backend, then my android studio project with the Android app and the endpoints API, or does writing the endpoints API also serve as the app engine backend?
The endpoints backend API is just a piece of a GAE app functionality.
If you only have that functionality in your app you can extend it by adding the desired stuff to the existing app.yaml file (and the related app code), you don't have to create a new app. Especially if the endpoints functionality and the additional desired functionality are related.
You can also add endpoints backend support to an existing GAE app by merging the endpoints backend app.yaml content into the existing app's app.yaml file and adding the class file and API server file to the app's code.
I have been developing a Phonegap client application, I need to create a web service that storage all the data that i will be sending through the app.
I want to use google app engine to create the database and the web service.
I have read a lot, but i don't find a concrete example of how to do it and how to call the web service then from the application with phonegap.
Anyone have an example of how to do this?
You can use Cloud Endpoints with your app:
Google Cloud Endpoints consists of tools, libraries and capabilities
that allow you to generate APIs and client libraries from an App
Engine application, referred to as an API backend, to simplify client
access to data from other applications. Endpoints makes it easier to
create a web backend for web clients and mobile clients such as
Android or Apple's iOS.
For mobile developers, Endpoints provides a simple way to develop a
shared web backend and also provides critical infrastructures, such as
OAuth 2.0 authentication, eliminating a great deal of work that would
otherwise be needed. Furthermore, because the API backend is an App
Engine app, the mobile developer can use all of the services and
features available in App Engine, such as Datastore, Google Cloud
Storage, Mail, Url Fetch, Task Queues, and so forth. And finally, by
using App Engine for the backend, developers are freed from system
admin work, load balancing, scaling, and server maintenance.
It is possible to create mobile clients for App Engine backends
without Endpoints. However, using Endpoints makes this process easier
because it frees you from having to write wrappers to handle
communication with App Engine. The client libraries generated by
Endpoints allow you to simply make direct API calls.
Available in Python | Java
we have done similar thing for our Cordova/ionic based application. Its very simple and straight forward using javascript client of google cloud endpoint.