aurora-mysql

This component is responsible for provisioning Aurora MySQL RDS clusters. It seeds relevant database information (hostnames, username, password, etc.) into AWS SSM Parameter Store.

Usage

Stack Level: Regional

Here's an example for how to use this component.

stacks/catalog/aurora-mysql/defaults.yaml file (base component for all Aurora MySQL clusters with default settings):

components:
  terraform:
    aurora-mysql/defaults:
      metadata:
        type: abstract
      vars:
        enabled: false
        name: rds
        mysql_deletion_protection: false
        mysql_storage_encrypted: true
        aurora_mysql_engine: "aurora-mysql"
        allowed_cidr_blocks:
          # all automation
          - 10.128.0.0/22
          # all corp
          - 10.128.16.0/22
        eks_component_names:
          - eks/eks
        # https://docs.aws.amazon.com/AmazonRDS/latest/AuroraMySQLReleaseNotes/AuroraMySQL.Updates.3020.html
        # aws rds describe-db-engine-versions --engine aurora-mysql --query 'DBEngineVersions[].EngineVersion'
        aurora_mysql_engine_version: "8.0.mysql_aurora.3.02.0"
        # engine and cluster family are notoriously hard to find.
        # If you know the engine version (example here is "8.0.mysql_aurora.3.02.0"), use Engine and DBParameterGroupFamily from:
        #    aws rds describe-db-engine-versions --engine aurora-mysql --query "DBEngineVersions[]" | \
        #    jq '.[] | select(.EngineVersion == "8.0.mysql_aurora.3.02.0") |
        #       { Engine: .Engine, EngineVersion: .EngineVersion, DBParameterGroupFamily: .DBParameterGroupFamily }'
        #
        #    Returns:
        #    {
        #       "Engine": "aurora-mysql",
        #       "EngineVersion": "8.0.mysql_aurora.3.02.0",
        #       "DBParameterGroupFamily": "aurora-mysql8.0"
        #     }
        aurora_mysql_cluster_family: "aurora-mysql8.0"
        mysql_name: shared
        # 1 writer, 1 reader
        mysql_cluster_size: 2
        mysql_admin_user: "" # generate random username
        mysql_admin_password: "" # generate random password
        mysql_db_name: "" # generate random db name
        # https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Concepts.DBInstanceClass.html
        mysql_instance_type: "db.t3.medium"
        mysql_skip_final_snapshot: false

Example configuration for a dev cluster. Import this file into the primary region. stacks/catalog/aurora-mysql/dev.yaml file (override the default settings for the cluster in the dev account):

import:
  - catalog/aurora-mysql/defaults

components:
  terraform:
    aurora-mysql/dev:
      metadata:
        component: aurora-mysql
        inherits:
          - aurora-mysql/defaults
      vars:
        instance_type: db.r5.large
        mysql_cluster_size: 1
        mysql_name: main
        mysql_db_name: main

Example deployment with primary cluster deployed to us-east-1 in a platform-dev account: atmos terraform apply aurora-mysql/dev -s platform-use1-dev

Disaster Recovery with Cross-Region Replication

This component is designed to support cross-region replication with continuous replication. If enabled and deployed, a secondary cluster will be deployed in a different region than the primary cluster. This approach is highly aggressive and costly, but in a disaster scenario where the primary cluster fails, the secondary cluster can be promoted to take its place. Follow these steps to handle a Disaster Recovery.

Usage

To deploy a secondary cluster for cross-region replication, add the following catalog entries to an alternative region:

Default settings for a secondary, replica cluster. For this example, this file is saved as stacks/catalog/aurora-mysql/replica/defaults.yaml

import:
  - catalog/aurora-mysql/defaults

components:
  terraform:
    aurora-mysql/replica/defaults:
      metadata:
        component: aurora-mysql
        inherits:
          - aurora-mysql/defaults
      vars:
        eks_component_names: []
        allowed_cidr_blocks:
          # all automation in primary region (where Spacelift is deployed)
          - 10.128.0.0/22
          # all corp in the same region as this cluster
          - 10.132.16.0/22
        mysql_instance_type: "db.t3.medium"
        mysql_name: "replica"
        primary_cluster_region: use1
        is_read_replica: true
        is_promoted_read_replica: false # False by default, added for visibility

