github-oidc-role

This component is responsible for creating IAM roles for GitHub Actions to assume.

Usage

Stack Level: Global

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

# stacks/catalog/github-oidc-role/defaults.yaml
components:
  terraform:
    github-oidc-role/defaults:
      metadata:
        type: abstract
      vars:
        enabled: true
        name: gha-iam
        # Note: inherited lists are not merged, they are replaced
        github_actions_allowed_repos:
          - MyOrg/* ## allow all repos in MyOrg

Example using for gitops (predefined policy):

# stacks/catalog/github-oidc-role/gitops.yaml
import:
  - catalog/github-oidc-role/defaults

components:
  terraform:
    github-oidc-role/gitops:
      metadata:
        component: github-oidc-role
        inherits:
          - github-oidc-role/defaults
      vars:
        enabled: true
        # Note: inherited lists are not merged, they are replaced
        github_actions_allowed_repos:
          - "MyOrg/infrastructure"
        attributes: ["gitops"]
        iam_policies:
          - gitops
        gitops_policy_configuration:
          s3_bucket_component_name: gitops/s3-bucket
          dynamodb_component_name: gitops/dynamodb

Example using for lambda-cicd (predefined policy):

# stacks/catalog/github-oidc-role/lambda-cicd.yaml
import:
  - catalog/github-oidc-role/defaults

components:
  terraform:
    github-oidc-role/lambda-cicd:
      metadata:
        component: github-oidc-role
        inherits:
          - github-oidc-role/defaults
      vars:
        enabled: true
        github_actions_allowed_repos:
          - MyOrg/example-app-on-lambda-with-gha
        attributes: ["lambda-cicd"]
        iam_policies:
          - lambda-cicd
        lambda_cicd_policy_configuration:
          enable_ssm_access: true
          enable_s3_access: true
          s3_bucket_component_name: s3-bucket/github-action-artifacts
          s3_bucket_environment_name: gbl
          s3_bucket_stage_name: artifacts
          s3_bucket_tenant_name: core

Example Using an AWS Managed policy and a custom inline policy:

# stacks/catalog/github-oidc-role/custom.yaml
import:
  - catalog/github-oidc-role/defaults

components:
  terraform:
    github-oidc-role/custom:
      metadata:
        component: github-oidc-role
        inherits:
          - github-oidc-role/defaults
      vars:
        enabled: true
        github_actions_allowed_repos:
          - MyOrg/example-app-on-lambda-with-gha
        attributes: ["custom"]
        iam_policies:
          - arn:aws:iam::aws:policy/AdministratorAccess
        iam_policy:
          - version: "2012-10-17"
            statements:
              - effect: "Allow"
                actions:
                  - "ec2:*"
                resources:
                  - "*"

Adding Custom Policies

There are two methods for adding custom policies to the IAM role.

Through the iam_policy input which you can use to add inline policies to the IAM role.
By defining policies in Terraform and then attaching them to roles by name.

Defining Custom Policies in Terraform

Give the policy a unique name, e.g. docker-publish. We will use NAME as a placeholder for the name in the instructions below.
Create a file in the component directory (i.e. github-oidc-role) with the name policy_NAME.tf.

In that file, conditionally (based on need) create a policy document as follows:

locals {
  NAME_policy_enabled = contains(var.iam_policies, "NAME")
  NAME_policy         = local.NAME_policy_enabled ? one(data.aws_iam_policy_document.NAME.*.json) : null
}

data "aws_iam_policy_document" "NAME" {
  count = local.NAME_policy_enabled ? 1 : 0

  # Define the policy here
}

Note that you can also add input variables and outputs to this file if desired. Just make sure that all inputs are optional.

Create a file named additional-policy-map_override.tf in the component 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.
In that file, redefine the local variable overridable_additional_custom_policy_map map as follows:
```
locals {
  overridable_additional_custom_policy_map = {
    "NAME" = local.NAME_policy
  }
}
```
If you have multiple custom policies, using just this one file, add each policy document to the map in the form NAME = local.NAME_policy.
With that done, you can now attach that policy by adding the name to the iam_policies list. For example:
```
iam_policies:
  - "arn:aws:iam::aws:policy/job-function/ViewOnlyAccess"
  - "NAME"
```

Variables

Required Variables

region (string) required: AWS Region

Optional Variables

github_actions_allowed_repos (list(string)) optional

A list of the GitHub repositories that are allowed to assume this role from GitHub Actions. For example,
["cloudposse/infra-live"]. Can contain "*" as wildcard.
If org part of repo name is omitted, "cloudposse" will be assumed.

