Component: github-oidc-provider

This component is responsible for authorizing the GitHub OIDC provider as an Identity provider for an AWS account. It is meant to be used in concert with aws-teams and aws-team-roles and/or with github-actions-iam-role.mixin.tf

Usage

Stack Level: Global

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

• This must be installed in the identity account in order to use standard SAML roles with role chaining.
• This must be installed in each individual account where you want to provision a service role for a GitHub action that will be assumed directly by the action.

For security, since this component adds an identity provider, only SuperAdmin can install it.

components:
  terraform:
    github-oidc-provider:
      vars:
        enabled: true

Configuring the Github OIDC Provider

This component was created to add the Github OIDC provider so that Github Actions can safely assume roles without the need to store static credentials in the environment. The details of the GitHub OIDC provider are hard coded in the component, however at some point the provider's thumbprint may change, at which point you can use get_github_oidc_thumbprint.sh to get the new thumbprint and add it to the list in var.thumbprint_list.

This script will pull one of two thumbprints. There are two possible intermediary certificates for the Actions SSL certificate and either can be returned by the GitHub servers, requiring customers to trust both. This is a known behavior when the intermediary certificates are cross-signed by the CA. Therefore, run this script until both values are retrieved. Add both to var.thumbprint_list.

For more, see https://github.blog/changelog/2023-06-27-github-actions-update-on-oidc-integration-with-aws/

FAQ

I cannot assume the role from GitHub Actions after deploying

The following error is very common if the GitHub workflow is missing proper permission.

Error: User: arn:aws:sts::***:assumed-role/acme-core-use1-auto-actions-runner@actions-runner-system/token-file-web-identity is not authorized to perform: sts:TagSession on resource: arn:aws:iam::999999999999:role/acme-plat-use1-dev-gha

In order to use a web identity, GitHub Action pipelines must have the following permission. See GitHub Action documentation for more.

permissions:
  id-token: write # This is required for requesting the JWT
  contents: read # This is required for actions/checkout

Requirements

Name	Version
terraform	>= 1.0.0
aws	>= 4.9.0

Providers

Name	Version
aws	>= 4.9.0

Modules

Name	Source	Version
iam_roles	../account-map/modules/iam-roles	n/a
this	cloudposse/label/null	0.25.0

Resources

Name	Type
aws_iam_openid_connect_provider.oidc	resource

Inputs

Name	Description	Type	Default	Required
additional_tag_map	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.	map(string)	{}	no
attributes	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.	list(string)	[]	no
context	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.	any	{ "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 }	no
delimiter	Delimiter to be used between ID elements. Defaults to - (hyphen). Set to "" to use no delimiter at all.	string	null	no
descriptor_formats	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).	any	{}	no
enabled	Set to false to prevent the module from creating any resources	bool	null	no
environment	ID element. Usually used for region e.g. 'uw2', 'us-west-2', OR role 'prod', 'staging', 'dev', 'UAT'	string	null	no
id_length_limit	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.	number	null	no
label_key_case	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.	string	null	no
label_order	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.	list(string)	null	no
label_value_case	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.	string	null	no
labels_as_tags	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.	set(string)	[ "default" ]	no
name	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.	string	null	no
namespace	ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique	string	null	no
regex_replace_chars	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.	string	null	no
region	AWS Region	string	n/a	yes
stage	ID element. Usually used to indicate role, e.g. 'prod', 'staging', 'source', 'build', 'test', 'deploy', 'release'	string	null	no
superadmin	Set true if running as the SuperAdmin user	bool	false	no
tags	Additional tags (e.g. {'BusinessUnit': 'XYZ'}). Neither the tag keys nor the tag values will be modified by this module.	map(string)	{}	no
tenant	ID element _(Rarely used, not included by default)_. A customer identifier, indicating who this instance of a resource is for	string	null	no
thumbprint_list	List of OIDC provider certificate thumbprints	list(string)	[ "6938fd4d98bab03faadb97b34396831e3780aea1", "1c58a3a8518e8759bf075b76b750d4f2df264fcd" ]	no

Outputs

Name	Description
oidc_provider_arn	GitHub OIDC provider ARN

References

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