How to Find All Kubernetes Pods on the Same Node from a Pod Using the Official Python Client

How to Find All Kubernetes Pods on the Same Node from a Pod Using the Official Python Client

Kubernetes, the open-source platform for automating deployment, scaling, and management of containerized applications, is a crucial tool for data scientists. Today, we’ll delve into a specific task: finding all Kubernetes Pods on the same node from a Pod using the official Python client.

Prerequisites

Before we begin, ensure you have the following:

1. A Kubernetes cluster up and running.
2. The official Kubernetes Python client installed. You can install it using pip:

pip install kubernetes

3. Access to a Pod within your Kubernetes cluster.

Step 1: Import the Necessary Libraries

First, we need to import the necessary libraries. We’ll need the config and client modules from the kubernetes package.

from kubernetes import config, client

Step 2: Load the Kubernetes Configuration

Next, we load the Kubernetes configuration. If you’re running this script from a Pod within the cluster, use load_incluster_config(). If you’re running it outside the cluster, use load_kube_config().

config.load_incluster_config()

Step 3: Initialize the API Client

Now, we initialize the API client. We’ll use this client to interact with our Kubernetes cluster.

v1 = client.CoreV1Api()

Step 4: Get the Current Pod’s Node Name

To find all Pods on the same node, we first need to know the current Pod’s node name. We can get this information from the Pod’s metadata.

def get_current_pod_node_name(pod_name, namespace):
    pod = v1.read_namespaced_pod(name=pod_name, namespace=namespace)
    return pod.spec.node_name

Step 5: Get All Pods on the Same Node

Finally, we can get all Pods on the same node. We’ll use the list_pod_for_all_namespaces method and filter the Pods based on the node name.

def get_pods_on_same_node(node_name):
    pods = v1.list_pod_for_all_namespaces(watch=False)
    same_node_pods = [pod for pod in pods.items if pod.spec.node_name == node_name]
    return same_node_pods

Putting It All Together

Here’s the complete script:

from kubernetes import config, client

# Load the configuration
config.load_incluster_config()

# Initialize the API client
v1 = client.CoreV1Api()

def get_current_pod_node_name(pod_name, namespace):
    pod = v1.read_namespaced_pod(name=pod_name, namespace=namespace)
    return pod.spec.node_name

def get_pods_on_same_node(node_name):
    pods = v1.list_pod_for_all_namespaces(watch=False)
    same_node_pods = [pod for pod in pods.items if pod.spec.node_name == node_name]
    return same_node_pods

# Get the current Pod's node name
node_name = get_current_pod_node_name("my-pod", "my-namespace")

# Get all Pods on the same node
same_node_pods = get_pods_on_same_node(node_name)

# Print the names of the Pods
for pod in same_node_pods:
    print(pod.metadata.name)

Replace "my-pod" and "my-namespace" with your Pod’s name and namespace.

Conclusion

In this post, we’ve shown you how to find all Kubernetes Pods on the same node from a Pod using the official Python client. This can be useful for understanding the distribution of your workloads and for debugging issues related to specific nodes. Remember to replace the placeholders with your actual Pod’s name and namespace. Happy coding!

Keywords: Kubernetes, Python, Pods, Node, Kubernetes Python Client, Data Science, Kubernetes Cluster, Kubernetes Configuration, API Client, Pod Metadata, Namespace.

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