AWS DB instance does not get all minor upgrades automatically

Description

When Amazon Relational Database Service (Amazon RDS) supports a new version of a database engine, you can upgrade your DB instances to the new version. There are two kinds of upgrades: major version upgrades and minor version upgrades. Minor upgrades helps maintain a secure and stable RDS with minimal impact on the application. For this reason, we recommend that your automatic minor upgrade is enabled. Minor version upgrades only occur automatically if a minor upgrade replaces an unsafe version, such as a minor upgrade that contains bug fixes for a previous version.

Fix - Runtime

AWS Console

Enable RDS auto minor version upgrades.

1. Go to the AWS console RDS dashboard.
2. In the navigation pane, choose Instances.
3. Select the database instance you wish to configure.
4. From the Instance actions menu, select Modify.
5. Under the Maintenance section, choose Yes for Auto minor version upgrade.
6. Select Continue and then Modify DB Instance.

CLI Command

aws rds modify-db-instance \
  --region ${region} \
  --db-instance-identifier ${resource_name} \
  --auto-minor-version-upgrade \
  --apply-immediately

Fix - Buildtime

CloudFormation

Resources:
  Example:
    Type: 'AWS::RDS::DBInstance'
    Properties:
      DBName: 'example'
      DBInstanceClass: 'db.t3.micro'
      Engine: 'mysql'
      MasterUsername: 'master'
      MasterUserPassword: 'password'
+     AutoMinorVersionUpgrade: true

Terraform

resource "aws_db_instance" "example" {
  allocated_storage          = 20
  engine                     = "mysql"
  engine_version             = "5.7"
  instance_class             = "db.t3.micro"
  name                       = "mydb"
  username                   = "foo"
  password                   = "foobarbaz"
  parameter_group_name       = "default.mysql5.7"
+ auto_minor_version_upgrade = true
}