Elasticseach upgrade script

es-upgrade.sh

#!/usr/bin/env bash
set -eu

# function: usage
function usage () {
  cat << EOF
  Elasticsearch rolling upgrade tool. Process modeled after the following documentation:
  https://www.elastic.co/guide/en/elasticsearch/reference/current/rolling-upgrades.html

  Usage: $0 -u <username> -p <password> -v <version>

    -u        Elasticsearch api username. (required)
    -p        Elasticsearch api password. (required)
    -v        Elasticsearch package version to upgrade to (ex 6.8.13-1).
                Uses latest available if left undefined.
    -t        Cluster health check.

EOF
}

function health_check () {
    echo "==> Checking Elasticsearch Cluster health";
    sleep ${1:-0}s;
    curl \
        -X GET \
        -u "${username}:${password}" \
        -H 'Content-Type:application/json;charset=UTF-8' \
        "http://${ip}:9200/_cat/health?v=true&pretty";
    # echo "==> Checking Elasticsearch Recovery";
    # curl \
    #     -X GET \
    #     -u "${username}:${password}" \
    #     -H 'Content-Type:application/json;charset=UTF-8' \
    #    "http://${ip}:9200/_cat/recovery?pretty";
}

# default arguement values
username="";
password="";
version="";
test=false;

# arguement handling
while getopts u:p:v:th FLAG; do
  case $FLAG in
    u|username)
      username=${OPTARG};
      ;;
    p|password)
      password=${OPTARG};
      ;;
    v|version)
      version=${OPTARG};
      ;;
    t|test)
      test=true;
      ;;
    *)
      usage
      exit 0;
      ;;
  esac
done
shift $((OPTIND -1))

# test for missing credentials
if [[ -z ${username} ]] || [[ -z ${password} ]]; then
  echo -e "==> ERROR: Missing Elasticsearch API credentials!\n";
  usage;
  exit 1;
fi

# variables
ip=$(hostname -I | xargs);

# health check
if [[ "${test}" == "true" ]]; then
  health_check
  exit 0;
fi

# prepare elasticsearch for shutdown
# disable cluster routing and perform a synced flush
echo "==> Preparing Elasticsearch node for service shutdown: '$(hostname) (${ip})'"
curl \
    -X PUT \
    -u "${username}:${password}" \
    -H 'Content-Type:application/json;charset=UTF-8' \
    "http://${ip}:9200/_cluster/settings" \
    -d '{ "persistent": { "cluster.routing.allocation.enable": "none" } }';
curl \
    -X POST \
    -u "${username}:${password}" \
    -H 'Content-Type:application/json;charset=UTF-8' \
    "http://${ip}:9200/_flush/synced";
echo ""
sleep 30s;

# shutdown elasticsearch
echo "==> Stopping Elasticsearch service"
systemctl stop elasticsearch;

# upgrade elasticsearch
echo "==> Upgrading Elasticsearch"
yum clean all;
if [[ -z ${version} ]]; then
  yum update elasticsearch -y;
else
  yum install elasticsearch-${version}
fi

# update elasticsearch plugins
IFS=$'\n'
export PATH="/usr/share/elasticsearch/bin:${PATH}"
plugins=($(/usr/share/elasticsearch/bin/elasticsearch-plugin list -s))
unset IFS
for plugin in ${plugins[@]}; do
    echo "==> Updating Elasticsearch plugin: '${plugin}'"
    /usr/share/elasticsearch/bin/elasticsearch-plugin remove -s ${plugin};
    /usr/share/elasticsearch/bin/elasticsearch-plugin install -b -s ${plugin};
done

# start elasticsearch
echo "==> Starting Elasticsearch service"
systemctl start elasticsearch;
sleep 30s;

# enable elasticsearch
echo "==> Re-introducing Elasticsearch node back into cluster: '$(hostname) (${ip})'"
curl \
    -X GET \
    -u "${username}:${password}" \
    -H 'Content-Type:application/json;charset=UTF-8' \
    "http://${ip}:9200/_cat/nodes?pretty";
curl \
    -X PUT \
    -u "${username}:${password}" \
    -H 'Content-Type:application/json;charset=UTF-8' \
    "http://${ip}:9200/_cluster/settings" \
    -d '{ "persistent": { "cluster.routing.allocation.enable": "all" } }';
echo ""

# get cluster health
health_check 30