[Solved] You wrote this YAML snippet for a CloudFormation template but it fails to deploy:Resources: MyInstance: Type: AWS::EC2::Instance Properties: ImageId: ami-12345678 InstanceType: t2.... | AWS

AWS - CloudFormation

You wrote this YAML snippet for a CloudFormation template but it fails to deploy:

Resources:
  MyInstance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: ami-12345678
      InstanceType: t2.micro
      SecurityGroups: my-security-group

What is the likely error?

AInstanceType is invalid for EC2

BImageId must be a number, not a string

CSecurityGroups should be a list, not a single string

DResources section name is misspelled

Step-by-Step Solution

Solution:

Step 1: Check the SecurityGroups property format
SecurityGroups expects a list of strings, but here it is a single string.
Step 2: Validate other properties
ImageId is a string (correct), InstanceType is valid, Resources is spelled correctly.
Final Answer:
SecurityGroups should be a list, not a single string -> Option C
Quick Check:
SecurityGroups needs list format = A [OK]

Quick Trick: Lists must be in brackets or dash format in YAML [OK]

Common Mistakes:

Using string instead of list for SecurityGroups
Assuming ImageId is numeric
Misspelling Resources section

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More AWS Quizzes

You wrote this YAML snippet for a CloudFormation template but it fails to deploy:

Step 1: Check the SecurityGroups property format

Step 2: Validate other properties

Final Answer:

Quick Check:

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