devel-worker.sh

#!/usr/bin/env bash



set -o pipefail

set -o nounset

set -o errexit



IFS=$'\n\t'



function print_help {

    echo "usage: $0 [options] devel"

    echo "Bootstraps an instance into an EKS cluster"

    echo ""

    echo "-h,--help print this help"

    echo "--use-max-pods Sets --max-pods for the kubelet when true. (default: true)"

    echo "--b64-cluster-ca The base64 encoded cluster CA content. Only valid when used with --apiserver-endpoint. Bypasses calling \"aws eks describe-cluster\""

    echo "--apiserver-endpoint The EKS cluster API Server endpoint. Only valid when used with --b64-cluster-ca. Bypasses calling \"aws eks describe-cluster\""

    echo "--kubelet-extra-args Extra arguments to add to the kubelet. Useful for adding labels or taints."

}



POSITIONAL=()



while [[ $# -gt 0 ]]; do

    key="$1"

    case $key in

        -h|--help)

            print_help

            exit 1

            ;;

        --use-max-pods)

            USE_MAX_PODS="$2"

            shift

            shift

            ;;

        --b64-cluster-ca)

            B64_CLUSTER_CA=$2

            shift

            shift

            ;;

        --apiserver-endpoint)

            APISERVER_ENDPOINT=$2

            shift

            shift

            ;;

        --kubelet-extra-args)

            KUBELET_EXTRA_ARGS=$2

            shift

            shift

            ;;

        *)    # unknown option

            POSITIONAL+=("$1") # save it in an array for later

            shift # past argument

            ;;

    esac

done



set +u

set -- "${POSITIONAL[@]}" # restore positional parameters

CLUSTER_NAME="$1"

set -u



USE_MAX_PODS="${USE_MAX_PODS:-true}"

B64_CLUSTER_CA="${B64_CLUSTER_CA:-}"

APISERVER_ENDPOINT="${APISERVER_ENDPOINT:-}"

KUBELET_EXTRA_ARGS="${KUBELET_EXTRA_ARGS:-}"



if [ -z "$CLUSTER_NAME" ]; then

    echo "CLUSTER_NAME is not defined"

    exit  1

fi



ZONE=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone)

AWS_DEFAULT_REGION=$(echo $ZONE | awk '{print substr($0, 1, length($0)-1)}')



### kubelet kubeconfig



CA_CERTIFICATE_DIRECTORY=/etc/kubernetes/pki

CA_CERTIFICATE_FILE_PATH=$CA_CERTIFICATE_DIRECTORY/ca.crt

mkdir -p $CA_CERTIFICATE_DIRECTORY

if [[ -z "${B64_CLUSTER_CA}" ]] && [[ -z "${APISERVER_ENDPOINT}" ]]; then

    DESCRIBE_CLUSTER_RESULT="/tmp/describe_cluster_result.txt"

    aws eks describe-cluster \

        --region=${AWS_DEFAULT_REGION} \

        --name=${CLUSTER_NAME} \

        --output=text \

        --query 'cluster.{certificateAuthorityData: certificateAuthority.data, endpoint: endpoint}' > $DESCRIBE_CLUSTER_RESULT

    B64_CLUSTER_CA=$(cat $DESCRIBE_CLUSTER_RESULT | awk '{print $1}')

    APISERVER_ENDPOINT=$(cat $DESCRIBE_CLUSTER_RESULT | awk '{print $2}')

fi



echo $B64_CLUSTER_CA | base64 -d > $CA_CERTIFICATE_FILE_PATH



kubectl config \

    --kubeconfig /var/lib/kubelet/kubeconfig \

    set-cluster \

    kubernetes \

    --certificate-authority=/etc/kubernetes/pki/ca.crt \

    --server=$APISERVER_ENDPOINT

sed -i s,CLUSTER_NAME,$CLUSTER_NAME,g /var/lib/kubelet/kubeconfig



### kubelet.service configuration



INTERNAL_IP=$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)

INSTANCE_TYPE=$(curl -s http://169.254.169.254/latest/meta-data/instance-type)

DNS_CLUSTER_IP=10.100.0.10

if [[ $INTERNAL_IP == 10.* ]] ; then

    DNS_CLUSTER_IP=172.20.0.10;

fi



if [[ "$USE_MAX_PODS" = "true" ]]; then

    MAX_PODS_FILE="/etc/eks/eni-max-pods.txt"

    MAX_PODS=$(grep $INSTANCE_TYPE $MAX_PODS_FILE | awk '{print $2}')

    if [[ -n "$MAX_PODS" ]]; then

        cat <<EOF > /etc/systemd/system/kubelet.service.d/20-max-pods.conf

[Service]

Environment='KUBELET_MAX_PODS=--max-pods=$MAX_PODS'

EOF

    fi

fi



cat <<EOF > /etc/systemd/system/kubelet.service.d/10-kubelet-args.conf

[Service]

Environment='KUBELET_ARGS=--node-ip=$INTERNAL_IP --cluster-dns=$DNS_CLUSTER_IP --pod-infra-container-image=602401143452.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/eks/pause-amd64:3.1'

EOF



if [[ -n "$KUBELET_EXTRA_ARGS" ]]; then

    cat <<EOF > /etc/systemd/system/kubelet.service.d/30-kubelet-extra-args.conf

[Service]

Environment='KUBELET_EXTRA_ARGS=$KUBELET_EXTRA_ARGS'

EOF

fi



systemctl daemon-reload

systemctl enable kubelet

systemctl start kubelet