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aws-team-roles

This component is responsible for provisioning user and system IAM roles outside the identity account. It sets them up to be assumed from the "team" roles defined in the identity account by the aws-teams component and/or the AWS SSO permission sets defined in the aws-sso component, and/or be directly accessible via SAML logins.

Privileges are Granted to Users via IAM Policies​

Each role is granted permissions by attaching a list of IAM policies to the IAM role via its role_policy_arns list. You can configure AWS managed policies by entering the ARNs of the policies directly into the list, or you can create a custom policy as follows:

  1. Give the policy a name, e.g. eks-admin. We will use NAME as a placeholder for the name in the instructions below.

  2. Create a file in the aws-teams directory with the name policy-NAME.tf.

  3. In that file, create a policy as follows:

    data "aws_iam_policy_document" "NAME" {
      # Define the policy here
    }

    resource "aws_iam_policy" "NAME" {
      name   = format("%s-NAME", module.this.id)
      policy = data.aws_iam_policy_document.NAME.json

      tags = module.this.tags
    }

  4. Create a file named additional-policy-map_override.tf in the aws-team-roles directory (if it does not already exist). This is a terraform override file, meaning its contents will be merged with the main terraform file, and any locals defined in it will override locals defined in other files. Having your code in this separate override file makes it possible for the component to provide a placeholder local variable so that it works without customization, while allowing you to customize the component and still update it without losing your customizations.

  5. In that file, redefine the local variable overridable_additional_custom_policy_map map as follows:

    locals {
      overridable_additional_custom_policy_map = {
        NAME = aws_iam_policy.NAME.arn
      }
    }

    If you have multiple custom policies, add each one to the map in the form NAME = aws_iam_policy.NAME.arn.

  6. With that done, you can now attach that policy by adding the name to the role_policy_arns list. For example:

    role_policy_arns:
      - "arn:aws:iam::aws:policy/job-function/ViewOnlyAccess"
      - "NAME"

Usage​

Stack Level: Global

Deployment: Must be deployed by SuperAdmin using atmos CLI

Here's an example snippet for how to use this component. This specific usage is an example only, and not intended for production use. You set the defaults in one YAML file, and import that file into each account's Global stack (except for the identity account itself). If desired, you can make account-specific changes by overriding settings, for example

  • Disable entire roles in the account by setting enabled: false
  • Limit who can access the role by setting a different value for trusted_teams
  • Change the permissions available to that role by overriding the role_policy_arns (not recommended, limit access to the role or create a different role with the desired set of permissions instead).

Note that when overriding, maps are deep merged, but lists are replaced. This means, for example, that your setting of trusted_primary_roles in an override completely replaces the default, it does not add to it, so if you want to allow an extra "primary" role to have access to the role, you have to include all the default "primary" roles in the list, too, or they will lose access.

components:
  terraform:
    aws-team-roles:
      backend:
        s3:
          # Override the default Role for accessing the backend, because SuperAdmin is not allowed to assume that role
          role_arn: null
      vars:
        enabled: true
        roles:
          # `template` serves as the default configuration for other roles via the YAML anchor.
          # However, `atmos` does not support "import" of YAML anchors, so if you define a new role
          # in another file, you will not be able to reference this anchor.
          template: &user-template # If `enabled: false`, the role will not be created in this account
            enabled: false

            # `max_session_duration` set the maximum session duration (in seconds) for the IAM roles.
            # This setting can have a value from 3600 (1 hour) to 43200 (12 hours).
            # For roles people log into via SAML, a long duration is convenient to prevent them
            # from having to frequently re-authenticate.
            # For roles assumed from some other role, the setting is practically irrelevant, because
            # the AssumeRole API limits the duration to 1 hour in any case.
            # References:
            # - https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_use.html
            # - https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html
            max_session_duration: 3600 # 1 hour in seconds

            # role_policy_arns are the IAM Policy ARNs to attach to this policy. In addition to real ARNs,
            # you can use keys in the `custom_policy_map` in `main.tf` to select policies defined in the component.
            # If you are using keys from the map, plans look better if you put them after the real role ARNs.
            role_policy_arns: []
            role_description: "Template role, should not exist"

            # If `aws_saml_login_enabled: true` then the role will be available via SAML logins,
            # but only via the SAML IDPs configured for this account.
            # Otherwise, it will only be accessible via `assume role`.
            aws_saml_login_enabled: false

            ## The following attributes control access to this role via `assume role`.
            ## `trusted_*` grants access, `denied_*` denies access.
            ## If a role is both trusted and denied, it will not be able to access this role.

            # Permission sets specify users operating from the given AWS SSO permission set in this account.
            trusted_permission_sets: []
            denied_permission_sets: []

            # Primary roles specify the short role names of roles in the primary (identity)
            # account that are allowed to assume this role.
            # BE CAREFUL: This is setting the default access for other roles.
            trusted_teams: []
            denied_teams: []

            # Role ARNs specify Role ARNs in any account that are allowed to assume this role.
            # BE CAREFUL: there is nothing limiting these Role ARNs to roles within our organization.
            trusted_role_arns: []
            denied_role_arns: []

          ##
          ## admin and terraform are the core team roles
          ##

          admin:
            <<: *user-template
            enabled: true
            role_policy_arns:
              - "arn:aws:iam::aws:policy/AdministratorAccess"
            role_description: "Full administration of this account"
            trusted_teams: ["admin"]

          terraform:
            <<: *user-template
            enabled: true
            # We require Terraform to be allowed to create and modify IAM roles
            # and policies (e.g. for EKS service accounts), so there is no use trying to restrict it.
            # For better security, we could segregate components that needed
            # administrative permissions and use a more restrictive role
            # for Terraform, such as PowerUser (further restricted to deny AWS SSO changes).
            role_policy_arns:
              - "arn:aws:iam::aws:policy/AdministratorAccess"
            role_description: "Role for Terraform administration of this account"
            trusted_teams: ["admin", "spacelift"]

Variables​

Required Variables​

region (string) required

AWS Region

roles required

A map of roles to configure the accounts.

Type:

map(object({
enabled = bool

denied_teams            = list(string)
denied_permission_sets  = list(string)
denied_role_arns        = list(string)
max_session_duration    = number # in seconds 3600 <= max <= 43200 (12 hours)
role_description        = string
role_policy_arns        = list(string)
aws_saml_login_enabled  = bool
trusted_teams           = list(string)
trusted_permission_sets = list(string)
trusted_role_arns       = list(string)
}))

Optional Variables​

import_role_arn (string) optional

IAM Role ARN to use when importing a resource


Default value: null

trusted_github_repos (map(list(string))) optional

Map where keys are role names (same keys as roles) and values are lists of
GitHub repositories allowed to assume those roles. See account-map/modules/github-assume-role-policy.mixin.tf
for specifics about repository designations.



Default value: { }

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​

role_name_role_arn_map

Map of role names to role ARNs

Dependencies​

Requirements​

  • terraform, version: >= 1.0.0
  • aws, version: >= 4.9.0
  • local, version: >= 1.3

Providers​

  • aws, version: >= 4.9.0
  • local, version: >= 1.3

Modules​

NameVersionSourceDescription
assume_rolelatest../account-map/modules/team-assume-role-policyn/a
aws_saml1.5.0cloudposse/stack-config/yaml//modules/remote-staten/a
iam_roleslatest../account-map/modules/iam-rolesn/a
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:

References​