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Module: iam-policy

This terraform-aws-iam-policy module is a wrapper around the Terraform aws_iam_policy_document data source, enhancing it to provide multiple ways to create an AWS IAM Policy document (as a JSON string). It is primarily intended to simplify creating a policy in Terraform from external inputs. In particular, if you want to specify a policy in a tfvars file as a Terraform object, or in YAML as part of an Atmos stack (which is them turned into a Terraform object input), this module provides an object type declaration to use for the input and then it can make the translation to JSON for you. If you can supply the policy as JSON to begin with, or conveniently use the aws_iam_policy_document Terraform data source directly, then this module is not helpful in your case.

note

AWS's IAM policy document syntax allows for replacement of policy variables within a statement using ${...}-style notation, which conflicts with Terraform's interpolation syntax. In order to use AWS policy variables with this module, use &{...} notation for interpolations that should be processed by AWS rather than by Terraform. Nevertheless, any ${...}-style notations that appear in strings passed into this module (somehow escaping Terraform interpolation earlier) will be passed through to the policy document unchanged.

Usage​

For a complete example, see examples/complete.

For automated tests of the complete example using bats and Terratest (which tests and deploys the example on AWS), see test.

module "iam_policy" {
  source  = "cloudposse/iam-policy/aws"
  # Cloud Posse recommends pinning every module to a specific version
  # version = "x.x.x"

  iam_policy = [{
    version = "2012-10-17"
    policy_id = "example"
    statements = [
      {
        sid       = "ListMyBucket"
        effect    = "Allow"
        actions   = ["s3:ListBucket"]
        resources = ["arn:aws:s3:::test"]
        conditions = [
          {
            test     = "StringLike"
            variable = "cloudwatch:namespace"
            values   = ["x-*"]
          },
        ]
      },
      {
        sid       = "WriteMyBucket"
        effect    = "Allow"
        actions   = ["s3:PutObject", "s3:GetObject", "s3:DeleteObject"]
        resources = ["arn:aws:s3:::test/*"]
        conditions = [
          {
            test     = "StringLike"
            variable = "cloudwatch:namespace"
            values   = ["x-*"]
          },
        ]
      }
    ]
  }]

data "aws_iam_policy_document" "assume_role" {
  statement {
    actions = ["sts:AssumeRole"]

    principals {
      type        = "Service"
      identifiers = ["ec2.amazonaws.com"]
    }
  }
}

resource "aws_iam_role" "example" {
  name               = "hello_role"
  assume_role_policy = data.aws_iam_policy_document.assume_role.json

  inline_policy {
    name = "test_policy"

    policy = module.iam_policy.json
  }
}

Examples​

Here is an example of using this module:

Variables​

Required Variables​

Optional Variables​

description (string) optional

Description of created IAM policy


Default value: null

iam_override_policy_documents (list(string)) optional

List of IAM policy documents (as JSON strings) that are merged together into the exported document with higher precedence.
In merging, statements with non-blank SIDs will override statements with the same SID
from earlier documents in the list and from other "source" documents.



Default value: null

iam_policy optional

IAM policy as list of Terraform objects, compatible with Terraform aws_iam_policy_document data source
except that source_policy_documents and override_policy_documents are not included.
Use inputs iam_source_policy_documents and iam_override_policy_documents for that.



Type:

list(object({
policy_id = optional(string, null)
version   = optional(string, null)
statements = list(object({
  sid           = optional(string, null)
  effect        = optional(string, null)
  actions       = optional(list(string), null)
  not_actions   = optional(list(string), null)
  resources     = optional(list(string), null)
  not_resources = optional(list(string), null)
  conditions = optional(list(object({
    test     = string
    variable = string
    values   = list(string)
  })), [])
  principals = optional(list(object({
    type        = string
    identifiers = list(string)
  })), [])
  not_principals = optional(list(object({
    type        = string
    identifiers = list(string)
  })), [])
}))
}))

Default value: [ ]

iam_policy_enabled (bool) optional

Whether to create the IAM managed policy in AWS or not.
If false without role_names, it will output the JSON policy,
with role_names, it will attach the inline policy.



Default value: false

iam_policy_id (string) optional

Deprecated: Use iam_policy instead: ID for the policy document when using iam_policy_statements.


Default value: null

iam_policy_statements (any) optional

Deprecated: Use iam_policy instead.
List or Map of IAM policy statements to use in the policy.
This can be used with iam_source_policy_documents and iam_override_policy_documents
and with or instead of iam_source_json_url.



Default value: [ ]

iam_source_json_url (string) optional

URL of the IAM policy (in JSON format) to download and use as source_json argument.
This is useful when using a 3rd party service that provides their own policy.
Statements in this policy will be overridden by statements with the same SID in iam_override_policy_documents.



Default value: null

iam_source_policy_documents (list(string)) optional

List of IAM policy documents (as JSON strings) that are merged together into the exported document.
Statements defined in iam_source_policy_documents must have unique SIDs and be distinct from SIDs
in iam_policy and deprecated iam_policy_statements.
Statements in these documents will be overridden by statements with the same SID in iam_override_policy_documents.



Default value: null

role_names (list(string)) optional

IAM role names to attach the policy to. Use iam_policy_enabled to toggle between managed or inline.



Default value: 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​

json

JSON body of the IAM policy document

policy_arn

ARN of created IAM policy

Dependencies​

Requirements​

  • terraform, version: >= 1.3.0
  • aws, version: >= 4.0
  • http, version: >= 3.0

Providers​

  • aws, version: >= 4.0
  • http, version: >= 3.0

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: