Issue : Failed to pull image : rpc error: code = 2 desc = unknown blob


When you are deploying an image, which is hosted on a private registry, to a kubernetes (k8s) cluster with windows nodes… Then you might get the following error ;

Failed to pull image ““: rpc error: code = 2 desc = unknown blob
Error syncing pod, skipping: failed to “StartContainer” for “private-reg-container” with ErrImagePull: “rpc error: code = 2 desc = unknown blob”



So what did my setup look like?

  • Orchestrator : Kubernetes for Windows (Azure Container Service)
  • Registry : Private (Azure Container Registry)
  • Image : Windows Nano Based


Technical Check

Let’s deploy two pods…

The first I’ll deploy via yaml, which is basically the example from the kubernetes docs on pulling an image from a private repo

Now the second one is an adaptation of the example flow from the Azure Container Service documentation ;

Now let’s see how that one went…

The first one failed, and the second one passed! What was the difference?

 "nodeSelector": {
    "": "windows"

Apparently this one forces the switch to “windows container mode” (or something like that…). As it seems very similar to the following thread



When deploying windows containers to a kubernetes cluster. be sure to the set the “nodeSelector” or you might end up with errors on pulling the image.