Prompt Title: Connect FastAPI WebSocket Kubernetes

To expose a WebSocket port in Kubernetes, you can use one of the following methods:

1. NodePort Service: This method exposes the WebSocket port on each node in your Kubernetes cluster. It assigns a static port on each node and forwards traffic to the corresponding service port.

   Here's an example of a NodePort service YAML configuration:

   yamlCopy code
   apiVersion: v1
   kind: Service
   metadata:
     name: websocket-service
   spec:
     type: NodePort
     selector:
       app: your-app-label
     ports:
       - name: websocket
         port: 8080  # The port exposed by the service
         targetPort: 8000  # The port on which your FastAPI server listens
         protocol: TCP
   

   In the example above, the service is named websocket-service, and it forwards traffic to pods with the label app: your-app-label. The WebSocket port exposed by the service is 8080, and the target port should match the port on which your FastAPI server is listening (in this case, 8000).

   After applying this YAML configuration (kubectl apply -f service.yaml), you can access the WebSocket server using any node's IP address and the assigned NodePort, like ws://<node-ip>:<node-port>/ws.

2. LoadBalancer Service: If your Kubernetes cluster supports external load balancers, you can use a LoadBalancer service to expose the WebSocket port. The load balancer distributes incoming traffic across your cluster's nodes.

   Here's an example of a LoadBalancer service YAML configuration:

   yamlCopy code
   apiVersion: v1
   kind: Service
   metadata:
     name: websocket-service
   spec:
     type: LoadBalancer
     selector:
       app: your-app-label
     ports:
       - name: websocket
         port: 8080  # The port exposed by the service
         targetPort: 8000  # The port on which your FastAPI server listens
         protocol: TCP
   

   In this example, the service is named websocket-service, and it forwards traffic to pods with the label app: your-app-label. The WebSocket port exposed by the service is 8080, and the target port should match the port on which your FastAPI server is listening (in this case, 8000).

   After applying this YAML configuration (kubectl apply -f service.yaml), Kubernetes will provision an external load balancer, and you can connect to the WebSocket server using the load balancer's external IP address, like ws://<load-balancer-ip>:8080/ws.

3. Ingress Controller: If your Kubernetes cluster has an Ingress controller set up, you can use an Ingress resource to expose the WebSocket port. Ingress provides an easy way to manage external access to services within your cluster.

   Here's an example of an Ingress YAML configuration:

   yamlCopy code
   apiVersion: networking.k8s.io/v1
   kind: Ingress
   metadata:
     name: websocket-ingress
     annotations:
       kubernetes.io/ingress.class: nginx  # Replace with your Ingress controller class
   spec:
     rules:
       - http:
           paths:
             - path: /ws
               pathType: Prefix
               backend:
                 service:
                   name: websocket-service
                   port:
                     number: 8080  # The port exposed by the service
   

   In the example above, the Ingress is named websocket-ingress, and it directs traffic with the /ws path to the websocket-service. The WebSocket port exposed by the service is 8080.