Unlocking the Power of Kubernetes: A Guide on How to SSH into a Pod

Kubernetes has revolutionized container orchestration, providing a scalable and efficient platform for managing containerized applications. However, there are times when you need to troubleshoot or debug issues within a specific pod. In such cases, having the ability to SSH into a Kubernetes pod can be invaluable. In this guide, we'll walk you through the process step by step, demystifying the SSH access to Kubernetes pods.

Prerequisites:

Before diving into the SSH magic, make sure you have the following prerequisites in place:

1. Kubectl Installed:
   Ensure that the Kubernetes command-line tool, kubectl, is installed on your local machine. If not, you can download it from the official Kubernetes website.

2. Access to Kubernetes Cluster:
   You should have access to a Kubernetes cluster and the necessary permissions to interact with it using kubectl.

Step 1: Identify the Pod:

The first step is to identify the pod you want to SSH into. You can list all the pods in a namespace using the following command:

kubectl get pods -n <namespace>

Choose the pod you want to access and note its name.

Step 2: Retrieve Pod's Namespace:

To retrieve the namespace of the chosen pod, use the following command:

kubectl get pod <pod-name> -o=jsonpath='{.metadata.namespace}'

Make a note of the namespace for the subsequent steps.

Step 3: Open SSH Session:

Now that you have the pod name and namespace, you can open an SSH session to the pod. Use the following command, replacing <namespace> and <pod-name> with your actual values:

kubectl exec -it <pod-name> -n <namespace> -- /bin/bash

This command opens an interactive shell session (/bin/bash) within the specified pod.

Step 4: Explore the Pod:

Congratulations! You're now inside the pod. You can navigate, inspect files, and execute commands just as if you were working on a regular server.

# Example: List files in the pod's home directory
ls ~

Step 5: Exit the SSH Session:

Once you've completed your tasks inside the pod, you can exit the SSH session by typing:

exit

More Examples:

Example 1: Executing Commands Directly

You can also execute commands directly without entering an interactive shell. For instance:

kubectl exec <pod-name> -n <namespace> -- ls /app

This command lists the contents of the /app directory in the specified pod.

Example 2: Copy Files to/from Pod

Use the kubectl cp command to copy files between your local machine and the pod:

# Copy a local file to the pod
kubectl cp /path/to/local/file.txt <namespace>/<pod-name>:/path/in/pod/file.txt

# Copy a file from the pod to your local machine
kubectl cp <namespace>/<pod-name>:/path/in/pod/file.txt /path/to/local/file.txt