🚀 Set Resource Limits in Kubernetes Pods

Resource management is one of the most important aspects of running applications in Kubernetes. By setting CPU and memory requests and limits, you ensure fair resource usage and prevent a single Pod from consuming all node resources.

In this guide, we’ll create an Apache HTTPD Pod with defined CPU and memory requests and limits.

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🧠 Task Overview

We need to create a Kubernetes Pod with the following specifications:

ℹ️ Note: kubectl is already configured to interact with the Kubernetes cluster.

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📌 Why Resource Requests and Limits Matter

• Requests define the minimum resources guaranteed to a Pod

• Limits define the maximum resources a Pod can consume

• Prevents resource starvation

• Improves cluster stability and performance

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🧩 Step 1: Create the Pod YAML File

Create a file named httpd-pod.yaml.

📄 Create the file

vi httpd-pod.yaml

📌 Pod Definition

apiVersion: v1
kind: Pod
metadata:
  name: httpd-pod
spec:
  containers:
  - name: httpd-container
    image: httpd:latest
    resources:
      requests:
        memory: "15Mi"
        cpu: "100m"
      limits:
        memory: "20Mi"
        cpu: "100m"

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🔍 YAML Explanation

resources:
  requests:
    memory: "15Mi"   # Minimum memory guaranteed
    cpu: "100m"      # Minimum CPU guaranteed (0.1 core)
  limits:
    memory: "20Mi"   # Maximum memory allowed
    cpu: "100m"      # Maximum CPU allowed

• Mi = Mebibytes

• 100m CPU = 0.1 CPU core

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🚀 Step 2: Apply the Pod Configuration

Deploy the Pod to the Kubernetes cluster:

kubectl apply -f httpd-pod.yaml

✅ Expected Output

pod/httpd-pod created

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🔎 Step 3: Verify the Pod

Check the Pod status:

kubectl get pod httpd-pod

🟢 Sample Output

NAME        READY   STATUS    RESTARTS   AGE
httpd-pod   1/1     Running   0          20s

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🧾 Step 4: Verify Resource Limits

Describe the Pod and inspect resource limits:

kubectl describe pod httpd-pod | grep -A5 "Limits"

🟢 Sample Output

Limits:
  cpu:     100m
  memory:  20Mi
Requests:
  cpu:     100m
  memory:  15Mi

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🛠️ Common Troubleshooting Tips

❌ Pod stuck in Pending

kubectl describe pod httpd-pod

✔️ Node may not have sufficient resources
✔️ Requests exceed available capacity

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❌ Pod gets OOMKilled

✔️ Increase memory limit
✔️ Optimize application memory usage

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🎯 Conclusion

In this guide, you learned how to:

• Define CPU and memory requests

• Set resource limits for a Kubernetes Pod

• Deploy and verify a resource-constrained Pod

• Inspect Pod resource configurations

Setting resource limits is a best practice in production Kubernetes clusters to ensure reliability and fair scheduling.

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🚀 Next Steps

Here are some excellent follow-up topics:

• Resource Quotas per Namespace

• LimitRange in Kubernetes

• Horizontal Pod Autoscaler (HPA)

• Monitoring resource usage with metrics-server