How to fix Exit Code 1 in Kubernetes

The logs reveal the actual error:

kubectl logs <pod-name>

For crashed containers, view previous instance logs:

kubectl logs <pod-name> --previous

For multi-container pods:

kubectl logs <pod-name> -c <container-name> --previous

Look for exception stack traces, error messages, or the last operation before termination.

Missing environment variables are a common cause:

kubectl get pod <pod-name> -o jsonpath='{.spec.containers[0].env}' | jq

Check that referenced secrets and configmaps exist:

kubectl get secrets
kubectl get configmaps

Verify secret values are not empty:

kubectl get secret <secret-name> -o jsonpath='{.data}' | jq

Reproduce the issue outside Kubernetes:

docker run -it <image>:<tag>

If it fails locally, the issue is in the image itself. If it works locally, compare environment differences:
- Environment variables
- Volume mounts
- Network access
- Resource limits

Verify the container command is correct:

kubectl get pod <pod-name> -o jsonpath='{.spec.containers[0].command}'
kubectl get pod <pod-name> -o jsonpath='{.spec.containers[0].args}'

Common issues:
- Shell scripts missing shebang line (#!/bin/bash)
- Scripts not marked executable
- Wrong path to entrypoint file

For debugging, override the command temporarily:

command: ["sleep", "infinity"]

Then exec in and run manually to see real-time errors.

If the app connects to databases or APIs on startup:

# Test from a debug pod
kubectl run debug --rm -it --image=busybox -- /bin/sh

# Inside the pod
nslookup <service-name>
nc -zv <host> <port>

Check if services are available and network policies allow access. For databases, verify credentials and connection strings.

Increase log verbosity to capture more details:

env:
  - name: LOG_LEVEL
    value: "debug"
  - name: NODE_DEBUG
    value: "*"  # For Node.js

For applications that exit quickly, add startup logging or a delay:

# In entrypoint script
echo "Starting application..."
echo "Environment: $(env)"
exec ./myapp