# Install mongodb on the Amazon Linux 2 AMI (HVM), SSD Volume Type - ami-08f63db601b82ff5f (64-bit x86)
# Source: https://docs.mongodb.com/manual/tutorial/install-mongodb-on-amazon/
# Source: https://docs.mongodb.com/manual/tutorial/transparent-huge-pages/

repo=$(cat <<- EOP
[mongodb-org-4.4]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/amazon/2/mongodb-org/4.4/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-4.4.asc
EOP
)

echo "$repo" | sudo tee /etc/yum.repos.d/mongodb-org-4.4.repo

sudo yum install -y mongodb-org

huepages=$(cat <<- EOP
[Unit]
Description=Disable Transparent Huge Pages (THP)
DefaultDependencies=no
After=sysinit.target local-fs.target
Before=mongod.service

[Service]
Type=oneshot
ExecStart=/bin/sh -c 'echo never | tee /sys/kernel/mm/transparent_hugepage/enabled > /dev/null'

[Install]
WantedBy=basic.target
EOP
)

echo "$huepages" | sudo tee /etc/systemd/system/disable-transparent-huge-pages.service

sudo systemctl daemon-reload

sudo systemctl start disable-transparent-huge-pages

echo "[+] Verify Huegpages is disabled?"
cat /sys/kernel/mm/transparent_hugepage/enabled

echo "[+] Configure to disable to run it on boot"
sudo systemctl enable disable-transparent-huge-pages

echo "[+] Starting mongodb"
sudo systemctl start mongod
sudo systemctl status mongod