Why won't CloudFormation execute my command?

Question

I'm using this CloudFormation script to create a Windows instance and install Web Deploy:

{
  "AWSTemplateFormatVersion" : "2010-09-09",

  "Description" : "Test.",

  "Resources" : {

    "InstanceSecurityGroup" : {
      "Type" : "AWS::EC2::SecurityGroup",
      "Properties" : {
        "GroupDescription" : "Enable RDP",
        "SecurityGroupIngress" : [
          {"IpProtocol" : "tcp", "FromPort" : "3389", "ToPort" : "3389", "CidrIp" : "0.0.0.0/0"}
        ]
      }
    },

    "WindowsServer": {
      "Type" : "AWS::EC2::Instance",
      "Metadata" : {
        "AWS::CloudFormation::Init" : {
          "config" : {
            "files" : {
              "c:\\Packages\\WebDeploy_amd64_en-US.msi" : {
                "source" : "http://download.microsoft.com/download/1/B/3/1B3F8377-CFE1-4B40-8402-AE1FC6A0A8C3/WebDeploy_amd64_en-US.msi"
              }
            }
          },
          "commands" : {
            "1-installwebdeploy" : {
              "command" : "msiexec.exe /i c:\\Packages\\WebDeploy_amd64_en-US.msi ADDLOCAL=ALL /qn /norestart"
            }
          }
        }
      },

      "Properties": {
        "InstanceType" : "m1.small",
        "ImageId" : "ami-bbf2e1cf",
        "SecurityGroups" : [ {"Ref" : "InstanceSecurityGroup"} ],
        "KeyName" : "POP",
        "UserData" : { "Fn::Base64" : { "Fn::Join" : ["", [
            "<script>\n",

            "cfn-init.exe -v -s ", { "Ref" : "AWS::StackId" }, 
            " -r WindowsServer",
            " --region ", { "Ref" : "AWS::Region" }, "\n",

            "</script>"
        ]]}}
      }
    }
  }
}

The MSI package correctly downloads, but the command does not execute. In fact, the cfn-init.log states that no commands were specified:

2013-07-23 12:57:10,740 [DEBUG] CloudFormation client initialized with endpoint https://cloudformation.eu-west-1.amazonaws.com
2013-07-23 12:57:10,740 [DEBUG] Describing resource WindowsServer in stack ***
2013-07-23 12:57:14,079 [DEBUG] Creating Scheduled Task for cfn-init resume
2013-07-23 12:57:14,220 [DEBUG] Scheduled Task created
2013-07-23 12:57:14,328 [INFO] Running configSets: default
2013-07-23 12:57:14,328 [INFO] Running configSet default
2013-07-23 12:57:14,328 [INFO] Running config config
2013-07-23 12:57:14,328 [DEBUG] No packages specified
2013-07-23 12:57:14,328 [DEBUG] No groups specified
2013-07-23 12:57:14,328 [DEBUG] No users specified
2013-07-23 12:57:14,328 [DEBUG] No sources specified
2013-07-23 12:57:14,328 [DEBUG] Parent directory c:\Packages does not exist, creating
2013-07-23 12:57:14,328 [DEBUG] Writing content to c:\Packages\WebDeploy_amd64_en-US.msi
2013-07-23 12:57:14,328 [DEBUG] Retrieving contents from http://download.microsoft.com/download/1/B/3/1B3F8377-CFE1-4B40-8402-AE1FC6A0A8C3/WebDeploy_amd64_en-US.msi
2013-07-23 12:57:14,673 [DEBUG] No mode specified for c:\Packages\WebDeploy_amd64_en-US.msi
2013-07-23 12:57:14,673 [WARNING] Unsupported OS for setting owner/group: nt
2013-07-23 12:57:14,673 [DEBUG] No commands specified
2013-07-23 12:57:14,673 [DEBUG] No services specified
2013-07-23 12:57:14,673 [INFO] ConfigSets completed
2013-07-23 12:57:14,734 [DEBUG] Deleting Scheduled Task for cfn-init resume
2013-07-23 12:57:14,796 [DEBUG] Scheduled Task deleted

What exactly is going on here? Thanks in advance.

Answer 1

Your commands block should be nested inside the config block, at the moment it is at the same level in the hierarchy.

    "AWS::CloudFormation::Init" : {
      "config" : {
        "files" : {
          "c:\\Packages\\WebDeploy_amd64_en-US.msi" : {
            "source" : "http://download.microsoft.com/download/1/B/3/1B3F8377-CFE1-4B40-8402-AE1FC6A0A8C3/WebDeploy_amd64_en-US.msi"
          }
        },
        "commands" : {
          "1-installwebdeploy" : {
            "command" : "msiexec.exe /i c:\\Packages\\WebDeploy_amd64_en-US.msi ADDLOCAL=ALL /qn /norestart"
          }
        }
      },
    }