hostpathctl

#!/usr/bin/env bash

# Kubernetes hostpath provisioner controller
#
# Copyright 2020 Damien Abos All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

set -o errexit -o pipefail -o noclobber -o nounset

DIRNAME=$(dirname $0)

usage() {
    echo "$(basename $0) controls hostpath storage provisioners."
    echo ""
    echo "Usage: $(basename $0) <command> [options] <storage>"
    echo ""
    echo "Available Commands:"
    echo "  create  Create a storageclass and its provisioner"
    echo "  delete  Delete a storageclass and its provisioner"
    echo ""
    echo "Options:"
    echo "    -a, --account=<storage>-account   indicate the security account allowed to create persistent volumes"
    echo "    -h, --help                        print this help message"
    echo "    -i, --image                       indicate the pod provider image"
    echo "    -n, --namespace=default           indicate the target namespace"
    echo "    -p, --path=/tmp/<storage>         indicate the path where persistent volumes will be provisioned on cluster node. It must already exists."
    echo "    -s, --service=<storage>-provider  indicate the pod provider name"
    echo "    --default                         annotate the StorageClass as default"
    echo "    --dry-run='none'                  must be \"none\", \"server\", or \"client\"."
    echo ""
    echo "  # create the hostpath storageclass with its provisioner"
    echo "  $(basename $0) create hostpath -n kube-system"
    echo ""
    echo "  # delete the hostpath storageclass with its provisioner"
    echo "  $(basename $0) delete hostpath -n kube-system"
}

create() {
    envsubst "${SUBSTFMT}" < ${DIRNAME}/rbac.yaml | kubectl apply ${DRYRUN} -f -
    export ACCOUNT_TOKEN=$ACCOUNT_NAME-XXXX
    if [ -z "${DRYRUN}" ]; then
        export ACCOUNT_TOKEN=$(kubectl get serviceaccount ${ACCOUNT_NAME} -n ${NAMESPACE} -o json | jq ".secrets[0].name")
    fi
    envsubst "${SUBSTFMT}" < ${DIRNAME}/storageclass.yaml | kubectl apply ${DRYRUN} -f -
    envsubst "${SUBSTFMT}" < ${DIRNAME}/storage-provisioner.yaml | kubectl apply ${DRYRUN} -f -
    echo "INFO: the path \"${STORAGE_PATH}\" must exists on cluster nodes."
}

delete() {
    envsubst "${SUBSTFMT}" < ${DIRNAME}/storage-provisioner.yaml | kubectl delete ${DRYRUN} -f -
    export ACCOUNT_TOKEN=$ACCOUNT_NAME-XXXX
    if [ -z "${DRYRUN}" ]; then
        export ACCOUNT_TOKEN=$(kubectl get serviceaccount ${ACCOUNT_NAME} -n ${NAMESPACE} -o json | jq ".secrets[0].name")
    fi
    envsubst  "${SUBSTFMT}" < ${DIRNAME}/storageclass.yaml | kubectl delete ${DRYRUN} -f -
    envsubst  "${SUBSTFMT}" < ${DIRNAME}/rbac.yaml | kubectl delete ${DRYRUN} -f -
    echo "INFO: the path \"${STORAGE_PATH}\" shall be cleanned manually on cluster nodes."
}

check-dependencies() {
    dependencyerror=0
    if ! command -v kubectl > /dev/null ; then
        echo "kubectl is missing. Please install and configure kubectl."
        dependencyerror=1
    elif ! kubectl version > /dev/null ; then
        echo "kubectl is not properly configured"
        dependencyerror=2
    fi

    if ! command -v jq > /dev/null ; then
        echo "jq is misssing. Please install kubectl."
        dependencyerror=1
    fi

    if [ ! $dependencyerror = 0 ] ; then
        exit "${dependencyerror}"
    fi
}

check-dependencies

POSITIONAL=()
while [[ $# -gt 0 ]]
do
key="$1"

case $key in
    -n=*|--namespace=*)
    STORAGE_NAMESPACE="${key#*=}"
    shift
    ;;
    -n|--namespace)
    STORAGE_NAMESPACE="$2"
    shift
    shift
    ;;
    -a=*|--account=*)
    STORAGE_ACCOUNT_NAME="${key#*=}"
    shift
    ;;
    -a|--account)
    STORAGE_ACCOUNT_NAME="$2"
    shift
    shift
    ;;
    -s=*|--service=*)
    STORAGE_PROVISIONER_NAME="${key#*=}"
    shift
    ;;
    -s|--service)
    STORAGE_PROVISIONER_NAME="$2"
    shift
    shift
    ;;
    -p=*|--path=*)
    STORAGE_PROVISIONER_PATH="${key#*=}"
    shift
    ;;
    -p|--path)
    STORAGE_PROVISIONER_PATH="$2"
    shift
    shift
    ;;
    -i=*|--image=*)
    STORAGE_PROVISIONER_IMAGE="${key#*=}"
    shift
    ;;
    -i|--image)
    STORAGE_PROVISIONER_IMAGE="$2"
    shift
    shift
    ;;
    --default=*)
    STORAGE_IS_DEFAULT="${key#*=}"
    shift
    ;;
    --default)
    STORAGE_IS_DEFAULT=true
    shift
    ;;
    --dry-run=*)
    DRYRUN=$key
    shift
    ;;
    --dry-run)
    DRYRUN="--dry-run=client"
    shift
    ;;
    -h|--help)
    usage
    exit
    ;;
    *)    # unknown option
    POSITIONAL+=("$1") # save it in an array for later
    shift # past argument
    ;;
esac
done
set -- "${POSITIONAL[@]}" # restore positional parameters

if [[ $# -ne 2 ]]; then
    usage
    exit 4
fi

STORAGE_NAME=$2
NAMESPACE=${STORAGE_NAMESPACE:-default}
ACCOUNT_NAME=${STORAGE_ACCOUNT_NAME:-${STORAGE_NAME}-account}
PROVISIONER_NAME=${STORAGE_PROVISIONER_NAME:-${STORAGE_NAME}-provisioner}
PROVISIONER_IMAGE=${STORAGE_PROVISIONER_IMAGE:-"gcr.io/k8s-minikube/storage-provisioner:v3"}
STORAGE_PATH=${STORAGE_PROVISIONER_PATH:-/tmp/${STORAGE_NAME}}
STORAGE_IS_DEFAULT=${STORAGE_IS_DEFAULT:-false}
DRYRUN=${DRYRUN:-}

export STORAGE_NAME NAMESPACE ACCOUNT_NAME PROVISIONER_NAME PROVISIONER_IMAGE STORAGE_PATH STORAGE_IS_DEFAULT
SUBSTFMT='${STORAGE_NAME} ${NAMESPACE} ${ACCOUNT_NAME} ${PROVISIONER_NAME} ${PROVISIONER_IMAGE} ${STORAGE_PATH} ${STORAGE_IS_DEFAULT} ${ACCOUNT_TOKEN}'

case $1 in
    create)
    create
    ;;
    delete)
    delete
    ;;
    *)
    usage
    exit 4
esac