Default value: [ ]

gitops_policy_configuration optional

Configuration for the GitOps IAM Policy, valid keys are

s3_bucket_component_name - Component Name of where to store the TF Plans in S3, defaults to gitops/s3-bucket
dynamodb_component_name - Component Name of where to store the TF Plans in Dynamodb, defaults to gitops/dynamodb
s3_bucket_environment_name - Environment name for the S3 Bucket, defaults to current environment
dynamodb_environment_name - Environment name for the Dynamodb Table, defaults to current environment

Type:

object({
s3_bucket_component_name   = optional(string, "gitops/s3-bucket")
dynamodb_component_name    = optional(string, "gitops/dynamodb")
s3_bucket_environment_name = optional(string)
dynamodb_environment_name  = optional(string)
})

Default value: { }

iam_policies (list(string)) optional

List of policies to attach to the IAM role, should be either an ARN of an AWS Managed Policy or a name of a custom policy e.g. gitops

Default value: [ ]

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: [ ]

lambda_cicd_policy_configuration optional

Configuration for the lambda-cicd policy. The following keys are supported:

enable_kms_access - (bool) - Whether to allow access to KMS. Defaults to false.
enable_ssm_access - (bool) - Whether to allow access to SSM. Defaults to false.
enable_s3_access - (bool) - Whether to allow access to S3. Defaults to false.
s3_bucket_component_name - (string) - The name of the component to use for the S3 bucket. Defaults to s3-bucket/github-action-artifacts.
s3_bucket_environment_name - (string) - The name of the environment to use for the S3 bucket. Defaults to the environment of the current module.
s3_bucket_tenant_name - (string) - The name of the tenant to use for the S3 bucket. Defaults to the tenant of the current module.
s3_bucket_stage_name - (string) - The name of the stage to use for the S3 bucket. Defaults to the stage of the current module.
enable_lambda_update - (bool) - Whether to allow access to update lambda functions. Defaults to false.

Type:

object({
enable_kms_access          = optional(bool, false)
enable_ssm_access          = optional(bool, false)
enable_s3_access           = optional(bool, false)
s3_bucket_component_name   = optional(string, "s3-bucket/github-action-artifacts")
s3_bucket_environment_name = optional(string)
s3_bucket_tenant_name      = optional(string)
s3_bucket_stage_name       = optional(string)
enable_lambda_update       = optional(bool, false)
})

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

github_actions_iam_role_arn: ARN of IAM role for GitHub Actions
github_actions_iam_role_name: Name of IAM role for GitHub Actions

Dependencies

Requirements

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

Providers

aws, version: >= 4.9.0

Modules

Name	Version	Source	Description
`dynamodb`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a
`gha_assume_role`	latest	`../account-map/modules/team-assume-role-policy`	n/a
`iam_policy`	2.0.1	`cloudposse/iam-policy/aws`	n/a
`iam_roles`	latest	`../account-map/modules/iam-roles`	n/a
`s3_artifacts_bucket`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a
`s3_bucket`	1.5.0	`cloudposse/stack-config/yaml//modules/remote-state`	n/a
`this`	0.25.0	`cloudposse/label/null`	n/a

Resources

The following resources are used by this module:

aws_iam_role.github_actions (resource)

Data Sources

The following data sources are used by this module:

aws_iam_policy_document.gitops_iam_policy (data source)
aws_iam_policy_document.lambda_cicd_policy (data source)

References

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

Usage​

Adding Custom Policies​

Defining Custom Policies in Terraform​

Variables​

Required Variables​

Optional Variables​

Context Variables​

Outputs​

Dependencies​

Requirements​

Providers​

Modules​

Resources​

Data Sources​

References​

Usage

Adding Custom Policies

Defining Custom Policies in Terraform

Variables

Required Variables

Optional Variables

Context Variables

Outputs

Dependencies

Requirements

Providers

Modules

Resources

Data Sources

References