Get kubelet logs from Azure Kubernetes Service (AKS) cluster nodes

03/05/2019
2 minutes to read

As part of operating an AKS cluster, you may need to review logs to troubleshoot a problem. Built-in to the Azure portal is the ability to view logs for the AKS master components or containers in an AKS cluster. Occasionally, you may need to get kubelet logs from an AKS node for troubleshooting purposes.

This article shows you how you can use journalctl to view the kubelet logs on an AKS node.

Before you begin

This article assumes that you have an existing AKS cluster. If you need an AKS cluster, see the AKS quickstart using the Azure CLI or using the Azure portal.

Create an SSH connection

First, create an SSH connection with the node on which you need to view kubelet logs. This operation is detailed in the SSH into Azure Kubernetes Service (AKS) cluster nodes document.

Get kubelet logs

Once you have connected to the node via kubectl debug, run the following command to pull the kubelet logs:

chroot /host
journalctl -u kubelet -o cat

Note

You don't need to use sudo journalctl since you are already root on the node.

Note

For Windows nodes, the log data is in C:\k and can be viewed using the more command:

more C:\k\kubelet.log

The following sample output shows the kubelet log data:

I0508 12:26:17.905042    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:26:27.943494    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:26:28.920125    8672 server.go:796] GET /stats/summary: (10.370874ms) 200 [[Ruby] 10.244.0.2:52292]
I0508 12:26:37.964650    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:26:47.996449    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:26:58.019746    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:27:05.107680    8672 server.go:796] GET /stats/summary/: (24.853838ms) 200 [[Go-http-client/1.1] 10.244.0.3:44660]
I0508 12:27:08.041736    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:27:18.068505    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:27:28.094889    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:27:38.121346    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:27:44.015205    8672 server.go:796] GET /stats/summary: (30.236824ms) 200 [[Ruby] 10.244.0.2:52588]
I0508 12:27:48.145640    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:27:58.178534    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:28:05.040375    8672 server.go:796] GET /stats/summary/: (27.78503ms) 200 [[Go-http-client/1.1] 10.244.0.3:44660]
I0508 12:28:08.214158    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:28:18.242160    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:28:28.274408    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:28:38.296074    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:28:48.321952    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"
I0508 12:28:58.344656    8672 kubelet_node_status.go:497] Using Node Hostname from cloudprovider: "aks-agentpool-11482510-0"

Next steps

If you need additional troubleshooting information from the Kubernetes master, see view Kubernetes master node logs in AKS.