Adding Custom Metric to CloudFormation template - amazon-web-services

Question

I need to add an alarm the triggers a rollback in CloudFormation. I've settled on adding a custom metric that can be assigned manually. I'm looking at the documentation here. This looks like it would work but I need it to be added to the template. Is this possible? The way I'm thinking initially the value would be 0 failures like below
aws cloudwatch put-metric-data --metric-name Failures --namespace MyNamespace --value 0
when I want to trigger a rollback I would set it to 1
aws cloudwatch put-metric-data --metric-name Failures --namespace MyNamespace --value 1
But I need this to be in the template so that I can have access to the correct/dynamic value of the namespace when defining the alarm.

Answer 1

You can use cloudformation simple template to add metrics
resource "AWS::Logs::MetricFilter" specifies a metric filter that
describes how CloudWatch Logs extracts information from logs and
transforms it into Amazon CloudWatch metrics. If you have multiple
metric filters that are associated with a log group, all the filters
are applied to the log streams in that group.
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-logs-metricfilter.html
sample
404MetricFilter:
Type: AWS::Logs::MetricFilter
Properties:
LogGroupName:
Ref: "myLogGroup"
FilterPattern: "[ip, identity, user_id, timestamp, request, status_code = 404, size]"
MetricTransformations:
-
MetricValue: "1"
MetricNamespace: "WebServer/404s"
MetricName: "404Count"

Answer 2

unless you want to do this via a cloudformation custom resource
you can use this as well Running bash commands in AWS CloudFormation templates
With the above you can run your command like
Resources:
CommandRunner:
Type: AWSUtility::CloudFormation::CommandRunner
Properties:
Command: 'aws cloudwatch put-metric-data --metric-name Failures --namespace MyNamespace --value 1'