Cecil’s Data Science Blog - Troubleshooting Kubernetes Pods on AWS

AWS Access

Ensure that you have command-line access to the AWS console to access your AWS resources. You can use the AWS CLI tool through your terminal to verify this. You can run the command below to confirm if you are correctly connected to your AWS account:

aws sts get-caller-identity

You must also specify the name & region of your EKS cluster:

aws eks --region xx-xxxx-x update-kubeconfig --name xxxxxxxx

For example:

aws eks --region us-east-1 update-kubeconfig --name Rstudio-EKS

It also helps to set your namespace to the default namespace that you will be using:

kubectl config set-context --current --namespace=NAMESPACE

For example:

kubectl config set-context --current --namespace=rstudio

Troubleshooting Launched Pods

let’s check to see if we can access the Kubernetes API by launching a Kubernetes pod from our local server to our Kubernetes cluster. You can run the command below to see previously launched pods:

kubectl get pods

If you have launched pods that you are having issues connecting to, you can run the command below for a more detailed description of which stage the pod is in, as well as any errors that may be associated with its launch:

kubectl describe pod <podname>

Where is the name of your Kubernetes pods, obtained by running kubectl get pods. For example:

kubectl describe pod testpod

Launching a test pod

You can launch a test pod to help narrow down connection issues when a pod is created. This will confirm that our localhost can launch pods into our Kubernetes cluster. The easiest way to do so, is to use kubectl to create a pod. Let’s create one called nginx:

kubectl run nginx --image=nginx

Alternatively, you can create a file containing the yaml that you would like to create your pod with. You can create this file by running the below:

sudo touch pod.yaml

The contents of this file will contain the yaml configuration that you will use to launch the test pod. I’ve attached a sample configuration here:

apiVersion: v1
kind: Pod
metadata:
  name: nginx
  labels:
    app: testing
spec:
  containers:
  - image: nginx:latest
    command:
      - "sleep"
      - "604800"
    imagePullPolicy: IfNotPresent
    name: nginx
  restartPolicy: Always

Specification	Descriptor
apiVersion	The version of the Kubernetes API to use
kind	The type of object you wish to create
metadata	The type of data that helps uniquely identify the object
spec	The specification of how you want the pod configured

Save the file, and then apply the default configuration to use the yaml file that you created:

kubectl apply -f pod.yaml

When running this command, you should see confirmation that the pod has been launched:

cecil@localhost:~$ kubectl apply -f pod.yaml
pod/nginx created

Once the pod has been created, you can SSH into the running pod by using the command below:

kubectl exec -it nginx -- /bin/bash