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

Grein
08/01/2024

When operating an Azure Kubernetes Service (AKS) cluster, you may need to review logs to troubleshoot a problem. Azure portal has a built-in capability that allows you to view logs for AKS main components and cluster containers. Occasionally, you may need to get kubelet logs from AKS nodes for troubleshooting purposes.

This article shows you how you can use journalctl to view kubelet logs on an AKS node. Alternatively, customers can collect kubelet logs using the syslog collection feature in Azure Monitor - Container Insights.

Before you begin

This article assumes you have an existing AKS cluster. If you need an AKS cluster, create one using Azure CLI, Azure PowerShell, or Azure portal.

Using kubectl raw

You can quickly view any node kubelet logs by using the following command:

kubectl get --raw "/api/v1/nodes/nodename/proxy/logs/messages"|grep kubelet

Create an SSH connection

First, you need to create an SSH connection with the node you need to view kubelet logs for. To create this connection, follow the steps in SSH into AKS cluster nodes.

Get kubelet logs

Once you connect to the node using kubectl debug, run the following command to pull the kubelet logs:

chroot /host
journalctl -u kubelet -o cat

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 example output shows 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 more troubleshooting information for the Kubernetes main, see view Kubernetes main node logs in AKS.

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