Linux interview Questions :

Kubernestes inteview questions for experienced:
 🔥 Kubernetes Interview Questions with Commands 1. How do you check all resources in a cluster? kubectl get all 👉 Namespace specific: kubectl get all -n dev 2. How do you create a resource? kubectl apply -f deployment.yaml 3. How do you check pod details? kubectl describe pod pod-name 4. How do you check pod logs? kubectl logs pod-name 👉 Multi-container pod: kubectl logs pod-name -c container-name 5. How do you exec into a pod? kubectl exec -it pod-name -- /bin/bash 6. How do you check nodes? kubectl get nodes kubectl describe node node-name 7. How do you scale a deployment? kubectl scale deployment app-name --replicas=5 8. How do you check deployment status? kubectl get deployments kubectl describe deployment app-name 9. How do you check rollout status? kubectl rollout status deployment app-name 10. How do you rollback deployment? kubectl rollout undo deployment app-name 11. How do you check services? kubectl get svc kubectl describe svc service-name 12. How do you check endpoints? kubectl get endpoints 13. How do you check events (very important for debugging)? kubectl get events 14. Pod stuck in Pending – what commands? kubectl describe pod pod-name kubectl get nodes kubectl describe node node-name 15. Pod in CrashLoopBackOff – what commands? kubectl logs pod-name kubectl describe pod pod-name 16. ImagePullBackOff issue – commands? kubectl describe pod pod-name kubectl get events 17. How do you check resource usage? kubectl top pod kubectl top node 18. How do you work with namespaces? kubectl get ns kubectl create ns dev kubectl get pods -n dev 19. How do you apply autoscaling (HPA)? kubectl autoscale deployment app-name --cpu-percent=50 --min=1 --max=10 20. How do you check Persistent Volumes? kubectl get pv kubectl get pvc kubectl describe pvc pvc-name 21. How do you cordon and drain a node? kubectl cordon node-name kubectl drain node-name --ignore-daemonsets 22. How do you delete a resource? kubectl delete -f deployment.yaml 23. How do you edit a running resource? kubectl edit deployment app-name 24. How do you port-forward to a pod? kubectl port-forward pod-name 8080:80 25. How do you check cluster info? kubectl cluster-info 💥 Real-Time Scenario Commands (Must Remember) 👉 App not accessible kubectl get svc kubectl get endpoints kubectl describe svc service-name 👉 Pod not scheduling kubectl describe pod pod-name kubectl get nodes kubectl describe node node-name 👉 High CPU issue kubectl top pod kubectl describe pod pod-name 👉 Deployment mismatch (desired vs running) kubectl get deployment kubectl describe deployment app-name kubectl get pods ============================================================ Senior DevOps engineer from Manish Tiwari: ================================= 1).what is the terraform null and provioidners ? Terraform null: null_resource is a dummy resource that does NOT create infrastructure. 👉 It is used to: * Run provisioners * Trigger scripts * Execute automation tasks ✅ Example resource "null_resource" "example" { provisioner "local-exec" { command = "echo Hello from Terraform" } } 👉 This will: * Not create any server * Only execute the command ================================= Terraform provisioners : What are Terraform Provisioners? Provisioners are used to execute scripts or commands on a resource after it is created (or destroyed). 👉 In simple terms:
Terraform creates infrastructure → Provisioner runs extra setup inside it ✅ Types of Provisioners 1. remote-exec Runs commands inside the server (VM/EC2) resource "aws_instance" "example" { ami = "ami-123456" instance_type = "t2.micro" provisioner "remote-exec" { inline = [ "sudo apt update", "sudo apt install nginx -y" ] ================ Why npm is installed into docker file ? ================= Terraform Interview Questions (5 Years Experience) + Commands 1. How do you initialize Terraform? terraform init 👉 Downloads providers, initializes backend 2. How do you validate your code? terraform validate 3. How do you check execution plan? terraform plan 👉 Save plan: terraform plan -out=tfplan 4. How do you apply changes? terraform apply 👉 With saved plan: terraform apply tfplan 5. How do you destroy infrastructure? terraform destroy 6. How do you format code? terraform fmt 7. How do you manage Terraform state? terraform state list terraform state show aws_instance.example 8. How do you move resources in state? terraform state mv old_resource new_resource 9. How do you remove resource from state? terraform state rm aws_instance.example 10. How do you import existing infrastructure? terraform import aws_instance.example i-123456 11. How do you refresh state? terraform refresh 12. How do you taint a resource? terraform taint aws_instance.example 👉 Untaint: terraform untaint aws_instance.example 13. How do you use workspaces? terraform workspace list terraform workspace new dev terraform workspace select dev 14. How do you debug Terraform? TF_LOG=DEBUG terraform apply 15. How do you pass variables? terraform apply -var="instance_type=t2.micro" 👉 Using file: terraform apply -var-file=dev.tfvars 16. How do you output values? terraform output 17. How do you lock state (important for team)? 👉 Backend config (AWS S3 + DynamoDB) backend "s3" { bucket = "my-tf-state" key = "prod/terraform.tfstate" region = "ap-south-1" dynamodb_table = "tf-lock" } 💥 Real-Time Scenario Questions (Must Answer Like This) 👉 Scenario 1: Resource drift (manual change in AWS) Commands: terraform plan terraform apply 👉 Explanation: * Terraform detects drift * Reconciles with code 👉 Scenario 2: Someone deleted resource manually terraform plan terraform apply 👉 It will recreate resource 👉 Scenario 3: Rename a resource without deleting terraform state mv old_name new_name 👉 Scenario 4: Import existing infra terraform import aws_instance.example i-123456 terraform plan 👉 Scenario 5: Fix corrupted state terraform state list terraform state rm terraform import ... 👉 Scenario 6: Multiple environments terraform workspace new dev terraform workspace new prod 👉 Scenario 7: Apply only specific resource terraform apply -target=aws_instance.example 👉 Scenario 8: Dependency issue 👉 Use: depends_on = [aws_vpc.main] 🔥 Advanced Concepts (They WILL ask) 1. Provisioners & Null Resource 👉 Already covered (say not recommended) 2. Modules module "vpc" { source = "./modules/vpc" } 3. Remote Backend 👉 S3 + DynamoDB (must say in interview) 4. for_each vs count 👉 Prefer for_each 5. Lifecycle block lifecycle { prevent_destroy = true } ==========