Install kubectl
Install the Kubernetes client kubectl
Download the kubectl client
After installing the Kubernetes cluster, obtain a kubectl command line tool following the instructions from the kubectl documentation.
Get KUBECONFIG credentials file
After the kubectl installation get KUBECONFIG file:
mkdir $HOME/.kube
scp root@cp1:/etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config
Check the connection to Kubernetes cluster:
kubectl cluster-info
Expected output:
Kubernetes control plane is running at https://cp1:6443
CoreDNS is running at https://cp1:6443/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy
To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
Alternative ways to provide KUBECONFIG for kubectl:
export KUBECONFIG=$HOME/.kube/config
kubectl cluster-info
or
kubectl --kubeconfig=$HOME/.kube/config cluster-info
Configure kubectl client
Configure Bash autocompletion for kubectl:
kubectl completion bash
echo "source <(kubectl completion bash)" >> ~/.bashrc
source <(kubectl completion bash)
Configure the vim text editor
Next, let's configure the text editor that you will use for editing Kubernetes yaml manifests.
The vim text editor is a minimalist text editor that is often available even in bare-bones deployments, which is why we recommend it. However, it is often considered complicated and non-intuitive for developers fairly new to the command line. As an alternative to vim, you can consider the GNU nano text editor, which is described in the next section.
If you have chosen to stick with vim, create a Vim custom configuration file:
" Sets tabstop to 2 for working with YAML
set ts=2
" Sets softtabstop makes spaces feel like tabs
set sts=2
" Sets the shift width to 2, making shift operations (<< or >>)
set sw=2
" Expands new tabs to spaces
set expandtab
" Convert all existing tabs to spaces
retab
" Enable syntax highlighting
syntax on
" For certain filetypes, enable automatic indenting
filetype indent plugin on
" Show column and line number
set ruler
set number
Configure the nano text editor
As an alternative to vim, the GNU nano text editor is a lightweight and versatile terminal-based text editor.
In order to use nano to edit Kubernetes yaml manifest, we need to edit the configuration file, located at $HOME/.nanorc:
# Sets tabstop to 2 for working with YAML
set tabsize 2
# Sets tabs to spaces
set tabstospaces
# Turn on line numbers for ease of reference
set linenumbers
This can also be done automatically using the pipe and tee operators in bash, by running the follwing commands:
echo "set tabsize 2" | tee -a ~/.nanorc
echo "set tabstospaces" | tee -a ~/.nanorc
echo "set linenumbers" | tee -a ~/.nanorc
Adding syntax highlighting for YAML-files
Additionally, syntax highlighting for yaml files can be useful. To achieve this, we first need a .nanorc file to instruct nano on how to handle yaml manifests.
Create a file in $HOME/.nano/ named yaml.nanorc and paste the following:
syntax "YUM" "\.repo$|yum.*\.conf$"
color cyan "^[[:space:]]*[^=]*="
color brightmagenta "^[[:space:]]*\[.*\]$"
color brightyellow "\$(releasever|arch|basearch|uuid|YUM[0-9])"
color brightblack "(^|[[:space:]])#([^{].*)?$"
color ,green "[[:space:]]+$"
color ,red " + +| + +"
Then, ensure that the config is included in the $HOME/.nanorc file by adding the following:
include "~/.nano/yaml.nanorc"
or by running the following command in bash:
echo "include '~/.nano/yaml.nanorc'" | tee -a ~/.nanorc
Wohoo! Your nano text editor should now be ready to go!
Check KUBECONFIG configuration
Check the current KUBECONFIG config:
kubectl config view
kubectl config get-clusters
kubectl config get-users
kubectl config get-contexts
kubectl config current-context
kubectl get pods
Set an example cluster adminstrator context:
kubectl config set-context kube-system-admin --cluster=kubernetes --user=kubernetes-admin --namespace=kube-system
kubectl config get-contexts
kubectl config use-context kube-system-admin
kubectl get pods
Switch back to the previous context:
kubectl config use-context kubernetes-admin@kubernetes
kubectl config current-context