eks-dns.sh

#!/bin/bash


#found on
# https://stackoverflow.com/questions/57105561/cannot-access-eks-endpoint-when-private-acess-is-enabled-within-my-vpc
# eg: bash ~/.aws/eks-dns.sh bb-dev-eks-BedMAWiB bb-dev-devops
#
clusterName=$1
awsProfile=$2

#
# Get EKS ip addrs
#
ips=`aws ec2 describe-network-interfaces --profile $awsProfile \
--filters Name=description,Values="Amazon EKS $clusterName" \
| grep "PrivateIpAddress\"" | cut -d ":" -f 2 |  sed 's/[*",]//g' | sed 's/^\s*//'| uniq`

echo "#-----------------------------------------------------------------------#"
echo "# EKS Private IP Addresses:                                              "
echo $ips
echo "#-----------------------------------------------------------------------#"
echo ""

#
# Get EKS API endpoint
#
endpoint=`aws eks describe-cluster --profile $awsProfile --name $clusterName \
| grep endpoint\" | cut -d ":" -f 3 | sed 's/[\/,"]//g'`

echo "#-----------------------------------------------------------------------#"
echo "# EKS Private Endpoint                                                   "
echo $endpoint
echo "#-----------------------------------------------------------------------#"
echo ""

IFS=$'\n'
#
# Create backup of /etc/hosts
#
sudo cp /etc/hosts /etc/hosts.backup.$(date +%Y-%m-%d)

#
# Clean old EKS endpoint entries from /etc/hots
#
if grep -q $endpoint /etc/hosts; then
  echo "Removing old EKS private endpoints from /etc/hosts"
  sudo sed -i "/$endpoint/d" /etc/hosts
fi

#
# Update /etc/hosts with EKS entry
#
for item in $ips
do
    echo "Adding EKS Private Endpoint IP Addresses"
    echo "$item $endpoint" | sudo tee -a /etc/hosts
done