Electric is well documented here, but this note will help explain our use.

We host our sync engine on an EC2 instance with EBS volume. It runs inside of a docker container, which makes things considerably easier, but there are still quirks.

When the instance is created we run the userData and we will break it down

First we update cli tools, install docker, and then start docker:

apt-get update -y

apt-get install -y docker.io

systemctl start docker

Next we have to determine what device is being used. The device names are not always the same for EBS volume, they are randomly assigned with some rules.

Once we find the volume attachment we can format it and move it to the proper location for electric.

DEVICE=""

if lsblk | grep -q xvdf; then

DEVICE="/dev/xvdf"

elif lsblk | grep -q nvme1n1; then

DEVICE="/dev/nvme1n1"

else

echo "ERROR: Could not find attached EBS volume (xvdf or nvme1n1)"

exit 1

fi

  

if ! sudo blkid $DEVICE; then

sudo mkfs.ext4 $DEVICE

fi

  

sudo mkdir -p /persistent

sudo mount $DEVICE /persistent

After that we run the docker instance.

sudo docker pull ${ELECTRIC_IMAGE}

  

sudo docker run -d -p 80:${ELECTRIC_PORT} \

--name electric \

--restart=always \

-e DATABASE_URL="${connection.value}" \

-e ELECTRIC_SECRET="${secrets.ElectricSecret.value}" \

-e ELECTRIC_INSECURE="false" \

-v /persistent:/persistent \

${ELECTRIC_IMAGE}

It is important to know that we have no automatic reboot script at this point.

In the event of debugging or reboot. You can us SSM

aws ssm start-session --target i-****

Once you get inside you can use sudo docker * to run any commands, logging, etc that you might need.