Kubernetes Context Configuration command line utility

kb-config-ctx.sh

#!/bin/bash
############################################################################################
#
#         MIT License
#
#         Copyright (c) 2019 Dilip J. Ramírez (https://github.com/dukuo)
#
#         Permission is hereby granted, free of charge, to any person obtaining a copy
#         of this software and associated documentation files (the "Software"), to deal
#         in the Software without restriction, including without limitation the rights
#         to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#         copies of the Software, and to permit persons to whom the Software is
#         furnished to do so, subject to the following conditions:
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#         The above copyright notice and this permission notice shall be included in all
#         copies or substantial portions of the Software.
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#         THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#         IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#         FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#         AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#         LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#         OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
#         SOFTWARE.
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############################################################################################

# Config cluster config. To use mainly with minikube.
#
# Usage:
# 	kb-set-ctx.sh (-c|--cluster-name) CLUSTER_NAME (-i|--ip) IP_ADDRESS (-p|--port) PORT (-d|--config-dir) CONFIG_DIR


# Default values

SET_CTX=false


# Print command help.
function print_help() {
	echo "

	Kubernetes Context Configuration command utility

	--

	Usage:
		
		kb-config-ctx.sh [(-e|--embed-certs) (-s|--set-context)] (-c|--cluster-name) CLUSTER_NAME (-i|--ip) IP_ADDRESS (-p|--port) PORT (-d|--config-dir) CONFIG_DIR 

		Don't forget to `chmod +x kb-config-ctx.sh` for execution permissions.

	--

	Options:

		Required:

		-i | --ip IP_ADDRESS	:	Set cluster server IP_ADDRESS
		-p | --port PORT	:	Set cluster server PORT
		-c | --cluster-name	:	Set cluster server NAME
		-d | --config-dir	:	Set context CONFIGURATION DIRECTORY

		Optional:

		-e | --embed-certs	:	Embed certificates in kube config
		-s | --set-context	:	Set the configured context to current context

	"
	exit 1
}

# Test an IP_ADDRESS address for validity:
# source: https://www.linuxjournal.com/content/validating-ip-address-bash-script
# Usage:
#      valid_ip IP_ADDRESS
#      if [[ $? -eq 0 ]]; then echo good; else echo bad; fi
#   OR
#      if valid_ip IP_ADDRESS; then echo good; else echo bad; fi
#
function valid_ip()
{
    local  ip=$1
    local  stat=1

    if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
        OIFS=$IFS
        IFS='.'
        ip=($ip)
        IFS=$OIFS
        [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 \
            && ${ip[2]} -le 255 && ${ip[3]} -le 255 ]]
        stat=$?
    fi
    return $stat
}


# Fetch Options (required)
while [ -n "$1" ]; do

	case "$1" in

	-i|--ip)
		if valid_ip $2; then
			IP_ADDRESS="$2";
		else
			echo "Must enter a valid IP ADDRESS";
			exit 1;
		fi
		shift
		;;
	-p|--port)
		if [ ! -z $2 ] && [ $2 -gt 0 ]; then
			PORT="$2"
		else
			echo "Must enter a valid PORT"
			exit 1
		fi
		shift
		;;
	-c|--cluster-name)
		if [ ! -z $2 ]; then
			CLUSTER_NAME=$2
		else
			echo "Must enter CLUSTER NAME."
			exit 1
		fi
		shift
		;;
	-d|--config-dir)
		if [ ! -z $2 ]; then
			CONFIG_DIR=$2
		else
			echo "Enter valid DIRECTORY"
			exit 1
		fi
		shift
		;;
	-h|-help)
		print_help
		shift
		;;
	-e|--embed)
		EMBED_CERTS=true
		shift
		;;
	-s|--set-context)
		SET_CTX=true
		shift
		;;
	""|*)
		echo "Option not recognized. Use -h or --help to get the available options."
		print_help
		shift
		;;
	esac
	shift

done
#}

kube_config() {
	# 1 = CLUSTER_NAME | 2 = IP_ADDRESS | 3 = PORT | 4 = CONF_DIR
	if [ "$EMBED_CERTS" = true ] ; then
		E="--embed-certs"
	else
		E=""
	fi
	SERVER="https://$IP_ADDRESS:$PORT"
	CA="$CONFIG_DIR/$CA_CRT"
	CC="$CONFIG_DIR/$CLIENT_CRT"
	CK="$CONFIG_DIR/$CLIENT_KEY"

	# Run kubectl commands (finally)
	kubectl config set-cluster $CLUSTER_NAME --server=$SERVER --certificate-authority=$CA $E
	kubectl config set-credentials $CLUSTER_NAME --client-certificate=$CC --client-key=$CK $E
	
	if [ "$SET_CTX" = true ] ; then
		kubectl config set-context $CLUSTER_NAME --cluster=$CLUSTER_NAME --user=$CLUSTER_NAME
	fi

	exit 1
}


if [ ! -z $CLUSTER_NAME ] && [ ! -z $IP_ADDRESS ] && [ ! -z $PORT ] && [ ! -z $CONFIG_DIR ]; then
	read -p "Set Certificate Authority Certificate filename (default: ca.crt): " CA_CRT
	read -p "Set Client Certificate filename (default: client.crt)" CLIENT_CRT
	read -p "Set Client Key filename (default: client.key)" CLIENT_KEY
	
	CA_CRT=${CA_CRT:=ca.crt}
	CLIENT_CRT=${CLIENT_CRT:=client.crt}
	CLIENT_KEY=${CLIENT_KEY:=client.key}

	kube_config
else
	echo "Some options are required."
	print_help
fi