These are the slides from the December 19, 2018 AWS Atlanta Meetup Group. The topic was cloudformation conditionals and using them in your cloud formation templates (both JSON and YAML) to enhance your templates to make them more powerful.

8. Using Parameters

9. Condition Functions

10. Condition Functions

11. What are Conditions in CloudFormation?

12. What are Conditions in CloudFormation?

13. "Conditions": {
”2EBSCondition": {
"Fn::Or": [
{
"Fn::Equals": [
{ Ref": "NumberOfEBSvolumes” },
"1"
]
},
{ "Condition": "2EBSCondition"},
{ "Condition": "3EBSCondition”},
{ "Condition": "4EBSCondition”},
{ "Condition": "5EBSCondition”},
{ "Condition": "6EBSCondition"},
{ "Condition": "7EBSCondition"},
{ "Condition": "8EBSCondition”}
]
},

14. Combining with
Parameters
"NumberOfEBSvolumes": {
"AllowedValues": [
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8"
],
"Default": "1",
"Description": "Enter the number of EBS Volumes",
"Type": "String"
},
NumberOfEBSvolumes

15. Using the
Condition within
the Resources
"diskspace2":{
"Type":"AWS::CloudWatch::Alarm",
"Condition" : "2EBSCondition",
"Properties":{
"AlarmDescription":{"Fn::Join":["",[{"Ref":"Ec2Ins
tanceID"}, "2nd Disk Utilization"]]},
"MetricName": "DiskSpaceUtilization",
"Namespace": "System/Linux",
"Statistic": "Average",
"Period": {"Ref": "UsagePeriod"},
"EvaluationPeriods": {"Ref": "EvaluationCount"},
"Threshold": {"Ref": "AlarmThreshHoldDisk"},
"AlarmActions": [{"Ref": "SNSTopic"}],
"OKActions": [{"Ref": "SNSTopic"}],
"Dimensions": [{"Name":"InstanceId",
"Value":{"Ref": "Ec2InstanceID"}},
{"Name": "Filesystem", "Value": {"Ref":
"MountFilesystemSecondary"}},
{"Name": "MountPath", "Value": {"Ref":
"MountPointSecondary" }} ],
"ComparisonOperator":
"GreaterThanOrEqualToThreshold"}
},

16. Grouping Parameters with Metadata

17. Parameter
Groups
"Metadata": {
"AWS::CloudFormation::Interface": {
"ParameterGroups": [
{
"Label": {
"default": "CloudWatch Alarm Parameters"
},
"Parameters": [
"AlarmThreshHoldMem",
"AlarmThreshHoldCPU",
"AlarmThreshHoldDisk",
"UsagePeriod",
"Environment",
"EvaluationCount",
"NumberOfEBSvolumes"
]
},