Create AWS OIDC identity provider and IAM role for Github Actions

tempalte.yml

Parameters:
  GitHubOrg:
    Type: String
  RepositoryName:
    Type: String
  OIDCProviderArn:
    Description: Arn for the GitHub OIDC Provider.
    Default: ""
    Type: String

Conditions:
  CreateOIDCProvider: !Equals 
    - !Ref OIDCProviderArn
    - ""

Resources:
  Role:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Action: sts:AssumeRoleWithWebIdentity
            Principal:
              Federated: !If 
                - CreateOIDCProvider
                - !Ref GithubOidc
                - !Ref OIDCProviderArn
            Condition:
              StringLike:
                token.actions.githubusercontent.com:sub: !Sub repo:${GitHubOrg}/${RepositoryName}:*

  GithubOidc:
    Type: AWS::IAM::OIDCProvider
    Condition: CreateOIDCProvider
    Properties:
      Url: https://token.actions.githubusercontent.com
      ClientIdList: 
        - sts.amazonaws.com
      ThumbprintList:
        - a031c46782e6e6c662c2c87c76da9aa62ccabd8e

Outputs:
  Role:
    Value: !GetAtt Role.Arn