A Technical I.T./DevOps Blog
Problem scenario
You have some Pods in Kubernetes that you want deleted. What should you do?
Solution
1. Find the names. You can run this to find out: kubectl get pods
2. Run this command, but replace “foobar” with the name of the pod you want deleted: kubectl delete pods foobar
3. That should be it. Run kubectl get pods to verify deletion was successful.
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Problem scenario
You run kubectl get pods and you find many or all are not ready. What should you do?
Solution
Run this command: kubectl describe pods
The resulting output should help you.
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Continue reading “How Do You Troubleshoot Kubernetes when Pods Are Not Ready?”
One or both of the following scenarios applies.
Problem scenario #1
Try to install kubectl, but you get an error message about it being installed.
Problem scenario #2
You run “man kubectl” but you see no man page. You still think kubectl is installed.
What should you do?
Solution
Run this command: kubectl version
The results should give you some clues as to what is wrong.
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Continue reading “How Do You Know if kubectl Is Installed on Your Linux Server?”
Problem scenario
You run this command: sudo kubeadm init
You get this problem: “[ERROR KubeletVersion]: couldn’t get kubelet version: executable file not found in $PATH”
What should you do?
Solution
Install kubelet. See this posting you need assistance. (If it is a Red Hat distribution of Linux, you can try How Do You Install kubectl,
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Problem scenario
Kubernetes can use YAML files for configuration. The book Kubernetes in Action by Luksa refers to these files as manifests (pages 148), YAML manifests (page 155) or “pod manifests” (page 451). The Kubernetes website refers to this YAML file as “the PodSpec” here. Pod templates are defined inside these .yaml files (as a subset of the file itself). How do you use these YAML files?
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Continue reading “How Do You Use a YAML File or a YAML Manifest in Kubernetes?”
Problem scenario
You try to go to the default Kubernetes web UI (the dashboard), but you are being prompted for a username and password.
Solution
From the server with kubectl, run this:
kubectl config view
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Continue reading “How Do You Find the Default Kubernetes Web UI Credentials?”
Question
What is the difference between these three two-word terms “pod label,” “label selector,” and “pod selector”?
Answer
This answer provides details on what these are and provides some information on how they are different.
pod label: It is an inherent attribute of the pod. It can be changed via a command like this: kubectl label pod new-podlabel version=5.5 These statements were based on Assistanz.com.
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Problem Scenario
You have some GKE standard clusters that you want deleted. You try to delete them, but they do not go away. What should you do?
Solution
Root cause: Kubernetes clusters are self-healing. They are acting as they were designed. Once the instance group is deleted, you will be able to delete the instances via the web UI or via Google’s Cloud Shell.
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Continue reading “How Do You Delete VM Instances from GCP That Pertain to GKE?”
Problem scenario
You want to view the website that is powered by Kubernetes. But you do not know which URL to go to. What should you do from the back-end server with kubectl?
Solution
1. Run this: kubectl get services
With the resulting output, find a name that you want the URL for. (Services have names.) Let’s assume the name was “foobar”.
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Continue reading “How Do You Find the URL of Your Kubernetes Cluster?”
Updated 9/20/19
Problem scenario
You run the kubectl command. You receive “Error from server (NotFound): the server could not find the requested resource.” How do you resolve this?
Solution
1.a. Run this command: kubectl version | grep Version
Look at the GitVersion values for the client and server. They should match or nearly match.
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