2: CloudFormation Wait Conditions & Creation Policies

What are wait conditions for?

• It’s a CF resource, like anything else
  • AWS::CloudFormation::WaitCondition
• Makes the stack wait until key systems are operational
  • Wait for a count of success signals
  • Could use a timeout
  • E.g. a NAT instance has to be configured before private instances try to hit the web
• For when we need to time things carefully, e.g.:
  • Ec2 instance needs stuff installed before continuing template build
• Hybrid environment: Signal to and from on-prem systems

What’s a creation policy?

• It’s an attribute associated with(in) resources
• Wait conditions are independent resources
• Recommended for ec2 and auto-scaling groups (ASG’s)