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<@ULVA73B9P> error returned from the worker: PS ku...
# ask-marvin
a
@Marvin error returned from the worker: PS kubectl logs prefect-worker-59b68cc875-sxwt6 -n demo Defaulted container "prefect-worker" out of: prefect-worker, sync-base-job-template (init) Worker 'KubernetesWorker 9d409b77-dedf-416d-a4e4-754943e3982e' started! 140953.242 | INFO | prefect.flow_runs.worker - Pod event 'Pulling' (3 times) at 2025-03-04 141031+0000 Pulling image "prefect-flow-registry.demo.svc.cluster.local5000/test flowlatest" Failed to pull image "prefect-flow-registry.demo.svc.cluster.local5000/test flowlatest": failed to pull and unpack image "prefect-flow-registry.demo.svc.cluster.local5000/test flowlatest": failed to resolve reference "prefect-flow-registry.demo.svc.cluster.local5000/test flowlatest": failed to do request: Head "https://prefect-flow-registry.demo.svc.cluster.local:5000/v2/test-flow/manifests/latest": dial tcp: lookup prefect-flow-registry.demo.svc.cluster.local: no such host 141053.581 | INFO | prefect.flow_runs.worker - Pod event 'Failed' (3 times) at 2025-03-04 141031+0000 Error: ErrImagePull 141053.581 | INFO | prefect.flow_runs.worker - Pod event 'BackOff' (3 times) at 2025-03-04 141043+0000 Back-off pulling image "prefect-flow-registry.demo.svc.cluster.local5000/test flowlatest" 141053.582 | INFO | prefect.flow_runs.worker - Pod event 'Failed' (3 times) at 2025-03-04 141043+0000 Error: ImagePullBackOff 141053.621 | INFO | prefect.flow_runs.worker - Reported flow run '9a66a015-6778-477c-952a-ff83ba165056' as crashed: Flow run infrastructure exited with non-zero status code -1
m
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Ah, the joys of dealing with Kubernetes and image pulling issues. It seems like your Prefect worker is having trouble pulling the Docker image for your flow. Here's a breakdown of the problem and some steps you might consider: ### Problem Summary - Error: The worker is unable to pull the Docker image 
prefect-flow-registry.demo.svc.cluster.local:5000/test-flow:latest
. - Cause: This is due to a DNS resolution failure (
no such host
) for the registry 
prefect-flow-registry.demo.svc.cluster.local
. ### Possible Causes and Solutions 1. DNS Resolution Issue: - Cause: The Kubernetes cluster cannot resolve the hostname 
prefect-flow-registry.demo.svc.cluster.local
. - Solution: Ensure that the DNS settings in your Kubernetes cluster are correctly configured. You might need to check your cluster's CoreDNS settings or any custom DNS configurations. 2. Registry Configuration: - Cause: The registry might not be correctly set up or accessible from within the cluster. - Solution: Verify that the registry service is running and accessible. You can use 
kubectl get svc -n demo
to check the service status. 3. Network Policies: - Cause: Network policies might be blocking access to the registry. - Solution: Check if there are any network policies in place that might be preventing access to the registry and adjust them accordingly. 4. Image Tagging: - Cause: The image tag 
latest
might not exist or be incorrectly tagged. - Solution: Double-check that the image is correctly tagged and pushed to the registry. 5. Cluster Configuration: - Solution: Ensure that your cluster is configured to allow pulling images from the specified registry. ### Additional Steps - Logs and Events: Use 
kubectl describe pod <pod-name> -n demo
to get more detailed information about the pod events. - Registry Access: Test accessing the registry from within the cluster using a simple pod with debugging tools like 
curl
or 
wget
. If you need further assistance, it would be helpful to know more about your Kubernetes setup and any specific configurations you might have.
a
@Marvin can it be that I am using http and not https for the pulling? Or that the values of the worker is not set up for using docker as a type?
m
Both of your suspicions could indeed be contributing to the issue. Let's break down each possibility: ### Using HTTP Instead of HTTPS - Cause: If your registry is configured to use HTTP instead of HTTPS, but your worker is trying to access it over HTTPS, you'll encounter issues. - Solution: - Ensure that your registry is accessible over HTTP if that's what it's configured for. Check your Docker or Kubernetes configuration to see if there's any enforced HTTPS setting. - If your registry is supposed to use HTTPS, make sure it has a valid SSL certificate and is configured correctly. ### Worker Configuration for Docker - Cause: If the worker's configuration isn't set up to use Docker as the infrastructure type, it might not be pulling the image correctly. - Solution: - Verify the worker's configuration to ensure it's set to use Docker. Check the Prefect configuration for the worker, especially the 
infrastructure
or 
executor
settings. - You may need to specify Docker-specific settings in the worker's configuration, such as image pull secrets if your registry requires authentication. ### Steps to Verify 1. Registry Access: - Test accessing the registry directly using HTTP from within a Kubernetes pod to confirm the protocol in use. 2. Worker Configuration: - Review the worker's configuration settings to ensure Docker is specified as the infrastructure type. You can typically find this in the Prefect deployment YAML or through environment variables. 3. Prefect Settings: - Check the Prefect settings to ensure they're correctly configured for your environment. This includes registry URL, authentication, and Docker settings. If you need more detailed guidance on configuring the worker or accessing the registry, let me know, and I can look up specific documentation or examples for you.
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