How to fix ProgressDeadlineExceeded in Kubernetes

View the deployment condition with more detail:

kubectl describe deployment <deployment-name> -n <namespace>

Look for:
- Condition section showing ProgressDeadlineExceeded
- Message explaining why it failed
- Replicas showing how many are desired vs. ready

Inspect the pods created by the deployment:

kubectl get pods -n <namespace> -l app=<label>
kubectl describe pod <pod-name> -n <namespace>

Look at:
- Pod phase (Pending, ContainerCreating, Running, Failed)
- Events section (shows image pull errors, probe failures, etc.)
- Container state (Waiting reason, exit code if Terminated)

Check application logs to see why it's not starting:

# View current logs
kubectl logs <pod-name> -n <namespace>

# View previous attempt if pod restarted
kubectl logs <pod-name> --previous -n <namespace>

# Stream logs as they appear
kubectl logs -f <pod-name> -n <namespace>

Common issues: connection timeouts, missing dependencies, config errors.

Test image pull from your machine:

docker pull <image:tag>

# For private registries
echo $PASSWORD | docker login -u $USER --password-stdin <registry>
docker pull <registry>/<image:tag>

If it fails, check:
- Image name and tag spelling
- Registry URL
- Private registry credentials
- Image exists in the registry

If using a private container registry:

kubectl create secret docker-registry regcred \
  --docker-server=<registry> \
  --docker-username=<user> \
  --docker-password=<password> \
  -n <namespace>

Then add to your deployment spec:

spec:
  template:
    spec:
      imagePullSecrets:
      - name: regcred

Verify the readiness probe is configured correctly:

kubectl get pod <pod-name> -n <namespace> -o yaml | grep -A 20 "readinessProbe"

Common issues:
- initialDelaySeconds is too low (app needs more time to start)
- timeoutSeconds is too low
- Probe is checking the wrong endpoint or port
- Application is not responding on the configured path

Increase initialDelaySeconds if app startup is slow:

readinessProbe:
  httpGet:
    path: /health
    port: 8080
  initialDelaySeconds: 30
  periodSeconds: 10
  timeoutSeconds: 5

Check if pods have enough CPU and memory:

kubectl describe pod <pod-name> -n <namespace> | grep -A 5 "Requests"
kubectl describe nodes | grep -B 5 -A 5 "Allocated resources"

If resources are insufficient, either:
- Reduce pod resource requests in the deployment
- Add more nodes to the cluster
- Delete other pods to free resources
- Increase node capacity

If the underlying issue is slow but legitimate startup:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: <deployment-name>
spec:
  progressDeadlineSeconds: 1200  # 20 minutes instead of 10
  template:
    spec:
      containers:
      - name: app
        image: <image:tag>

Apply the change:

kubectl apply -f deployment.yaml

NOTE: Only increase this after fixing the root cause. A high deadline on a broken deployment wastes time.