AWS::CloudFormation::Init not executing commands in metadata - amazon-web-services

Question

This is my template with a test command in the metadata. I can't figure out why the command doesn't get executed. It's supposed to save a string to a file in /tmp.
The machine is Ubuntu 16.04 with cloud-init installed. In UserData I install the helper scripts and execute cfn-init.
Thanks for your help.
{
"AWSTemplateFormatVersion": "2010-09-09",
"Metadata": {
"AWS::CloudFormation::Designer": {
"2af5b799-f6bf-7f20-a6eb-943274f18373": {
"size": {
"width": 60,
"height": 60
},
"position": {
"x": 326,
"y": 118
},
"z": 0,
"embeds": []
}
}
},
"Resources": {
"EC2I3WADD": {
"Type": "AWS::EC2::Instance",
"Properties": {
"ImageId": "ami-c60b90d1",
"KeyName": "CF-KEY",
"InstanceType": "t2.micro",
"UserData": {
"Fn::Base64": {
"Fn::Join": [
"",
[
"#!/bin/bash -xe\n",
"apt-get -y install python-setuptools\n",
"mkdir aws-cfn-bootstrap-latest\n",
"curl https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz | tar xz -C aws-cfn-bootstrap-latest --strip-components 1\n",
"easy_install aws-cfn-bootstrap-latest\n",
"/usr/local/bin/cfn-init --stack ",
{
"Ref": "AWS::StackName"
},
" --resource WebServer",
" --region ",
{
"Ref": "AWS::Region"
},
"\n"
]
]
}
}
},
"Metadata": {
"AWS::CloudFormation::Designer": {
"id": "2af5b799-f6bf-7f20-a6eb-943274f18373"
},
"AWS::CloudFormation::Init": {
"config": {
"commands": {
"test": {
"command": "echo \"$MAGIC\" > /tmp/test.txt",
"env": {
"MAGIC": "I come from the environment!"
}
}
}
}
}
}
}
}
}

Answer 1

The issue is likely being cause by an incorrect --resource argument being passed to the cfn-init command within your UserData. This argument should match the logical resource name of the resource containing the MetaData, in your case EC2I3WADD.
"/usr/local/bin/cfn-init --stack ", { "Ref": "AWS::StackName" }, " --resource EC2I3WADD", " --region ", { "Ref": "AWS::Region" }
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-init.html