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Module: ssm-tls-self-signed-cert

This module creates a self-signed certificate and writes it alongside with its key to SSM Parameter Store (or alternatively AWS Secrets Manager).

Usage​

For a complete example, see examples/complete.

module "self_signed_cert" {
  source = "cloudposse/ssm-tls-self-signed-cert/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version = "x.x.x"

  namespace = "eg"
  stage     = "dev"
  name      = "self-signed-cert"

  subject = {
    common_name         = "example"
    organization        = "Cloud Posse"
    organizational_unit = "Engineering"
  }

  validity = {
    duration_hours      = 730
    early_renewal_hours = 24
  }

  allowed_uses = [
    "key_encipherment",
    "digital_signature",
    "server_auth"
  ]

  subject_alt_names = {
    ip_addresses = ["10.10.10.10"]
    dns_names    = ["example.com"]
    uris         = ["https://example.com"]
  }
}

Examples​

Here is an example of using this module:

Variables​

Required Variables​

allowed_uses (list(string)) required

List of keywords each describing a use that is permitted for the issued certificate.
Must be one of of the values outlined in self_signed_cert.allowed_uses.


Optional Variables​

asm_recovery_window_in_days (number) optional

Number of days that AWS Secrets Manager waits before it can delete the secret. This value can be 0 to force deletion without recovery or range from 7 to 30 days.


This value is ignored if var.certificate_backends is not ASM, or if var.certificate_backend_enabled is false.



Default value: 30

basic_constraints optional

The basic constraints of the issued certificate.
Currently, only the CA constraint (which identifies whether the subject of the certificate is a CA) can be set.


Defaults to this certificate not being a CA.



Type:

object({
ca = bool
})

Default value:

{
  "ca": false
}
certificate_backend_kms_key_id (string) optional

The KMD Key ID (ARN or ID) to use when encrypting either the AWS SSM Parameters or AWS Secrets Manager Secrets relating to the certificate.


If not specified, the Amazon-managed Key alias/aws/ssm will be used if var.certificate_backends contains SSM,
and alias/aws/secretsmanager will be used if var.certificate_backends is ASM.



Default value: null

certificate_backends (set(string)) optional

The certificate backend to use when writing secrets related to the self-signed certificate.
The value specified can either be SSM (AWS Systems Manager Parameter Store), ASM (AWS Secrets Manager),
and/or ACM (AWS Certificate Manager).


Defaults to SSM.



Default value:

[
  "SSM"
]
certificate_backends_base64_enabled (bool) optional

Enable or disable base64 encoding of secrets before writing them to the secrets store.


Default value: false

certificate_backends_enabled (bool) optional

Enable or disable writing to the secrets store.


Default value: true

certificate_chain optional

When using ACM as a certificate backend, some certificates store a certificate chain from a CA. This CA will come from another resource.



Type:

object({
cert_pem        = string
private_key_pem = string
})

Default value: null

private_key_algorithm (string) optional

The name of the algorithm for the private key of the certificate. Currently only RSA and ECDSA are supported.


If a preexisting private key is supplied via var.private_key_contents, this value must match that key's algorithm.


Defaults to RSA as it is a more widely adopted algorithm, although ECDSA provides the same level of security and with shorter keys.



Default value: "RSA"

private_key_contents (string) optional

The contents of the private key to use for the certificate.
If supplied, this module will not create a private key and use these contents instead for the private key.


Defaults to null, which means a private key will be created.



Default value: null

private_key_ecdsa_curve (string) optional

When var.cert_key_algorithm is ECDSA, the name of the elliptic curve to use. May be any one of P224, P256, P384 or P521.


Ignored if var.cert_key_algorithm is not ECDSA, or if a preexisting private key is supplied via var.private_key_contents.


Defaults to the tls provider default.



Default value: "P224"

private_key_rsa_bits (number) optional

When var.cert_key_algorithm is RSA, the size of the generated RSA key in bits.


Ignored if var.cert_key_algorithm is not RSA, or if a preexisting private key is supplied via var.private_key_contents.


Defaults to the tls provider default.



Default value: 2048

secret_extensions optional

The extensions use when writing secrets to the certificate backend.


Please refer to var.secret_path_format for information on how secret paths are computed.



Type:

object({
certificate = string
private_key = string
})

Default value:

{
  "certificate": "pem",
  "private_key": "key"
}
secret_path_format (string) optional

The path format to use when writing secrets to the certificate backend.


The certificate secret path will be computed as format(var.secret_path_format, var.name, var.secret_extensions.certificate)
and the private key path as format(var.secret_path_format, var.name, var.secret_extensions.private_key).


Thus by default, if var.name=example-self-signed-cert, then the resulting secret paths for the self-signed certificate's
PEM file and private key will be /example-self-signed-cert.pem and /example-self-signed-cert.key, respectively.


This variable can be overridden in order to create more specific certificate backend paths.



Default value: "/%s.%s"

skid_enabled (bool) optional

Whether or not the subject key identifier (SKID) should be included in the certificate.


Default value: false

subject (any) optional

The subject configuration for the certificate.
This should be a map that is compatible with tls_cert_request.subject.


If common_name is omitted, it will be set as module.this.id.



Default value: { }

subject_alt_names optional

The subject alternative name (SAN) configuration for the certificate. This configuration consists of several lists, each of which can also be set to null or [].


dns_names: List of DNS names for which a certificate is being requested.
ip_addresses: List of IP addresses for which a certificate is being requested.
uris: List of URIs for which a certificate is being requested.


Defaults to no SANs.



Type:

object({
dns_names    = list(string)
ip_addresses = list(string)
uris         = list(string)
})

Default value:

{
  "dns_names": null,
  "ip_addresses": null,
  "uris": null
}
use_locally_signed (bool) optional

Create a locally signed certificate/key pair instead of a self-signed one. This is useful it a previously created certificate chain is to be used to sign a certificate.



Default value: false

validity optional

Validity settings for the issued certificate:


duration_hours: The number of hours from issuing the certificate until it becomes invalid.
early_renewal_hours: If set, the resource will consider the certificate to have expired the given number of hours before its actual expiry time (see: self_signed_cert.early_renewal_hours).


Defaults to 10 years and no early renewal hours.



Type:

object({
duration_hours      = number
early_renewal_hours = number
})

Default value:

{
  "duration_hours": 87600,
  "early_renewal_hours": null
}

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​

certificate_arn

ARN of certificate stored in ACM that other services may need to refer to. This is useful when the certificate is stored in ACM.

certificate_key_path

Secrets store path containing the certificate private key file.

certificate_pem

Contents of the certificate PEM.

certificate_pem_path

Secrets store path containing the certificate PEM file.

Dependencies​

Requirements​

  • terraform, version: >= 0.13.0
  • aws, version: >= 3.0
  • tls, version: >= 4.0.0

Providers​

  • aws, version: >= 3.0
  • tls, version: >= 4.0.0

Modules​

NameVersionSourceDescription
this0.25.0cloudposse/label/nulln/a

Resources​

The following resources are used by this module:

Data Sources​

The following data sources are used by this module: