Script to automate mongodb rpm updates steps on ReplicaSet nodes installed on EC2 instances with CentOS7

mongodb_update.sh

#!/usr/bin/bash -e

# This script will be use to automate the mongodb rpm updates steps on ReplicaSet nodes installed on EC2 instances with CentOS7

mongo_connect() {
    mongo --quiet ${MONGO_DB} -u ${MONGO_USER} -p ${MONGO_PASS}
}

usage() {
    cat << EOF

usage:
    $0 <mongo_db> <mongo_user> <mongo_pass> <current_version> <new_version>
EOF
    exit 1
}

# Main

LOCAL_IP=$(curl --silent http://169.254.169.254/latest/meta-data/local-ipv4)

MONGO_DB=$1
MONGO_USER=$2
MONGO_PASS=$3
CURRENT_VERSION=$4
NEW_VERSION=$5

# Testing arguments

test $# -eq 5 || usage

case ${CURRENT_VERSION} in
    2.6|3.0|3.2) ;;
    *) usage;;
esac

case ${NEW_VERSION} in
    3.0|3.2|3.4) ;;
    *) usage
esac

echo -e "\n--- 1. Changing mongodb repo\n"

cat << EOF | sudo tee /etc/yum.repos.d/mongo.repo
[mongodb-org-${NEW_VERSION}]
name=MongoDB Repository ${NEW_VERSION}
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/${NEW_VERSION}/x86_64/
gpgcheck=0
enabled=1
EOF

echo -e "\n--- 2. Replica set status\n"

echo "rs.status()" | mongo ${MONGO_DB} -u ${MONGO_USER} -p ${MONGO_PASS}

echo -e "\n--- 3. Checking that the node is a secondary\n"

IS_PRIMARY=$(echo "rs.status().members.filter(function(rsStatus){return rsStatus.name === \"${LOCAL_IP}:27017\";})[0].stateStr" | mongo_connect)

if [ ${IS_PRIMARY} == "PRIMARY" ]; then
    echo -e "\n\nERROR: this node is PRIMARY\nYou need to run the MongoDB upgrade on a SECONDARY node...\n\n"
    exit 2
fi

echo -e "\n--- 4. Stopping mongodb\n"

sudo systemctl stop mongod

echo -e "\n--- 5. Updating mongodb rpms\n"

sudo yum -y update mongodb-org-server.x86_64 mongodb-org-shell.x86_64 mongodb-org-tools.x86_64

echo -e "\n--- 6. Reloading mongodb service configuration\n"

sudo systemctl daemon-reload

echo -e "\n--- 7. Starting mongodb\n"

sudo systemctl start mongod

echo -e "\n--- 8. Checking mongodb version\n"

sudo grep "db version" /var/log/mongodb/mongod.log

echo -e "\n---9. Checking replica set status (stateStr need to be "SECONDARY")\n"

echo "rs.status().members.filter(function(rsStatus){return rsStatus.name === \"${LOCAL_IP}:27017\";})[0]" | mongo_connect