aurora-postgres-resources

This component is responsible for provisioning Aurora Postgres resources: additional databases, users, permissions, grants, etc.

Usage

Stack Level: Regional

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

components:
  terraform:
    aurora-postgres-resources:
      vars:
        aurora_postgres_component_name: aurora-postgres-example
        additional_users:
          example:
            db_user: example
            db_password: ""
            grants:
              - grant: ["ALL"]
                db: example
                object_type: database
                schema: ""

PostgreSQL Quick Reference on Grants

GRANTS can be on database, schema, role, table, and other database objects (e.g. columns in a table for fine control). Database and schema do not have much to grant. The object_type field in the input determines which kind of object the grant is being applied to. The db field is always required. The schema field is required unless the object_type is db, in which case it should be set to the empty string ("").

The keyword PUBLIC indicates that the privileges are to be granted to all roles, including those that might be created later. PUBLIC can be thought of as an implicitly defined group that always includes all roles. Any particular role will have the sum of privileges granted directly to it, privileges granted to any role it is presently a member of, and privileges granted to PUBLIC.

When an object is created, it is assigned an owner. The owner is normally the role that executed the creation statement. For most kinds of objects, the initial state is that only the owner (or a superuser) can do anything with the object. To allow other roles to use it, privileges must be granted. (When using AWS managed RDS, you cannot have access to any superuser roles; superuser is reserved for AWS to use to manage the cluster.)

PostgreSQL grants privileges on some types of objects to PUBLIC by default when the objects are created. No privileges are granted to PUBLIC by default on tables, table columns, sequences, foreign data wrappers, foreign servers, large objects, schemas, or tablespaces. For other types of objects, the default privileges granted to PUBLIC are as follows: CONNECT and TEMPORARY (create temporary tables) privileges for databases; EXECUTE privilege for functions and procedures; and USAGE privilege for languages and data types (including domains). The object owner can, of course, REVOKE both default and expressly granted privileges. (For maximum security, issue the REVOKE in the same transaction that creates the object; then there is no window in which another user can use the object.) Also, these default privilege settings can be overridden using the ALTER DEFAULT PRIVILEGES command.

The CREATE privilege:

For databases, allows new schemas and publications to be created within the database, and allows trusted extensions to be installed within the database.
For schemas, allows new objects to be created within the schema. To rename an existing object, you must own the object and have this privilege for the containing schema.

For databases and schemas, there are not a lot of other privileges to grant, and all but CREATE are granted by default, so you might as well grant "ALL". For tables etc., the creator has full control. You grant access to other users via explicit grants. This component does not allow fine-grained grants. You have to specify the database, and unless the grant is on the database, you have to specify the schema. For any other object type (table, sequence, function, procedure, routine, foreign_data_wrapper, foreign_server, column), the component applies the grants to all objects of that type in the specified schema.

Variables

Required Variables

region (string) required: AWS Region

Optional Variables

additional_databases (set(string)) optional

Additional databases to be created with the cluster

Default value: [ ]

additional_grants optional

Create additional database user with specified grants.
If var.ssm_password_source is set, passwords will be retrieved from SSM parameter store,
otherwise, passwords will be generated and stored in SSM parameter store under the service's key.

Type:

map(list(object({
grant : list(string)
db : string
})))

Default value: { }

additional_schemas optional

Create additional schemas for a given database.
If no database is given, the schema will use the database used by the provider configuration

Type:

map(object({
database : string
}))

Default value: { }

additional_users optional

Create additional database user for a service, specifying username, grants, and optional password.
If no password is specified, one will be generated. Username and password will be stored in
SSM parameter store under the service's key.

Type:

map(object({
db_user : string
db_password : string
grants : list(object({
  grant : list(string)
  db : string
  schema : string
  object_type : string
}))
}))

Default value: { }

admin_password (string) optional

postgresql password for the admin user

Default value: ""

aurora_postgres_component_name (string) optional

Aurora Postgres component name to read the remote state from

Default value: "aurora-postgres"

cluster_enabled (string) optional

Set to false to prevent the module from creating any resources

Default value: true

db_name (string) optional

Database name (default is not to create a database)

Default value: ""

read_passwords_from_ssm (bool) optional

When true, fetch user passwords from SSM

Default value: true

ssm_password_source (string) optional

If var.read_passwords_from_ssm 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: "aurora-postgres"

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

additional_databases: Additional databases
additional_grants: Additional grants
additional_schemas: Additional schemas
additional_users: Additional users

Dependencies

Requirements

terraform, version: >= 1.3.0
aws, version: >= 4.9.0
postgresql, version: >= 1.17.1

Providers

aws, version: >= 4.9.0
postgresql, version: >= 1.17.1

Modules

Name	Version	Source	Description
`additional_grants`	latest	`./modules/postgresql-user`	n/a
`additional_users`	latest	`./modules/postgresql-user`	n/a
`aurora_postgres`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a
`iam_roles`	latest	`../account-map/modules/iam-roles`	n/a
`this`	0.25.0	`cloudposse/label/null`	n/a

Resources

The following resources are used by this module:

postgresql_database.additional (resource)
postgresql_schema.additional (resource)

Data Sources

The following data sources are used by this module:

aws_ssm_parameter.admin_password (data source)
aws_ssm_parameter.password (data source)

References

cloudposse/terraform-aws-components - Cloud Posse's upstream component
PostgreSQL references (select the correct version of PostgreSQL at the top of the page):
- GRANT command
- Privileges that can be GRANTed

Usage​

PostgreSQL Quick Reference on Grants​

Variables​

Required Variables​

Optional Variables​

Context Variables​

Outputs​

Dependencies​

Requirements​

Providers​

Modules​

Resources​

Data Sources​

References​

Usage

PostgreSQL Quick Reference on Grants

Variables

Required Variables

Optional Variables

Context Variables

Outputs

Dependencies

Requirements

Providers

Modules

Resources

Data Sources

References