Enable Auto-Completion Operation for Kubectl in a Linux Bash Shell

In this short article, we will demonstrate how to install kubectl, setup up auto-completion, and set an alias for kubectl in your bash shell.

When using kubectl commands to interact with your Kubernetes cluster (K8S), auto-completion can be very useful to avoid having to reference a cheat sheet constantly!

Setting an alias for kubectl on the command line, (commonly as k ), also helps save a lot of time when managing your cluster, and is also recommended for the CKA administrator exam as it is very time limited.

Install Kubectl on Linux

1. Open your bash shell. Type kubectl. If you see the message ‘kubectl: command not found’, follow these steps to install kubectl. If it is installed, skip to Step 7.

1. Download the latest kubectl release with the command:

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

1. Download the checksum file:

curl -LO "https://dl.k8s.io/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl.sha256"

1. Validate the kubectl binary against the checksum file:

echo "$(cat kubectl.sha256) kubectl" | sha256sum --check

1. Install kubectl:

sudo install -o root -g root -m 0755 kubectl /usr/local/bin/kubectl

1. Type kubectl . You should now see the tool is installed.

Set up Auto-completion

1. Check if bash-completion is already installed:

type _init_completion

If it is already installed, you will see something like the following:

If it is not installed, install using apt or yum, depending on which package manager you are using (usually apt for Ubuntu):

apt-get install bash-completion

or

yum install bash-completion

1. Set the kubectl completion script source for your shell sessions:

For all users on the system:

kubectl completion bash | sudo tee /etc/bash_completion.d/kubectl > /dev/null

1. Reload your bash shell. Type kubectl - followed by pressing tab twice to see the available options and verify auto-complete is working:

Set Up an Alias for Kubectl and Enable for Auto-completion

1. Set an alias for kubectl as k.

echo 'alias k=kubectl' >>~/.bashrc

1. Enable the alias for auto-completion.

echo 'complete -o default -F __start_kubectl k' >>~/.bashrc

1. Reload your bash shell. Type k - followed by pressing tab twice to see the available options and verify auto-complete is working with the alias.

k -