How read a file from a pod in Azure Kubernetes Service (AKS) in a Pythonic way?

I have a requirement to read a file which is located inside a particular folder in a pod in AKS.

My manual flow would be to:

1. exec into the pod with kubectl.
2. cd to the directory where the file is located.
3. cat the file to see it's contents.

I want to automate all this purely using python. I am able to do it with subprocess but that would work only on a machine which has azure and kubectl setup.

Thus, I am looking for a purely pythonic way of doing this. I have looked into the Kubernetes client for Python but I am not able to find a way to do everything which I listed above.

To read a file which is located inside a particular folder in a pod in AKS via Python script, follow the below steps

Assuming you have a valid aks cluster up and running, deploy a pod with your desired file.

For example -

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
  labels:
    app: my-app
spec:
  containers:
  - name: my-container
    image: busybox
    command: ["/bin/sh", "-c", "echo 'Hello from AKS' > /data/file.txt && sleep 3600"]
    volumeMounts:
    - name: data-volume
      mountPath: "/data"
  volumes:
  - name: data-volume
    emptyDir: {}

kubectl apply -f pod.yaml
kubectl get pods

This one says `Hello from AKS' and it should reflect the same when you read the file from the pod using python.

Install / update the necessary dependencies

pip install kubernetes

Here's the script-

from kubernetes import client, config, stream

def read_file_from_pod(namespace: str, pod_name: str, container_name: str, file_path: str) -> str:
    try:
        config.load_incluster_config()
    except config.config_exception.ConfigException:
        config.load_kube_config()

    api_instance = client.CoreV1Api()
    command = ["cat", file_path]

    try:
        exec_response = stream.stream(
            api_instance.connect_get_namespaced_pod_exec,
            name=pod_name,
            namespace=namespace,
            command=command,
            container=container_name,
            stderr=True,
            stdin=False,
            stdout=True,
            tty=False,
        )
        return exec_response
    except Exception as e:
        return f"Error reading file from pod: {str(e)}"

if __name__ == "__main__":
    namespace = "default"
    pod_name = "my-pod"
    container_name = "my-container"
    file_path = "/data/file.txt"

    file_contents = read_file_from_pod(namespace, pod_name, container_name, file_path)
    print("File Contents:", file_contents)

Save and run the script. Now you can read a file from a pod in AKS in a Pythonic way.