cloudformation lore

🔧 Core Functions:

• !Ref → get value of param or resource
• !GetAtt → get attribute (e.g. !GetAtt EC2Instance.PublicIp)
• !Sub → string interpolation (${})
• !Join → concat strings
• !If, !Equals, !Not, !Or, !And → conditions
• !Select, !Split, !FindInMap → array/map helpers

🔄 Pseudo Parameters:

• ${AWS::Region}
• ${AWS::AccountId}
• ${AWS::StackName}
• ${AWS::Partition}
• ${AWS::NoValue} → used to remove a property conditionally

🧩 Intrinsics & Helpers:

• Mappings → key-value lookup table
• Conditions → used to control resource creation
• DependsOn → control resource dependency
• Metadata → for tooling (e.g., cfn-init)
• CreationPolicy, UpdatePolicy, DeletionPolicy → lifecycle control

📦 Template Sections:

• Parameters → user inputs
• Resources → actual AWS stuff
• Outputs → expose values
• Mappings, Conditions, Metadata, Rules

Master these, and you’re 90% CloudFormation-ready.