Component: `aurora-postgres`

This component is responsible for provisioning Aurora Postgres 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-postgres/defaults.yaml file (base component for all Aurora Postgres clusters with default settings):

components:
  terraform:
    aurora-postgres/defaults:
      metadata:
        type: abstract
      vars:
        enabled: true
        name: aurora-postgres
        tags:
          Team: sre
          Service: aurora-postgres
        cluster_name: shared
        deletion_protection: false
        storage_encrypted: true
        engine: aurora-postgresql

        # Provisioned configuration
        engine_mode: provisioned
        engine_version: "15.3"
        cluster_family: aurora-postgresql15
        # 1 writer, 1 reader
        cluster_size: 2
        # https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Concepts.DBInstanceClass.html
        instance_type: db.t3.medium

        admin_user: postgres
        admin_password: "" # generate random password
        database_name: postgres
        database_port: 5432
        skip_final_snapshot: false
        # Enhanced Monitoring
        # A boolean flag to enable/disable the creation of the enhanced monitoring IAM role.
        # If set to false, the module will not create a new role and will use rds_monitoring_role_arn for enhanced monitoring
        enhanced_monitoring_role_enabled: true
        # The interval, in seconds, between points when enhanced monitoring metrics are collected for the DB instance.
        # To disable collecting Enhanced Monitoring metrics, specify 0. The default is 0. Valid Values: 0, 1, 5, 10, 15, 30, 60
        rds_monitoring_interval: 15
        # Allow ingress from the following accounts
        # If any of tenant, stage, or environment aren't given, this will be taken
        allow_ingress_from_vpc_accounts:
          - tenant: core
            stage: auto

Example (not actual):

stacks/uw2-dev.yaml file (override the default settings for the cluster in the dev account, create an additional database and user):

import:
  - catalog/aurora-postgres/defaults

components:
  terraform:
    aurora-postgres:
      metadata:
        component: aurora-postgres
        inherits:
          - aurora-postgres/defaults
      vars:
        enabled: true

Finding Aurora Engine Version

Use the following to query the AWS API by engine-mode. Both provisioned and Serverless v2 use the privisoned engine mode, whereas only Serverless v1 uses the serverless engine mode.

aws rds describe-db-engine-versions \
  --engine aurora-postgresql \
  --query 'DBEngineVersions[].EngineVersion' \
  --filters 'Name=engine-mode,Values=serverless'

Use the following to query AWS API by db-instance-class. Use this query to find supported versions for a specific instance class, such as db.serverless with Serverless v2.

aws rds describe-orderable-db-instance-options \
  --engine aurora-postgresql \
  --db-instance-class db.serverless \
  --query 'OrderableDBInstanceOptions[].[EngineVersion]'

Once a version has been selected, use the following to find the cluster family.

aws rds describe-db-engine-versions --engine aurora-postgresql --query "DBEngineVersions[]" | \
jq '.[] | select(.EngineVersion == "15.3") |
   { Engine: .Engine, EngineVersion: .EngineVersion, DBParameterGroupFamily: .DBParameterGroupFamily }'

Examples

Generally there are three different engine configurations for Aurora: provisioned, Serverless v1, and Serverless v2.

Provisioned Aurora Postgres

See the default usage example above

Serverless v1 Aurora Postgres

Serverless v1 requires engine-mode set to serverless uses scaling_configuration to configure scaling options.

For valid values, see ModifyCurrentDBClusterCapacity.

components:
  terraform:
    aurora-postgres:
      vars:
        enabled: true
        name: aurora-postgres
        eks_component_names:
          - eks/cluster
        allow_ingress_from_vpc_accounts:
          # Allows Spacelift
          - tenant: core
            stage: auto
            environment: use2
          # Allows VPN
          - tenant: core
            stage: network
            environment: use2
        cluster_name: shared
        engine: aurora-postgresql