Environment specific settings for dev as an example:

import:
  - catalog/aurora-mysql/replica/defaults

components:
  terraform:
    aurora-mysql/dev:
      metadata:
        component: aurora-mysql
        inherits:
          - aurora-mysql/defaults
          - aurora-mysql/replica/defaults
      vars:
        enabled: true
        primary_cluster_component: aurora-mysql/dev

Promoting the Read Replica

Promoting an existing RDS Replicate cluster to a fully standalone cluster is not currently supported by Terraform: https://github.com/hashicorp/terraform-provider-aws/issues/6749

Instead, promote the Replicate cluster with the AWS CLI command: aws rds promote-read-replica-db-cluster --db-cluster-identifier <identifier>

After promoting the replica, update the stack configuration to prevent future Terrafrom runs from re-enabling replication. In this example, modify stacks/catalog/aurora-mysql/replica/defaults.yaml

is_promoted_read_replica: true

Reploying the component should show no changes. For example, atmos terraform apply aurora-mysql/dev -s platform-use2-dev

Variables

Required Variables

aurora_mysql_cluster_family (string) required: DBParameterGroupFamily (e.g. aurora5.6, aurora-mysql5.7 for Aurora MySQL databases). See https://stackoverflow.com/a/55819394 for help finding the right one to use.
aurora_mysql_engine (string) required: Engine for Aurora database: aurora for MySQL 5.6, aurora-mysql for MySQL 5.7
region (string) required: AWS Region

Optional Variables

allow_ingress_from_vpc_accounts optional

List of account contexts to pull VPC ingress CIDR and add to cluster security group.

e.g.
{
environment = "ue2",
stage = "auto",
tenant = "core"
}

Defaults to the "vpc" component in the given account

Type:

list(object({
vpc         = optional(string, "vpc")
environment = optional(string)
stage       = optional(string)
tenant      = optional(string)
}))

Default value: [ ]

allowed_cidr_blocks (list(string)) optional

List of CIDR blocks to be allowed to connect to the RDS cluster

Default value: [ ]

aurora_mysql_cluster_parameters optional

List of DB cluster parameters to apply

Type:

list(object({
apply_method = string
name         = string
value        = string
}))

Default value: [ ]

aurora_mysql_engine_version (string) optional

Engine Version for Aurora database.

Default value: ""

aurora_mysql_instance_parameters optional

List of DB instance parameters to apply

Type:

list(object({
apply_method = string
name         = string
value        = string
}))

Default value: [ ]

auto_minor_version_upgrade (bool) optional

Automatically update the cluster when a new minor version is released

Default value: false

eks_component_names (set(string)) optional

The names of the eks components

Default value:

[
  "eks/cluster"
]

is_promoted_read_replica (bool) optional

If true, do not assign a Replication Source to the Cluster. Set to true after manually promoting the cluster from a replica to a standalone cluster.

Default value: false

is_read_replica (bool) optional

If true, create this DB cluster as a Read Replica.

Default value: false

mysql_admin_password (string) optional

MySQL password for the admin user

Default value: ""

mysql_admin_user (string) optional

MySQL admin user name

Default value: ""

mysql_backup_retention_period (number) optional

Number of days for which to retain backups

Default value: 3

mysql_backup_window (string) optional

Daily time range during which the backups happen

Default value: "07:00-09:00"

mysql_cluster_size (string) optional

MySQL cluster size

Default value: 2

mysql_db_name (string) optional

Database name (default is not to create a database

Default value: ""

mysql_deletion_protection (string) optional

Set to true to protect the database from deletion

Default value: true

mysql_enabled_cloudwatch_logs_exports (list(string)) optional

List of log types to export to cloudwatch. The following log types are supported: audit, error, general, slowquery

Default value:

[
  "audit",
  "error",
  "general",
  "slowquery"
]

mysql_instance_type (string) optional

EC2 instance type for RDS MySQL cluster

Default value: "db.t3.medium"

mysql_maintenance_window (string) optional

Weekly time range during which system maintenance can occur, in UTC

Default value: "sat:10:00-sat:10:30"

mysql_name (string) optional

MySQL solution name (part of cluster identifier)

Default value: ""

mysql_skip_final_snapshot (string) optional

Determines whether a final DB snapshot is created before the DB cluster is deleted

