Cloudformation fails with “AMI cannot be described”

Ok Solved.

I randomly decided that, to better debug, I would make a min instance count of 1. This threw up an error about my launchConfig. After some trolling around I found out that I had made a really big mistake with my template. So I changed the launchConfig to:

"LaunchConfig" : {
  "Type" : "AWS::AutoScaling::LaunchConfiguration",
  "Metadata" : {
    "Comment" : "Install a simple PHP application",
    "AWS::CloudFormation::Init" : {
       "config" : {
        "files" : {
          "/etc/cron.d/worker" : {
            "content" : "*/1 * * * * ubuntu /home/ubuntu/worker_cronjob &> /home/ubuntu/worker.log\n",
            "mode"    : "000644",
            "owner"   : "root",
            "group"   : "root"
          },

          "/home/ubuntu/worker_cronjob" : {
            "content" : { "Fn::Join" : ["", [
                "#!/usr/bin/env php\n",
                "<?php\n",
                "define('ROOT', dirname(__FILE__));",
                "const AWS_KEY = \"", { "Ref" : "WorkerKeys" }, "\";",
                "const AWS_SECRET = \"", { "Fn::GetAtt": ["WorkerKeys", "SecretAccessKey"]}, "\";",
                "const QUEUE = \"", { "Ref" : "InputQueue" }, "\";",
                "exec('git clone x '.ROOT.'/worker');",
                "if(!file_exists(ROOT.'/worker/worker_despatcher.php')){",
                "echo 'git not downloaded right';",
                "exit();",
                "}",
                "echo 'git downloaded';",
                "include_once ROOT.'/worker/worker_despatcher.php';"
            ]]},
            "mode"    : "000755",
            "owner"   : "ubuntu",
            "group"   : "ubuntu"
          }
        }
      }
    }
  },

And my userdata to:

    "UserData"       : { "Fn::Base64" : { "Fn::Join" : ["", [
      "#!/bin/bash\n",
      "apt-get -y install python-setuptools\n",
      "easy_install https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz\n",
      "cfn-init -v ",
      "         -s ", { "Ref" : "AWS::StackName" },
      "         -r LaunchConfig ",
      "         --access-key ", { "Ref" : "WorkerKeys" },
      "         --secret-key ", {"Fn::GetAtt": ["WorkerKeys", "SecretAccessKey"]},
      "         --region ", { "Ref" : "AWS::Region" }, "\n"
    ]]}

And now everything works dandy.

So if you get the users-script error it means that your launch config is wrong and you should look at it again.

Thanks for the help :)

I just figured it out! The parameter --resource of cfn-init script have to be set with the Launch Configuration name and not the AutoScale Group name. Wish that could help someone :)