relaunch

#!/bin/bash

PATH=/usr/local/bin/:$PATH

if [ "$1" = "" ]; then echo "USER ERROR: please specify a configuration file"; exit -1; fi
DIR=$(readlink -m $(dirname $0))
PATH=.:$PATH . $1 || exit -1

if [ "$ec2spotter_image_name" = "" ]
then
  echo "image name not specified";
  exit -1;
fi

SELF=$(curl -s http://169.254.169.254/latest/meta-data/instance-id)
IMAGE_ID=$(aws ec2 describe-images --filters Name=tag-key,Values="Name" Name=tag-value,Values=$ec2spotter_image_name --owners self \
   |jq -r '.Images[0].ImageId')

if [ "$ec2spotter_reuse_images" != 1 ] && [ $IMAGE_ID != "null" ] && [ $IMAGE_ID != "" ]
then
	aws ec2 deregister-image --image-id $IMAGE_ID
fi

if [ "$ec2spotter_reuse_images" != 1 ]
then
	echo "Creating AMI image."
	sync
	IMAGE_ID=$(aws ec2 create-image --instance-id $SELF --no-reboot --name $ec2spotter_image_name | jq -r '.ImageId')
	while [ ! $(aws ec2 describe-images --image-ids $IMAGE_ID | jq -r '.Images[0].State') = "available" ]
	do
	  sleep 5
	  echo "Waiting for image $IMAGE_ID"
	done
	SNAPSHOT_ID=$(aws ec2 describe-images --image-id $IMAGE_ID |jq -r '.Images[0].BlockDeviceMappings[0].Ebs.SnapshotId')
	aws ec2 create-tags --resources $IMAGE_ID $SNAPSHOT_ID --tags Key=Name,Value=$ec2spotter_image_name
else
	echo "Re-using image with id=$IMAGE_ID"
fi

REGION=$(curl -s http://169.254.169.254/latest/meta-data/placement/availability-zone | sed -e 's/.$//')
PUB_KEY=$(wget -q -O - http://169.254.169.254/latest/meta-data/public-keys | awk -F= '{print $2}')
HOSTNAME=$(hostname)

# Setup the script that runs in the spot instance. It is responsible for cleaning up the temporary objects created during launch.
cat >user-data.tmp <<EOF
#!/bin/sh
my_id=\$(curl -s http://169.254.169.254/latest/meta-data/instance-id)
my_root_vol_id=\$(aws ec2 describe-instances --instance-id \$my_id | jq -r '.Reservations[0].Instances[0].BlockDeviceMappings[0].Ebs.VolumeId')
aws ec2 create-tags --resources \$my_id \$my_root_vol_id --tags Key=Name,Value="${ec2spotter_image_name}-spot"

echo '@reboot $DIR/self-spot' > /tmp/crontab
crontab -l >> /tmp/crontab
crontab < /tmp/crontab

echo $SELF > /etc/ec2spotter
echo $HOSTNAME > /etc/hostname
echo "echo Launching new spot instance: \$my_id $ec2spotter_elastic_ip, spotted by: $SELF $ec2spotter_control_ip; aws ec2 associate-address --instance-id \$my_id --allocation-id $ec2spotter_elastic_ip --allow-reassociation; aws ec2 associate-address --instance-id $SELF --allocation-id $ec2spotter_control_ip --allow-reassociation" | at now + 5 minutes
shutdown -r now

EOF

userData=$(base64 user-data.tmp | tr -d '\n');

sortedPrices=$(aws ec2 describe-spot-price-history --product-descriptions Linux/UNIX --instance-types $ec2spotter_instance_type --max-items 25 | jq -r '.SpotPriceHistory | sort_by(.SpotPrice)')

medianPrice=$(echo $sortedPrices| jq -r '.[18].SpotPrice')
cheapZone=$(echo $sortedPrices | jq -r '.[0].AvailabilityZone')

echo "Selected medianPrice=$medianPrice in zone $cheapZone" >&2
echo "Absolute lowest price was " $(echo $sortedPrices| jq -r '.[0].SpotPrice') >&2
echo "Absolute highest price was " $(echo $sortedPrices| jq -r '.[24].SpotPrice') >&2

cat >specs.tmp <<EOF
{
  "KeyName" : "$PUB_KEY",
  "InstanceType": "$ec2spotter_instance_type",
  "ImageId" : "$IMAGE_ID",
  "UserData" : "${userData}",
  "Placement": {
    "AvailabilityZone": "$cheapZone"
  },
  "BlockDeviceMappings": [
    {
      "DeviceName" : "/dev/sda1",
      "Ebs": {
        "VolumeSize": $ec2spotter_volume_size,
        "DeleteOnTermination": true,
        "VolumeType" : "gp2"
      }
    }
  ]
}
EOF

targetPrice=$medianPrice
#if [ $targetPrice -gt $ec2spotter_bid_price ]
#then
#	targetPrice=$ec2spotter_bid_price
#	echo "targetPrice capped at $ec2spotter_bid_price" >&2
#fi

SPOT_JSON=$(aws ec2 request-spot-instances --spot-price $targetPrice --type one-time --launch-specification file://specs.tmp --region ${REGION})

SPOT_ID=$(echo $SPOT_JSON | jq -r '.SpotInstanceRequests[0].SpotInstanceRequestId')

echo SPOT_ID=$SPOT_ID

aws ec2 create-tags --resources ${SPOT_ID} --tags Key=Name,Value=${ec2spotter_image_name} --region ${REGION}

echo $SPOT_JSON > spot.tmp