AWS WaitCondition Wait for provision - amazon-web-services

Question

I am trying to learn Cloudformation im stuck with a senario where I need a second EC2 instance started after one EC2 is provisioned and good to go.
This is what i have in UserData of Instance one
"#!/bin/bash\n",
"#############################################################################################\n",
"sudo add-apt-repository ppa:fkrull/deadsnakes\n",
"sudo apt-get update\n",
"curl -sL https://deb.nodesource.com/setup_7.x | sudo -E bash -\n",
"sudo apt-get install build-essential libssl-dev python2.7 python-setuptools -y\n",
"#############################################################################################\n",
"Install Easy Install",
"#############################################################################################\n",
"easy_install https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz\n",
"#############################################################################################\n",
"#############################################################################################\n",
"GIT LFS Repo",
"#############################################################################################\n",
"curl -s https://packagecloud.io/install/repositories/github/git-lfs/script.deb.sh | sudo bash\n",
"#############################################################################################\n",
"cfn-init",
" --stack ",
{
"Ref": "AWS::StackName"
},
" --resource UI",
" --configsets InstallAndRun ",
" --region ",
{
"Ref": "AWS::Region"
},
"\n",
"#############################################################################################\n",
"# Signal the status from cfn-init\n",
"cfn-signal -e 0 ",
" --stack ",
{
"Ref": "AWS::StackName"
},
" --resource UI",
" --region ",
{
"Ref": "AWS::Region"
},
" ",
{
"Ref": "WaitHandleUIConfig"
},
"\n"
I have a WaitCondition , which i think is whats used to do this
"WaitHandleUIConfig" : {
"Type" : "AWS::CloudFormation::WaitConditionHandle",
"Properties" : {}
},
"WaitConditionUIConfig" : {
"Type" : "AWS::CloudFormation::WaitCondition",
"DependsOn" : "UI",
"Properties" : {
"Handle" : { "Ref" : "WaitHandleUIConfig" },
"Timeout" : "500"
}
}
In the Instance i use the DependsOn in the second instance to wait for first instance.
"Service": {
"Type": "AWS::EC2::Instance",
"Properties": {
},
"Metadata": {
"AWS::CloudFormation::Designer": {
"id": "1ba546d0-2bad-4b68-af47-6e35159290ca"
},
},
"DependsOn":"WaitConditionUIConfig"
}
this isnt working. I keep getting the error
WaitCondition timed out. Received 0 conditions when expecting 1
Any help would be appreciated.
Thanks

Answer 1

Put quotes around the Handle
Change this
" ",
{
"Ref": "WaitHandleUIConfig"
},
"\n"
to this
" \"",
{
"Ref": "WaitHandleUIConfig"
},
"\"\n"

Answer 2

Remove --stack, --resource and --region from your cfn-signal command. These are only used when 'resource signaling', not when signaling using a Wait Condition Handle. (You might also need to add an --id option, but the documentation says this is not required.)
For further debugging, examine the /var/log/cloud-init-output.log file on the EC2 instance to view any further cloud-init errors that might fail to successfully send the signal to your wait condition.
You might also want to comment and newline the descriptions "Install Easy Install", and "GIT LFS Repo",, e.g., "# Install Easy Install\n",, these syntax issues shouldn't cause your script to fail but will output 'command not found' errors to appear in your log.