This application attempts to modelize a cat café, with cafés (called "bars" here), cats, and customers.
This application attempts to modelize a cat café, with cafés (called "bars" here), cats, and customers.
---
### REST API
### REST API
Those three entities can be persisted via a REST API. They can also be updated, queried, and removed.
Those three entities can be persisted via a REST API. They can also be updated, queried, and removed.
We used an ASP .NET Web API, with a Swagger configuration to visualize the interface.
We used an ASP .NET Web API, with a Swagger configuration to visualize the interface.
---
### WebSocket
### WebSocket
A WebSocket was set up to notify clients (who subscribe to it) whenever a Cat is `POST`ed.
A WebSocket was set up to notify clients (who subscribe to it) whenever a Cat is `POST`ed.
@ -40,6 +44,7 @@ new WebSocket("wss://localhost:5003/gateway/ws").onmessage = function (event) {
- `"entity-created"` is a hard-coded event ID and should not be changed.
- `"entity-created"` is a hard-coded event ID and should not be changed.
- you are free to change the content of the `Alert` itself, of course
- you are free to change the content of the `Alert` itself, of course
---
### API type choices
### API type choices
#### REST API
#### REST API
@ -61,8 +66,11 @@ Since the connection is opened once and closed once, we avoid any performance lo
and closing a connection for each request-response cycle. Similarly, a server that uses a websocket
and closing a connection for each request-response cycle. Similarly, a server that uses a websocket
can reduce its load, because it is now pushing updates directly instead of being polled regularly by many clients.
can reduce its load, because it is now pushing updates directly instead of being polled regularly by many clients.
---
### API Gateway
### API Gateway
#### How to launch both projects
An [Ocelot](https://ocelot.readthedocs.io/en/latest/) API Gateway manages the whole system.
An [Ocelot](https://ocelot.readthedocs.io/en/latest/) API Gateway manages the whole system.
It can be started using Visual Studio if you first right-click the cat-cafe.sln Solution, and go to Properties.
It can be started using Visual Studio if you first right-click the cat-cafe.sln Solution, and go to Properties.
@ -155,6 +163,19 @@ The gateway uses rate limiting to make sure that clients cannot send an all-incl
}
}
} ...
} ...
```
```
---
## Testing the app
0. Prepare to use Postman
1. Start both the `cat_cafe` and `ApiGateway` projects (you may refer to [this procedure](#how-to-launch-both-projects)). Two browser windows will open, which you will not need to use much.
2. Use whichever browser window to open a WebSocket, so that you will get notifications (you may refer to [that procedure](#websocket))
3. In Postman, inside a workspace, click the `Import` button in the top left corner. Then click `Choose files` and find the collection to import in `docs/Cat Café.postman_collection.json`, in this repo. Follow the procedure to save it.
4. Keep an eye on the browser window you used to open a WebSocket, and execute the requests in this imported collection. When using `POST`, you should get an alert in the browser window.
Notice that the REST API and the WebSocket are accessed through our API Gateway.
In a real-life scenario, we could use IP-blocking or firewalls to ensure that port 7229 can only be accessed by the app itself and the gateway.
