cloudformation templates for alaram dashboard - aws-cloudformation

Question

I have created CloudFormation templates for CloudWatch dashboard and I am trying to use the AlarmName parameter but Ref value not passing as well as getting error in AWS CloudFormation below.
The field DashboardBody must be a valid JSON object (Service: AmazonCloudWatch; Status Code: 400; Error Code: InvalidParameterInput;
Request ID: e88b103e-8fba-42bc-b825-ed0e4bd6749a; Proxy: null)
Template:
AWSTemplateFormatVersion: 2010-09-09
Description: "AWS CloudFormation Sample Template for Cloudwatch alert and Dashboard configuration."
Parameters:
AlarmNameForCPU:
Default: Service_CpuUtilization
Description: AlarmName
MaxLength: "99"
MinLength: "1"
Type: String
AlarmNameForMemory:
Default: Service_MemoryUtilization
Description: AlarmName
MaxLength: "99"
MinLength: "1"
Type: String
DashboardName:
Default: ServiceDashboard
Description: Dashboard
MaxLength: "99"
MinLength: "1"
Type: String
DashboardTitleCPU:
Default: CpuUtilization
Description: DashboardTitle
MaxLength: "99"
MinLength: "1"
Type: String
DashboardTitleMemory:
Default: MemoryUtilization
Description: DashboardTitle
MaxLength: "99"
MinLength: "1"
Type: String
Resources:
Dashboard:
Type: "AWS::CloudWatch::Dashboard"
Properties:
DashboardName: !Ref DashboardName
DashboardBody: '{
"widgets":[
{
"height": 3,
"width": 9,
"y": 0,
"x": 0,
"type": "metric",
"properties": {
"title": "{"Ref DashboardTitleCPU"}",
"annotations": {
"alarms": [
"arn:aws:cloudwatch:us-east-1:468491150671:alarm: {"Ref" : "AlarmNameForCPU"}"
]
},
"view": "singleValue"
}
},
{
"height": 3,
"width": 9,
"y": 0,
"x": 9,
"type": "metric",
"properties": {
"title": "{"Ref DashboardTitleMemory"}",
"annotations": {
"alarms": [
"arn:aws:cloudwatch:us-east-1:468491150671:alarm: {"Ref AlarmNameForMemory"}"
]
},
"view": "singleValue"
}
}
]
}}}}]}'

Answer 1

You need to use the Sub function for that.
Resources:
Dashboard:
Type: "AWS::CloudWatch::Dashboard"
Properties:
DashboardName: !Ref DashboardName
DashboardBody: !Sub |
'{
"widgets":[
{
"height": 3,
"width": 9,
"y": 0,
"x": 0,
"type": "metric",
"properties": {
"title": "${DashboardTitleCPU}",
"annotations": {
"alarms": [
"arn:aws:cloudwatch:us-east-1:468491150671:alarm:${AlarmNameForCPU}"
]
},
"view": "singleValue"
}
},
{
"height": 3,
"width": 9,
"y": 0,
"x": 9,
"type": "metric",
"properties": {
"title": "${DashboardTitleMemory}",
"annotations": {
"alarms": [
"arn:aws:cloudwatch:us-east-1:468491150671:alarm:${AlarmNameForMemory}"
]
},
"view": "singleValue"
}
}
]
}'