ec2-elastic-ip

Init script for ubuntu that will set the ip address and hostname of an amazon spot instance using user-data.

##Quick Start

sudo pip install awscli
sudo cp ec2-elastic-ip /etc/init.d/
sudo chmod 755 /etc/init.d/ec2-elastic-ip
sudo update-rc.d ec2-elastic-ip defaults
sudo update-rc.d ec2-elastic-ip enable
sudo vi /etc/default/ec2-elastic-ip

The contents of /etc/default/ec2-elastic-ip should be:

export AWS_ACCESS_KEY_ID="xxx"
export AWS_SECRET_ACCESS_KEY="xxx/yyy"

Set the user-data on the spot instance like this:

ip=1.2.3.4&hostname=aws1.example.com

##Handle SSH Host files If you are using an elastic IP address, and a hostname, then you'll certainly want to deal with the fact that every time you start the instance, it has a different ssh host key.

To stop this from happening then for each hostname create a directory below with the host keys that you want to use. Or steal from a currently running box. I recommend that the host key's be different for each "hostname".

HOSTNAME=aws1.example.com
sudo mkdir /etc/default/ec2-elastic-ip.d/ssh/$HOSTNAME
sudo cp /etc/ssh/*host* mkdir /etc/default/ec2-elastic-ip.d/ssh/$HOSTNAME

##Use Base64 Encoding for user-data I use a script to kick off the persistent spot instance:

MY_AMI="ami-123451"
REGION="us-west-2a"
AWS_IP="1.2.3.4"
AWS_HOSTNAME="aws.example.com"
USER_DATA="ip=$AWS_IP&hostname=$AWS_HOSTNAME"
USER_DATA_B64=`echo $AWS1_USER_DATA | base64 -w0`

aws ec2 request-spot-instances --spot-price "0.10" --instance-count 1 --type "persistent" --launch-specification "{\"ImageId\":\"$MY_AMI\",\"InstanceType\": \"r3.2xlarge\",\"UserData\":\"$AWS_USER_DATA_B64\",\"Placement\":{\"AvailabilityZone\":\"$REGION\"}}"

Of course you can add additional parameters that would be ignored.

CameronGregory/ec2-elastic-ip

ec2-elastic-ip