07_rds-mappings.yml

---
AWSTemplateFormatVersion: "2010-09-09"
Description: "RDS instance for various environments"

Parameters:
  Environment:
    Type: String
    AllowedValues:
      - dev
      - stage
      - prod

# https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/conditions-section-structure.html
# https://github.com/awsdocs/aws-cloudformation-user-guide/issues/3
Conditions:
  Prod: !Equals [ !Ref Environment, prod ] # yaml shorthand could be confusing (!=)
   # !Equals
   # Fn::Equals:

Mappings:

  AttributesByEnvironment:
    dev:
      AllocatedStorage: 10
      BackupRetentionPeriod: 5
      DBInstanceClass: db.m4.large
      Iops: 1000
      MultiAZ: False
    stage:
      AllocatedStorage: 100
      BackupRetentionPeriod: 5
      DBInstanceClass: db.m4.2xlarge
      Iops: 3000
      MultiAZ: False
    prod:
      AllocatedStorage: 100
      BackupRetentionPeriod: 35
      DBInstanceClass: db.m4.2xlarge
      Iops: 3000
      MultiAZ: True

Resources:
  RdsDbInstance:
    Type: "AWS::RDS::DBInstance"
    Properties:
      AllocatedStorage: !FindInMap [AttributesByEnvironment, !Ref Environment, "AllocatedStorage"] # https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-conditions.html
      AllowMajorVersionUpgrade: false
      AutoMinorVersionUpgrade: true
      BackupRetentionPeriod: !FindInMap [AttributesByEnvironment, !Ref Environment, "BackupRetentionPeriod"]
      DBClusterIdentifier: myDBCluster # reminder: see update requires replacement
      DBInstanceClass: !FindInMap [AttributesByEnvironment, !Ref Environment, "DBInstanceClass"]
      Engine: postgres # https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBInstance.html
      EngineVersion: 9.6.6
      Iops: !FindInMap [AttributesByEnvironment, !Ref Environment, "Iops"]
      MultiAZ: !Condition Prod
      StorageEncrypted: !Condition Prod
      StorageType: io1
      Tags:
        - Name: Environment
          Value: !Ref Environment