Default value: false

mysql_storage_encrypted (string) optional

Set to true to keep the database contents encrypted

Default value: true

performance_insights_enabled (bool) optional

Set true to enable Performance Insights

Default value: false

primary_cluster_component (string) optional

If this cluster is a read replica and no replication source is explicitly given, the component name for the primary cluster

Default value: "aurora-mysql"

primary_cluster_region (string) optional

If this cluster is a read replica and no replication source is explicitly given, the region to look for a matching cluster

Default value: ""

publicly_accessible (bool) optional

Set to true to create the cluster in a public subnet

Default value: false

replication_source_identifier (string) optional

ARN of a source DB cluster or DB instance if this DB cluster is to be created as a Read Replica.
If this value is empty and replication is enabled, remote state will attempt to find
a matching cluster in the Primary DB Cluster's region

Default value: ""

ssm_password_source (string) optional

If var.ssm_passwords_enabled is true, DB user passwords will be retrieved from SSM using
var.ssm_password_source and the database username. If this value is not set,
a default path will be created using the SSM path prefix and ID of the associated Aurora Cluster.

Default value: ""

ssm_path_prefix (string) optional

SSM path prefix

Default value: "rds"

vpc_component_name (string) optional

The name of the VPC component

Default value: "vpc"

Context Variables

The following variables are defined in the context.tf file of this module and part of the terraform-null-label pattern.

additional_tag_map (map(string)) optional

Additional key-value pairs to add to each map in tags_as_list_of_maps. Not added to tags or id.
This is for some rare cases where resources want additional configuration of tags
and therefore take a list of maps with tag key, value, and additional configuration.

Required: No

Default value: { }

attributes (list(string)) optional

ID element. Additional attributes (e.g. workers or cluster) to add to id,
in the order they appear in the list. New attributes are appended to the
end of the list. The elements of the list are joined by the delimiter
and treated as a single ID element.

Required: No

Default value: [ ]

context (any) optional

Single object for setting entire context at once.
See description of individual variables for details.
Leave string and numeric variables as null to use default value.
Individual variable settings (non-null) override settings in context object,
except for attributes, tags, and additional_tag_map, which are merged.

Required: No

Default value:

{
  "additional_tag_map": {},
  "attributes": [],
  "delimiter": null,
  "descriptor_formats": {},
  "enabled": true,
  "environment": null,
  "id_length_limit": null,
  "label_key_case": null,
  "label_order": [],
  "label_value_case": null,
  "labels_as_tags": [
    "unset"
  ],
  "name": null,
  "namespace": null,
  "regex_replace_chars": null,
  "stage": null,
  "tags": {},
  "tenant": null
}

delimiter (string) optional

Delimiter to be used between ID elements.
Defaults to - (hyphen). Set to "" to use no delimiter at all.

Required: No

Default value: null

descriptor_formats (any) optional

Describe additional descriptors to be output in the descriptors output map.
Map of maps. Keys are names of descriptors. Values are maps of the form
\{<br/> format = string<br/> labels = list(string)<br/> \}
(Type is any so the map values can later be enhanced to provide additional options.)
format is a Terraform format string to be passed to the format() function.
labels is a list of labels, in order, to pass to format() function.
Label values will be normalized before being passed to format() so they will be
identical to how they appear in id.
Default is {} (descriptors output will be empty).

Required: No

Default value: { }

enabled (bool) optional

Set to false to prevent the module from creating any resources
Required: No

Default value: null

environment (string) optional

ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'
Required: No

Default value: null

id_length_limit (number) optional

Limit id to this many characters (minimum 6).
Set to 0 for unlimited length.
Set to null for keep the existing setting, which defaults to 0.
Does not affect id_full.

Required: No

Default value: null

label_key_case (string) optional

Controls the letter case of the tags keys (label names) for tags generated by this module.
Does not affect keys of tags passed in via the tags input.
Possible values: lower, title, upper.
Default value: title.

Required: No

Default value: null

label_order (list(string)) optional

The order in which the labels (ID elements) appear in the id.
Defaults to ["namespace", "environment", "stage", "name", "attributes"].
You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present.

