Infrastructure Automation: AWS CloudFormation

Question 1

Need to review updates to a CloudFormation stack

before deploying them in production

Answer 1

Use change sets

Question 2

Stack deployed and manual changes were made.

Need to capture changes and update template

Answer 2

Use drift detection and use output to update

template and redeploy the stack

Question 3

Need to update new version of app on EC2 and ALB.

Must avoid DNS changes and be able to rollback

Answer 3

Update template with AutoScalingReplacingUpdate

policy and perform an update

Question 4

Need to write a single template that can be deployed

across several environments / Region

Answer 4

Use parameters to enter custom values and use Ref

intrinsic function to reference the parameter

Question 5

Tried to launch instance in a different region from a

working template and it fails

Answer 5

Probably due to incorrect AMI ID

Question 6

CloudFormation stack created for first time and fails

with ROLLBACK_COMPLETE status

Answer 6

To continue administrator must relaunch the

template to create a new stack

Question 7

Template for infrastructure in one region used to

deploy in another and fails

Answer 7

Template likely referenced an AMI that doesn’t exist

in the new region and/or services that don’t exist

Question 8

CloudFormation stack fails and returns

UPDATE_ROLLBACK_FAILED

Answer 8

Fix the error that caused the rollback to fail and then

select “Continue update rollback” in the console

Question 9

Need to deploy a single CloudFormation template across multiple accounts

Answer 9

Use StackSets

Question 10

CloudFormation deploys stack with separate VPC for each app. Fails to deploy

Answer 10

May have reached the default limit for VPCs in the

account

Question 11

Would like to manually address any issues with

CloudFormation stack creation

Answer 11

Set the OnFailure parameter to “DO_NOTHING”

Question 12

CloudFormation fails with “The image id ‘[ami-

2a69aa47]’ does not exist”

Answer 12

Most likely the template is being run in a different

region where the AMI does not exist

Question 13

When creating Stack a wait condition error is
experienced: ““received 0 signals out of the 1
expected from the EC2 instance”.”

Answer 13

Check instance has a route through NAT device and in
the cfn logs confirm that the cfn-signal command ran
successfully