What does 'curl http://localhost:8080/api/v1/namespaces/default/pods/${POD_NAME}' do?

That particular command is used to ask the Kubernetes API for the configuration and status details of a specific Pod in JSON format.

Here is the breakdown of what happens when you run it:

1. http://localhost:8080: This targets the kubectl proxy you started. The proxy handles the authentication and security, talking to the "brain" of Kubernetes (the API Server) for you.
2. /api/v1/namespaces/default/pods/: This is the official "address" or path in the Kubernetes API where information about Pods is stored.
3. ${POD_NAME}: This is the specific name of your web-app Pod (e.g., web-app-7c8cbd776f-7c9jl).

What is the result?

Instead of seeing a website, you will see a large block of JSON text. This text contains everything Kubernetes knows about that Pod, including:

• Its current IP address within the cluster.
• Which node it is running on.
• Its status (Running, Pending, etc.).
• The container image it is using.

How is it different from the command with /proxy/?

It is easy to mix these two up, so here is the difference:

• Command WITH /proxy/ at the end: Connects through the API to the NGINX web server inside the pod. You use this to see your website (the HTML).
• Command WITHOUT /proxy/ at the end: Connects to the Kubernetes API itself. You use this to see the metadata and status of the Pod (the JSON).

In short: Use it when you want to "inspect" the Pod's settings rather than "visit" the Pod's website!