<p>I am currently writing an ARM (Azure Resource Manager) template that creates a Kubernetes cluster. Therefore I am using the templates of existing clusters to compare if I am missing anything. This way I discovered that one of my existing Kubernetes clusters (created in the portal) has the linuxProfile property (as shown below) while the other does not. Now I can not seem to figure out for what exactly I need this user. I can create and use a new cluster with or without this property.
Does anyone know when I need this user and if there are any security vulnerabilities if I do not use it (maybe because of missing ssh)?</p>
<p>The <a href="https://learn.microsoft.com/de-de/azure/templates/microsoft.containerservice/managedclusters?tabs=json#containerservicelinuxprofile-object" rel="nofollow noreferrer">documentation</a> does not help with this, as it only says that this is the administrator for Linux VMs. But it does not specify which VMs are meant (maybe the Kubernetes Nodes? Where would I need a user for them)?</p>
<p>The Kubernetes ARM Quickstart <a href="https://learn.microsoft.com/de-de/azure/aks/kubernetes-walkthrough-rm-template" rel="nofollow noreferrer">guide</a> also has this property but does not explain it in more depth.</p>
<pre><code>...
&quot;properties&quot;: {
...
                &quot;linuxProfile&quot;: {
                    &quot;adminUsername&quot;: &quot;azureuser&quot;,
                    &quot;ssh&quot;: {
                        &quot;publicKeys&quot;: [
                            {
                                &quot;keyData&quot;: &quot;ssh key&quot;
                            }
                        ]
                    }
                }
}
...

</code></pre>

Manuel 
<p>Most time, you don't need to add this property. It's used to set the user and the SSH Public Keypair when you want to SSH into the nodes to take a check or do something you want. <a href="https://learn.microsoft.com/en-us/azure/aks/ssh" rel="nofollow noreferrer">Here</a> is an example. At this time, you need to deploy the extension to add the SSH Key. So you don't need to add the property, if you need, deploy the extension, it also works.</p>
