Hosting multiple customer websites on Google App Engine - google-app-engine

Question

We currently host a large number of containerized websites in Kubernetes and we are exploring using Google App Engine to host these sites but we cannot figure out how to host a large number (hundreds) of websites in a single Google App Engine account.
At first glance it seemed that every website will be a separate project but then it became clear that there is a soft limit of twenty projects (and we might end up hosting hundreds of sites) so this did not seem to be the correct approach. We then explored using a single project with dispatch.yaml to route between the sites. Dispatch.yaml only allows for ten entries which mean that it will not work. Is there any other approach we are missing? Our dispatch.yaml routing looked like this:
- url: "example2.com/*"
service: my-second-website
None of the options we explored provided a scalable or viable solution. Any help or advice will be highly appreciated.

Answer 1

What you need is one App Engine instance with multiple services (one for each website) and multiple versions in each service (if needed).
e.g:
App Engine instance
├── website01-service
│   ├── website01-version01
│   ├── website01-version02
│   └── website01-version03
│
└── website02-service
├── website02-version01
├── website02-version02
└── website02-version03
This is an example setup from Quickstart for Python 3 in the App Engine Standard Environment documentation.
Download the files from git repository as stated in Download the Hello World app section.
Copy the hello_world sample files in two different directories. e.g. website01 and website02.
You should have something like this:
├── website01
│   ├── app.yaml
│   ├── main.py
│   ├── main_test.py
│   └── requirements.txt
└── website02
├── app.yaml
├── main.py
├── main_test.py
└── requirements.txt
In website01/app.yaml add service: website01 and in website02/app.yaml add service: website02. This will deploy each app in different App Engine service.
In website01/main.py change return 'First website!' and in website02/main.py change return 'Second website!' (This is just to confirm after deployment that 2 different websites are running).
In the /website01 directory execute $ gcloud app deploy --version website01-version01 and in /website02 directory execute $ gcloud app deploy --version website02-version01
After a successful deployment, you should see 2 different versions running in Google Cloud Console > App Engine > Services page.
When clicking on both links new tabs will open and you will see your two different websites running in the same App Engine instance with two different links. The links should appear as following:
website01 -> https://website01-dot-[PROJECT_ID].appspot.com/
website02 -> https://website02-dot-[PROJECT_ID].appspot.com/

Answer 2

Have you tried requesting that your project limit be increased? I think that's the only good way to make this work.
If you attempt to exceed your project limit, the console will prompt you to fill out a request form. This happens when you try to create a project but you have already reached your quota. The form will require you to specify the number of additional projects you need, along with their corresponding email accounts, billing accounts, and intended uses.
https://support.google.com/cloud/answer/6330231?hl=en
You could do this with a single project & single service/app.yaml, if your ok with the url for each website being something like :
www.website1.com/website1/
www.website2.com/website2/
www.website3.com/website3/
etc
Then you could use the handlers in app.yaml to do the routing (along with some light server code to redirect if someone tries to visit www.website1.com/website2/). The biggest issue with doing it this way is every time you'd deploy you would be deploying all 100 of your sites.