        # Serverless v1 configuration
        engine_mode: serverless
        instance_type: "" # serverless engine_mode ignores `var.instance_type`
        engine_version: "13.9" # Latest supported version as of 08/28/2023
        cluster_family: aurora-postgresql13
        cluster_size: 0 # serverless
        scaling_configuration:
          - auto_pause: true
            max_capacity: 5
            min_capacity: 2
            seconds_until_auto_pause: 300
            timeout_action: null

        admin_user: postgres
        admin_password: "" # generate random password
        database_name: postgres
        database_port: 5432
        storage_encrypted: true
        deletion_protection: true
        skip_final_snapshot: false
        # Creating read-only users or additional databases requires Spacelift
        read_only_users_enabled: false
        # Enhanced Monitoring
        # A boolean flag to enable/disable the creation of the enhanced monitoring IAM role.
        # If set to false, the module will not create a new role and will use rds_monitoring_role_arn for enhanced monitoring
        enhanced_monitoring_role_enabled: true
        enhanced_monitoring_attributes: ["monitoring"]
        # The interval, in seconds, between points when enhanced monitoring metrics are collected for the DB instance.
        # To disable collecting Enhanced Monitoring metrics, specify 0. The default is 0. Valid Values: 0, 1, 5, 10, 15, 30, 60
        rds_monitoring_interval: 15
        iam_database_authentication_enabled: false
        additional_users: {}

Serverless v2 Aurora Postgres

Aurora Postgres Serverless v2 uses the provisioned engine mode with db.serverless instances. In order to configure scaling with Serverless v2, use var.serverlessv2_scaling_configuration.

For more on valid scaling configurations, see Performance and scaling for Aurora Serverless v2.

components:
  terraform:
    aurora-postgres:
      vars:
        enabled: true
        name: aurora-postgres
        eks_component_names:
          - eks/cluster
        allow_ingress_from_vpc_accounts:
          # Allows Spacelift
          - tenant: core
            stage: auto
            environment: use2
          # Allows VPN
          - tenant: core
            stage: network
            environment: use2
        cluster_name: shared
        engine: aurora-postgresql

        # Serverless v2 configuration
        engine_mode: provisioned
        instance_type: "db.serverless"
        engine_version: "15.3"
        cluster_family: aurora-postgresql15
        cluster_size: 2
        serverlessv2_scaling_configuration:
          min_capacity: 2
          max_capacity: 64

        admin_user: postgres
        admin_password: "" # generate random password
        database_name: postgres
        database_port: 5432
        storage_encrypted: true
        deletion_protection: true
        skip_final_snapshot: false
        # Creating read-only users or additional databases requires Spacelift
        read_only_users_enabled: false
        # Enhanced Monitoring
        # A boolean flag to enable/disable the creation of the enhanced monitoring IAM role.
        # If set to false, the module will not create a new role and will use rds_monitoring_role_arn for enhanced monitoring
        enhanced_monitoring_role_enabled: true
        enhanced_monitoring_attributes: ["monitoring"]
        # The interval, in seconds, between points when enhanced monitoring metrics are collected for the DB instance.
        # To disable collecting Enhanced Monitoring metrics, specify 0. The default is 0. Valid Values: 0, 1, 5, 10, 15, 30, 60
        rds_monitoring_interval: 15
        iam_database_authentication_enabled: false
        additional_users: {}

Requirements

Name	Version
terraform	>= 1.3.0
aws	>= 4.9.0
postgresql	>= 1.17.1
random	>= 2.3

Providers

Name	Version
aws	>= 4.9.0
random	>= 2.3

Modules

Name	Source	Version
aurora_postgres_cluster	cloudposse/rds-cluster/aws	1.3.2
cluster	cloudposse/label/null	0.25.0
dns_gbl_delegated	cloudposse/stack-config/yaml//modules/remote-state	1.5.0
eks	cloudposse/stack-config/yaml//modules/remote-state	1.5.0
iam_roles	../account-map/modules/iam-roles	n/a
kms_key_rds	cloudposse/kms-key/aws	0.12.1
parameter_store_write	cloudposse/ssm-parameter-store/aws	0.11.0
this	cloudposse/label/null	0.25.0
vpc	cloudposse/stack-config/yaml//modules/remote-state	1.5.0
vpc_ingress	cloudposse/stack-config/yaml//modules/remote-state	1.5.0

Resources

Name	Type
random_password.admin_password	resource
random_pet.admin_user	resource
random_pet.database_name	resource
aws_caller_identity.current	data source
aws_iam_policy_document.kms_key_rds	data source
aws_partition.current	data source