Required: No

Default value: null

label_value_case (string) optional

Controls the letter case of ID elements (labels) as included in id,
set as tag values, and output by this module individually.
Does not affect values of tags passed in via the tags input.
Possible values: lower, title, upper and none (no transformation).
Set this to title and set delimiter to "" to yield Pascal Case IDs.
Default value: lower.

Required: No

Default value: null

labels_as_tags (set(string)) optional

Set of labels (ID elements) to include as tags in the tags output.
Default is to include all labels.
Tags with empty values will not be included in the tags output.
Set to [] to suppress all generated tags.
Notes:
The value of the name tag, if included, will be the id, not the name.
Unlike other null-label inputs, the initial setting of labels_as_tags cannot be
changed in later chained modules. Attempts to change it will be silently ignored.

Required: No

Default value:

[
  "default"
]

name (string) optional

ID element. Usually the component or solution name, e.g. 'app' or 'jenkins'.
This is the only ID element not also included as a tag.
The "name" tag is set to the full id string. There is no tag with the value of the name input.

Required: No

Default value: null

namespace (string) optional

ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique
Required: No

Default value: null

regex_replace_chars (string) optional

Terraform regular expression (regex) string.
Characters matching the regex will be removed from the ID elements.
If not set, "/[^a-zA-Z0-9-]/" is used to remove all characters other than hyphens, letters and digits.

Required: No

Default value: null

stage (string) optional

ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'
Required: No

Default value: null

tags (map(string)) optional

Additional tags (e.g. {'BusinessUnit': 'XYZ'}).
Neither the tag keys nor the tag values will be modified by this module.

Required: No

Default value: { }

tenant (string) optional

ID element (Rarely used, not included by default). A customer identifier, indicating who this instance of a resource is for
Required: No

Default value: null

Outputs

aurora_mysql_cluster_arn: The ARN of Aurora cluster
aurora_mysql_cluster_id: The ID of Aurora cluster
aurora_mysql_cluster_name: Aurora MySQL cluster identifier
aurora_mysql_endpoint: Aurora MySQL endpoint
aurora_mysql_master_hostname: Aurora MySQL DB master hostname
aurora_mysql_master_password: Location of admin password in SSM
aurora_mysql_master_password_ssm_key: SSM key for admin password
aurora_mysql_master_username: Aurora MySQL username for the master DB user
aurora_mysql_reader_endpoint: Aurora MySQL reader endpoint
aurora_mysql_replicas_hostname: Aurora MySQL replicas hostname
cluster_domain: Cluster DNS name
kms_key_arn: KMS key ARN for Aurora MySQL

Dependencies

Requirements

terraform, version: >= 1.0.0
aws, version: >= 4.0
random, version: >= 2.2

Providers

aws, version: >= 4.0
random, version: >= 2.2

Modules

Name	Version	Source	Description
`aurora_mysql`	1.3.1	`cloudposse/rds-cluster/aws`	n/a
`cluster`	0.25.0	`cloudposse/label/null`	n/a
`dns-delegated`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a
`eks`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a
`iam_roles`	latest	`../account-map/modules/iam-roles`	n/a
`kms_key_rds`	0.12.1	`cloudposse/kms-key/aws`	n/a
`parameter_store_write`	0.11.0	`cloudposse/ssm-parameter-store/aws`	n/a
`primary_cluster`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a
`this`	0.25.0	`cloudposse/label/null`	n/a
`vpc`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a
`vpc_ingress`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a

Resources

The following resources are used by this module:

random_password.mysql_admin_password (resource)
random_pet.mysql_admin_user (resource)
random_pet.mysql_db_name (resource)

Data Sources

The following data sources are used by this module:

aws_caller_identity.current (data source)
aws_iam_policy_document.kms_key_rds (data source)
aws_partition.current (data source)
aws_ssm_parameter.password (data source)

References

cloudposse/terraform-aws-components - Cloud Posse's upstream component

Usage​

Disaster Recovery with Cross-Region Replication​

Usage​

Promoting the Read Replica​

Variables​

Required Variables​

Optional Variables​

Context Variables​

Outputs​

Dependencies​

Requirements​

Providers​

Modules​

Resources​

Data Sources​

References​

Usage

Disaster Recovery with Cross-Region Replication

Usage

Promoting the Read Replica

Variables

Required Variables

Optional Variables

Context Variables

Outputs

Dependencies

Requirements

Providers

Modules

Resources

Data Sources

References