To operate and maintain TKG clusters, configure a default text editor for kubectl.

Using the kubectl edit command

After you provision a TKG cluster, you operate and maintain it. Typical tasks include scaling cluster nodes and updating the TKR version. To perform such tasks you update the cluster manifest using the kubectl edit command.

The command kubectl edit CLUSTER-KIND/CLUSTER-NAME opens the cluster manifest in the text editor defined by your KUBE_EDITOR or EDITOR environment variable. When you save the manifest changes, kubectl reports that the edits were successfully recorded, and the cluster is updated with the changes.

For example: 
kubectl edit tanzukubernetescluster/tkg-cluster-1
tanzukubernetescluster.run.tanzu.vmware.com/tkg-cluster-1 edited
To cancel changes, close the editor without saving. 
kubectl edit tanzukubernetescluster/tkg-cluster-1
Edit cancelled, no changes made.

Configuring kubectl edit

To use the kubectl edit command, on Linux the EDITOR environment variable is set. Otherwise, create a KUBE_EDITOR environment variable and specify your preferred text editor as the variable value. Append the watch flag ( -w) so that kubectl knows when you have committed (saved) your changes.

Refer to the specific instructions for your operating system.

Linux

To configure kubectl edit on Linux (Ubuntu, for example), the default command-line EDITOR is Vim. If this case, no further action is needed to use the kubectl edit command.

If you want to use a different text editor, create an environment variable named KUBE_EDITOR with the value set to the path of your preferred text editor.

Mac OS

To configure kubectl edit on Mac OS, create an environment variable named KUBE_EDITOR with the value set to the path of your preferred text editor. Append the wait flag ( --wait, or the shortcut -w) to the value so that the editor knows when you have committed (saved) your changes.

For example, the following addition to the .bash_profile sets Sublime as the default text editor for kubectl and includes the wait flag so the editor knows when you have saved any changes. 
export KUBE_EDITOR="/Applications/Sublime.app/Contents/SharedSupport/bin/subl -w"
Windows

To configure kubectl edit on Windows, create a system environment variable named KUBE_EDITOR with the value set to the path of your preferred text editor. Append the watch flag ( -w) to the value.

For example, the following environment variable sets Visual Studio Code as the default text editor for kubectl and includes the watch flag so that Kubernetes knows when you save your changes: 
KUBE_EDITOR=code -w

To configure Sublime as the kubectl editor on Windows, append the Sublime program directory to the sytem path and create a system variable for the Sublime executable. For example:

Sytem PATH append: 
C:\Program Files\Sublime Text 3\
System variable name and value: 
KUBE_EDITOR=sublime_text.exe -w