Inputs

Name	Description	Type	Default	Required
additional_tag_map	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.	`map(string)`	`{}`	no
admin_password	Postgres password for the admin user	`string`	`""`	no
admin_user	Postgres admin user name	`string`	`""`	no
allow_ingress_from_vpc_accounts	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	`list(object({ vpc = optional(string, "vpc") environment = optional(string) stage = optional(string) tenant = optional(string) }))`	`[]`	no
allow_major_version_upgrade	Enable to allow major engine version upgrades when changing engine versions. Defaults to false.	`bool`	`false`	no
allowed_cidr_blocks	List of CIDRs allowed to access the database (in addition to security groups and subnets)	`list(string)`	`[]`	no
attributes	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.	`list(string)`	`[]`	no
autoscaling_enabled	Whether to enable cluster autoscaling	`bool`	`false`	no
autoscaling_max_capacity	Maximum number of instances to be maintained by the autoscaler	`number`	`5`	no
autoscaling_min_capacity	Minimum number of instances to be maintained by the autoscaler	`number`	`1`	no
autoscaling_policy_type	Autoscaling policy type. `TargetTrackingScaling` and `StepScaling` are supported	`string`	`"TargetTrackingScaling"`	no
autoscaling_scale_in_cooldown	The amount of time, in seconds, after a scaling activity completes and before the next scaling down activity can start. Default is 300s	`number`	`300`	no
autoscaling_scale_out_cooldown	The amount of time, in seconds, after a scaling activity completes and before the next scaling up activity can start. Default is 300s	`number`	`300`	no
autoscaling_target_metrics	The metrics type to use. If this value isn't provided the default is CPU utilization	`string`	`"RDSReaderAverageCPUUtilization"`	no
autoscaling_target_value	The target value to scale with respect to target metrics	`number`	`75`	no
ca_cert_identifier	The identifier of the CA certificate for the DB instance	`string`	`null`	no
cluster_dns_name_part	Part of DNS name added to module and cluster name for DNS for cluster endpoint	`string`	`"writer"`	no
cluster_family	Family of the DB parameter group. Valid values for Aurora PostgreSQL: `aurora-postgresql9.6`, `aurora-postgresql10`, `aurora-postgresql11`, `aurora-postgresql12`	`string`	`"aurora-postgresql13"`	no
cluster_name	Short name for this cluster	`string`	n/a	yes
cluster_size	Postgres cluster size	`number`	n/a	yes
context	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.	`any`	`{ "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 }`	no
database_name	Name for an automatically created database on cluster creation. An empty name will generate a db name.	`string`	`""`	no
database_port	Database port	`number`	`5432`	no
deletion_protection	Specifies whether the Cluster should have deletion protection enabled. The database can't be deleted when this value is set to `true`	`bool`	`false`	no
delimiter	Delimiter to be used between ID elements. Defaults to `-` (hyphen). Set to `""` to use no delimiter at all.	`string`	`null`	no
descriptor_formats	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).	`any`	`{}`	no
dns_gbl_delegated_environment_name	The name of the environment where global `dns_delegated` is provisioned	`string`	`"gbl"`	no
eks_component_names	The names of the eks components	`set(string)`	`[ "eks/cluster" ]`	no
eks_security_group_enabled	Use the eks default security group	`bool`	`false`	no
enabled	Set to false to prevent the module from creating any resources	`bool`	`null`	no
enabled_cloudwatch_logs_exports	List of log types to export to cloudwatch. The following log types are supported: audit, error, general, slowquery	`list(string)`	`[]`	no
engine	Name of the database engine to be used for the DB cluster	`string`	`"postgresql"`	no
engine_mode	The database engine mode. Valid values: `global`, `multimaster`, `parallelquery`, `provisioned`, `serverless`	`string`	n/a	yes
engine_version	Engine version of the Aurora global database	`string`	`"13.4"`	no
enhanced_monitoring_attributes	Attributes used to format the Enhanced Monitoring IAM role. If this role hits IAM role length restrictions (max 64 characters), consider shortening these strings.	`list(string)`	`[ "enhanced-monitoring" ]`	no
enhanced_monitoring_role_enabled	A boolean flag to enable/disable the creation of the enhanced monitoring IAM role. If set to `false`, the module will not create a new role and will use `rds_monitoring_role_arn` for enhanced monitoring	`bool`	`true`	no
environment	ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'	`string`	`null`	no
iam_database_authentication_enabled	Specifies whether or mappings of AWS Identity and Access Management (IAM) accounts to database accounts is enabled	`bool`	`false`	no
id_length_limit	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`.	`number`	`null`	no
instance_type	EC2 instance type for Postgres cluster	`string`	n/a	yes
intra_security_group_traffic_enabled	Whether to allow traffic between resources inside the database's security group.	`bool`	`false`	no
label_key_case	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`.	`string`	`null`	no
label_order	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.	`list(string)`	`null`	no
label_value_case	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`.	`string`	`null`	no
labels_as_tags	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.	`set(string)`	`[ "default" ]`	no
maintenance_window	Weekly time range during which system maintenance can occur, in UTC	`string`	`"wed:03:00-wed:04:00"`	no
name	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.	`string`	`null`	no
namespace	ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique	`string`	`null`	no
performance_insights_enabled	Whether to enable Performance Insights	`bool`	`false`	no
publicly_accessible	Set true to make this database accessible from the public internet	`bool`	`false`	no
rds_monitoring_interval	The interval, in seconds, between points when enhanced monitoring metrics are collected for the DB instance. To disable collecting Enhanced Monitoring metrics, specify 0. The default is 0. Valid Values: 0, 1, 5, 10, 15, 30, 60	`number`	`60`	no
reader_dns_name_part	Part of DNS name added to module and cluster name for DNS for cluster reader	`string`	`"reader"`	no
regex_replace_chars	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.	`string`	`null`	no
region	AWS Region	`string`	n/a	yes
scaling_configuration	List of nested attributes with scaling properties. Only valid when `engine_mode` is set to `serverless`. This is required for Serverless v1	`list(object({ auto_pause = bool max_capacity = number min_capacity = number seconds_until_auto_pause = number timeout_action = string }))`	`[]`	no
serverlessv2_scaling_configuration	Nested attribute with scaling properties for ServerlessV2. Only valid when `engine_mode` is set to `provisioned.` This is required for Serverless v2	`object({ min_capacity = number max_capacity = number })`	`null`	no
skip_final_snapshot	Normally AWS makes a snapshot of the database before deleting it. Set this to `true` in order to skip this. NOTE: The final snapshot has a name derived from the cluster name. If you delete a cluster, get a final snapshot, then create a cluster of the same name, its final snapshot will fail with a name collision unless you delete the previous final snapshot first.	`bool`	`false`	no
snapshot_identifier	Specifies whether or not to create this cluster from a snapshot	`string`	`null`	no
ssm_path_prefix	Top level SSM path prefix (without leading or trailing slash)	`string`	`"aurora-postgres"`	no
stage	ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'	`string`	`null`	no
storage_encrypted	Specifies whether the DB cluster is encrypted	`bool`	`true`	no
tags	Additional tags (e.g. `{'BusinessUnit': 'XYZ'}`). Neither the tag keys nor the tag values will be modified by this module.	`map(string)`	`{}`	no
tenant	ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for	`string`	`null`	no
vpc_component_name	The name of the VPC component	`string`	`"vpc"`	no

Outputs

Name	Description
admin_username	Postgres admin username
cluster_identifier	Postgres cluster identifier
config_map	Map containing information pertinent to a PostgreSQL client configuration.
database_name	Postgres database name
kms_key_arn	KMS key ARN for Aurora Postgres
master_hostname	Postgres master hostname
replicas_hostname	Postgres replicas hostname
ssm_key_paths	Names (key paths) of all SSM parameters stored for this cluster

References

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

Component: aurora-postgres

Usage​

Finding Aurora Engine Version​

Examples​

Provisioned Aurora Postgres​

Serverless v1 Aurora Postgres​

Serverless v2 Aurora Postgres​

Requirements​

Providers​

Modules​

Resources​

Inputs​

Outputs​

References​