YAML中的双冒号是什么？AWS CloudFormation示例解析

Hey there! Those double colons (::) you see in CloudFormation templates like "Type": "AWS::EC2::KeyPair::KeyName" follow a simple, structured naming convention that makes it easy to parse exactly what you're referencing. Let's break it down step by step:

• First segment (AWS): This is a fixed prefix that tells you this is an official AWS-provided resource, property, or nested type—not a custom resource you or someone else created.
• Second segment (EC2): This specifies the AWS service the element belongs to. In this case, it's Elastic Compute Cloud (EC2), AWS's virtual server service.
• Third segment (KeyPair): This is the specific CloudFormation resource type within that service. Here, it's the EC2 Key Pair resource, which manages SSH/RDP access keys for your instances.
• Fourth segment (KeyName): This is a property (or sometimes a nested sub-resource) of the preceding resource type. For KeyPair, KeyName is the attribute that defines the name of your EC2 key pair.

Think of it like a hierarchical "address" for AWS resources: AWS::[Service]::[ResourceType]::[Property]—each :: separates a level of context, so you always know exactly which part of AWS's ecosystem you're configuring.

This convention is consistent across all CloudFormation resources, so once you get the hang of it, you'll instantly recognize what any AWS::X::Y::Z reference is pointing to.

内容的提问来源于stack exchange，提问作者Taha