A basic CloudFormation template for an RDS Aurora cluster.

RDS-Aurora-CloudFormation-Example.yaml

---
AWSTemplateFormatVersion: 2010-09-09

Description: >
  A basic CloudFormation template for an RDS Aurora cluster.

Parameters:
  DatabaseUsername:
    AllowedPattern: "[a-zA-Z0-9]+"
    ConstraintDescription: must be between 1 to 16 alphanumeric characters.
    Description: The database admin account user name, between 1 to 16 alphanumeric characters.
    MaxLength: '16'
    MinLength: '1'
    Type: String
  DatabasePassword:
    AllowedPattern: "[a-zA-Z0-9]+"
    ConstraintDescription: must be between 8 to 41 alphanumeric characters.
    Description: The database admin account password, between 8 to 41 alphanumeric characters.
    MaxLength: '41'
    MinLength: '8'
    NoEcho: 'true'
    Type: String

Mappings:
  '000000000000':
    us-east-1:
      Subnets:
        - subnet-00000000
        - subnet-11111111
        - subnet-22222222
      SecurityGroups:
        - sg-00000000
      InstanceType: db.r4.large
      BackupRetentionPeriod: 7

Metadata:
  AWS::CloudFormation::Interface:
    ParameterGroups:
      - Label:
          default: Database Configuration
        Parameters:
          - DatabaseUsername
          - DatabasePassword
    ParameterLabels:
      DatabaseUsername:
        default: Database Username
      DatabasePassword:
        default: Database Password

Resources:
  StackAlarmTopic:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName: Stack Alarm Topic

  DatabaseSubnetGroup:
    Type: AWS::RDS::DBSubnetGroup
    Properties:
      DBSubnetGroupDescription: CloudFormation managed DB subnet group.
      SubnetIds: !FindInMap [!Ref "AWS::AccountId", !Ref "AWS::Region", "Subnets"]

  DatabaseCluster:
    Type: AWS::RDS::DBCluster
    Properties:
      Engine: aurora
      MasterUsername: !Ref "DatabaseUsername"
      MasterUserPassword: !Ref "DatabasePassword"
      BackupRetentionPeriod: !FindInMap [!Ref "AWS::AccountId", !Ref "AWS::Region", "BackupRetentionPeriod"]
      PreferredBackupWindow: 01:00-02:00
      PreferredMaintenanceWindow: mon:03:00-mon:04:00
      DBSubnetGroupName: !Ref "DatabaseSubnetGroup"
      VpcSecurityGroupIds: !FindInMap [!Ref "AWS::AccountId", !Ref "AWS::Region", "SecurityGroups"]

  DatabasePrimaryInstance:
    Type: AWS::RDS::DBInstance
    Properties:
      Engine: aurora
      DBClusterIdentifier: !Ref "DatabaseCluster"
      DBInstanceClass: !FindInMap [!Ref "AWS::AccountId", !Ref "AWS::Region", "InstanceType"]
      DBSubnetGroupName: !Ref "DatabaseSubnetGroup"

  DatabasePrimaryCPUAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Primary database CPU utilization is over 80%.
      Namespace: AWS/RDS
      MetricName: CPUUtilization
      Unit: Percent
      Statistic: Average
      Period: 300
      EvaluationPeriods: 2
      Threshold: 80
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: DBInstanceIdentifier
          Value: !Ref "DatabasePrimaryInstance"
      AlarmActions:
        - Ref: StackAlarmTopic
      InsufficientDataActions:
        - Ref: StackAlarmTopic

  DatabasePrimaryMemoryAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Primary database freeable memory is under 700MB.
      Namespace: AWS/RDS
      MetricName: FreeableMemory
      Unit: Bytes
      Statistic: Average
      Period: 300
      EvaluationPeriods: 2
      Threshold: 700000000
      ComparisonOperator: LessThanOrEqualToThreshold
      Dimensions:
        - Name: DBInstanceIdentifier
          Value: !Ref "DatabasePrimaryInstance"
      AlarmActions:
        - Ref: StackAlarmTopic
      InsufficientDataActions:
        - Ref: StackAlarmTopic

  DatabasePrimaryReplicationAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Database replication latency is over 200ms.
      Namespace: AWS/RDS
      MetricName: AuroraReplicaLag
      Unit: Milliseconds
      Statistic: Average
      Period: 300
      EvaluationPeriods: 2
      Threshold: 200
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: DBInstanceIdentifier
          Value: !Ref "DatabaseReplicaInstance"
      AlarmActions:
        - Ref: StackAlarmTopic

  DatabaseReplicaInstance:
    Type: AWS::RDS::DBInstance
    Properties:
      Engine: aurora
      DBClusterIdentifier: !Ref "DatabaseCluster"
      DBInstanceClass: !FindInMap [!Ref "AWS::AccountId", !Ref "AWS::Region", "InstanceType"]
      DBSubnetGroupName: !Ref "DatabaseSubnetGroup"

  DatabaseReplicaCPUAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Replica database CPU utilization is over 80%.
      Namespace: AWS/RDS
      MetricName: CPUUtilization
      Unit: Percent
      Statistic: Average
      Period: 300
      EvaluationPeriods: 2
      Threshold: 80
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: DBInstanceIdentifier
          Value: !Ref "DatabaseReplicaInstance"
      AlarmActions:
        - Ref: StackAlarmTopic
      InsufficientDataActions:
        - Ref: StackAlarmTopic

  DatabaseReplicaMemoryAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Replica database freeable memory is under 700MB.
      Namespace: AWS/RDS
      MetricName: FreeableMemory
      Unit: Bytes
      Statistic: Average
      Period: 300
      EvaluationPeriods: 2
      Threshold: 700000000
      ComparisonOperator: LessThanOrEqualToThreshold
      Dimensions:
        - Name: DBInstanceIdentifier
          Value: !Ref "DatabaseReplicaInstance"
      AlarmActions:
        - Ref: StackAlarmTopic
      InsufficientDataActions:
        - Ref: StackAlarmTopic

  DatabaseReplicaReplicationAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Database replication latency is over 200ms.
      Namespace: AWS/RDS
      MetricName: AuroraReplicaLag
      Unit: Milliseconds
      Statistic: Average
      Period: 300
      EvaluationPeriods: 2
      Threshold: 200
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Dimensions:
        - Name: DBInstanceIdentifier
          Value: !Ref "DatabaseReplicaInstance"
      AlarmActions:
        - Ref: StackAlarmTopic

Thanks for publishing the gist!

Looks like a cut-and-paste duplicate between these two components:
https://gist.github.com/sjparkinson/e1c2f74475d2e8625ce4af85b892ab13#file-rds-aurora-cloudformation-example-yaml-L176
https://gist.github.com/sjparkinson/e1c2f74475d2e8625ce4af85b892ab13#file-rds-aurora-cloudformation-example-yaml-L156

👍 Yep, I had to take one of them out as well to get the template to work.

DatabasePrimaryMemoryAlarm is defined twice - it looks like the second instance should be: DatabaseReplicaMemoryAlarm

The primary and replica instances will come up in parallel where the replica might complete first and therefore become the primary of the cluster. It's fairly inconsequential, but it happened to me as I was explicitly specifying the name of each instance with "primary" and "replica" append to the name of each. You can remedy that by adding a DependsOn where the replica can't come up until the primary is complete. However, that will drastically increase the initial deployment time. Otherwise, you could change the logic ids to be agnostic about which one is the primary/replica.

Thanks for all the comments. I've gone ahead and made some changes, and fixed the copy pasta issue.

We've learnt a few things at the FT since I first wrote this template, one of the major things was to make more use of mappings instead of parameters.

Found it tricky to find a good name for the instance resources @phette, so left them as they are.

At the time of writing, we're also currently looking for a Cloud Platform Engineer for anyone interested, see https://aboutus.ft.com/en-gb/careers/current-openings.

I am just starting to write CloudFormation templates and I am trying to get this to run. First off I notice that I need to replace the '000000000000' in mappings with my user id correct? Next, is this referencing default subnets and security groups? Should I just add a VPC to this template and create my own subnets and security groups? Anything else for a newbie to know to try and get this going? Also, any good resources for me to learn all the basics of cloudformation with? I am also looking into using troposhere and/or terraform after i get a solid foundation with purring together cloudformation templates on there own. Any suggestions on these?

Thanks for any advice!!!

Ernie

My goodness, sorry @ernievd, I've only just got the notification about your comment!

I am also looking into using troposhere and/or terraform after i get a solid foundation with purring together cloudformation templates on there own. Any suggestions on these?

If you're only working with AWS resources, I'd say stick with CloudFormation. The others shine best only when you are building infrastructure across a number of providers, but have to deal with more yourself such as state file management.

First off I notice that I need to replace the '000000000000' in mappings with my user id correct?

That needs to be replaced with your AWS account ID.

Next, is this referencing default subnets and security groups?

Nope, they also need to be looked up and replaced. The defaults for every AWS account will have different IDs. You may want to define your own security group as part of this template too rather than use the default ones.

Anything else for a newbie to know to try and get this going?

Hard for me to know. But if you did find out some things please do post them, I'd be interested to hear!

Again, sorry it's taken so many months to reply 😬

👍

Hi ,

I am trying to create the infra for aurora posrgres and but still it pointing port 3306 only. Even I am trying change the 'Engine: aurora Postgres' but still poinging to port 3306. kindly let me know any suggestion how mapp with aurora postgres with port 5432.

@Venkatachandu0225,

You should explicitly set the Port property to 5432 in your cloud formation template for the cluster resource. When the engine mode is provisioned it will default to 3306 for both MySQL and Postgre:

https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-rds-dbcluster.html#cfn-rds-dbcluster-port