Backup a MongoDB cluster and upload it to S3

backup_mongodb_to_s3.sh

#!/bin/bash
#
# DESCRIPTION:
#   Make a gzipped backup from a MongoDB cluster >=3.2.0,
#   preferrable from a slave, and upload it to the
#   specified S3 bucket.
#
# REQUIREMENTS:
#   sudo apt-get install -y awscli
#   sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4
#   /bin/echo "deb [ arch=amd64 ] https://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/4.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.0.list
#   sudo apt-get update
#   sudo apt-get install -y mongodb-org-tools
#

WORKDIR=$(dirname "$0")
source $WORKDIR/exit_handlers.sh # see https://gist.github.com/jweyrich/a2ad1cbc6d87725f4f99dfea188a7cf0
function array_join { local IFS="$1"; shift; /bin/echo "$*"; }

AWSCLI_PROFILE="backup-mongodb" # CONFIGURATION
REPLICA_SET="rs0" # CONFIGURATION
HOSTS=( \
    "mongo01.example.com:27017" \
    "mongo02.example.com:27017" \
    "mongo03.example.com:27017" \
    "mongo04.example.com:27017" \
    "mongo05.example.com:27017" \
) # CONFIGURATION
HOST_STRING=$(array_join , "${HOSTS[@]}")

# Folder where backup files are temporarily stored
BAK_DEST=/backup # CONFIGURATION

# S3 bucket name where backups will be stored
S3_BUCKET=CHANGE_ME # CONFIGURATION

# Number of days to keep archives
KEEP_DAYS=1 # CONFIGURATION

# Variables
ARCHIVE_DATETIME=$(/bin/date +%F-%H%M)
ARCHIVE_PATH=${BAK_DEST}/mongodb-${ARCHIVE_DATETIME}.gz

# Delete backups older than $KEEP_DAYS days
/bin/echo "Deleting backups older than ${KEEP_DAYS} days..."
find ${BAK_DEST} -type f -mtime +${KEEP_DAYS} -name "mongodb-*.gz" -delete;

# Dump databases
/bin/echo "Dumping databases to: ${ARCHIVE_PATH}"
# Mongo >= 3.2.0
/usr/bin/mongodump \
    --host="${REPLICA_SET}/${HOST_STRING}" \
    --readPreference="secondaryPreferred" \
    --archive="${ARCHIVE_PATH}" \
    --gzip

S3_ARCHIVE_URL="s3://${S3_BUCKET}/backup/mongodb/${ARCHIVE_DATETIME}.gz"
/bin/echo "Uploading backup to S3: ${S3_ARCHIVE_URL}"
#/usr/bin/s3cmd put ${ARCHIVE_PATH} ${S3_ARCHIVE_URL}
/usr/bin/aws --profile="${AWSCLI_PROFILE}" s3 cp ${ARCHIVE_PATH} ${S3_ARCHIVE_URL}