Kubernetes Crashloopbackoff

Ever had one of those days when everything seems fine, but there's that one irritating pod that just won't stay up?

The most common Kubernetes issue that can really test your patience: the CrashLoopBackOff.

What is it?

Simply put, CrashLoopBackOff is a status message indicating that a pod is failing to start repeatedly. It's Kubernetes' way of telling you, "Hey, something's wrong, and I'm giving it a break before I try again."

What factors cause it?

A variety of issues can trigger a CrashLoopBackOff, such as:

• Application bugs, like unhandled exceptions or critical logic failures, prevent proper startup.

  
  

• Misconfigured volume mounts result in the application not finding necessary files or directories.

  
  

• Incorrect environment variables that lead to startup failures, such as specifying a wrong API URL.

  
  

• Dependencies that are unavailable due to network issues or incorrect DNS settings can cause crashes.

  
  

• Resource constraints, where insufficient CPU or memory allocation hinders the pod's ability to start.

  
  

• Missing config maps or secrets can prevent the application from accessing required configuration or credentials.

Environment:
  API_URL: http://wrong-api-url

The API_URL is set incorrectly, causing the application to fail at startup.

How to detect it?

You'll notice the CrashLoopBackOff pod status:

2. Describe the pod to get more details:

3. Check the logs for specific errors:

kubectl logs techops-app -n production

techops-app /start.sh: 42:

Connection to http://wrong-api-url failed: Host not found

now you see, the root cause is ‘incorrect API URL’

How to rollout the fix ?

Set the environment variable to point to the correct API URL:

2. Redeploy the application:

   
   
3. 

And the pod should be up and running !