EC2Launch

EC2Launch is the AWS-built equivalent of cloud-init for Windows instances. Just as our study of Windows instances we will learn this by its differences to cloud-init.

1 Background

Just as with our linux EC2 instances: we wish to run certain commands on our windows instances at launch. Possibilities include:

EC2Launch provides similar capabilities to cloud-init. We have already provisioned windows instances, learned how to connect to them and have installed SSH via Powershell. We also have met cloud-init on Linux. Today’s lab blends these strands.

2 EC2Launch

EC2 launch works together with IMDS. Commands to be run by EC2Launch are provided as user data by IMDS. EC2Launch executes the provided script as Administrator using either the Command.exe or PowerShell interpreter.

EC2Launch is the same process that re-sets the administrator password, encrypts it using your public key and then returns it to AWS.

3 Scenario

We wish to provision a Windows Server. Without user intervention, we wish to install SSH server and the Internet Information Services (IIS) web server.

The setup script ec2launch_setup.ps1 will create an intial VPC setup suitable for Windows server. It will also set powershell variables VpcId, SubnetId, SGId for you.

3.1 User data script

User data can be created by simply wrapping the appropriate PowerShell commands:

3.2 Launch commands

# launch windows instance and get the Instance ID
$InstanceId=(aws ec2 run-instances `
--subnet-id $SubnetId `
--image-id $ImageId `
--instance-type t2.micro `
--subnet-id $SubnetId `
--security-group-ids $SGId `
--key-name LAB_KEY `
--user-data file://userdata_windows.ps1
| ConvertFrom-Json).Instances.InstanceId

# find out the public IP
$PublicIpAddress=(aws ec2 describe-instances `
--instance-id $InstanceId `
| ConvertFrom-Json).Reservations.Instances.PublicIpAddress

# determine password data (from last class)
aws ec2 get-password-data `
--instance-id $InstanceId `
--priv-launch-key C:\Users\peadar\.ssh\id_rsa

4 Verifying User Data Script has run

2020/11/20 15:15:54Z: Userdata execution begins
2020/11/20 15:15:54Z: Zero or more than one <persist> tag was not provided
2020/11/20 15:15:54Z: Unregistering the persist scheduled task
2020/11/20 15:15:57Z: Zero or more than one <runAsLocalSystem> tag was not provided
2020/11/20 15:15:57Z: Zero or more than one <script> tag was not provided
2020/11/20 15:15:57Z: Zero or more than one <powershellArguments> tag was not provided
2020/11/20 15:15:57Z: <powershell> tag was provided.. running powershell content
2020/11/20 15:42:11Z: Userdata execution begins
2020/11/20 15:42:11Z: Zero or more than one <persist> tag was not provided
2020/11/20 15:42:11Z: Unregistering the persist scheduled task
2020/11/20 15:42:16Z: Zero or more than one <runAsLocalSystem> tag was not provided
2020/11/20 15:42:16Z: Zero or more than one <script> tag was not provided
2020/11/20 15:42:16Z: Zero or more than one <powershellArguments> tag was not provided
2020/11/20 15:42:16Z: <powershell> tag was provided.. running powershell content
2020/11/20 15:44:21Z: Userdata:  is currently executing. To end it kill the process with id: 2308
2020/11/20 15:45:59Z: Message: The output from user scripts:

Path          :
Online        : True
RestartNeeded : False

2020/11/20 15:45:59Z: Userdata execution done