Implement Role Mapping for GitHub OAuth2 Users

[mattknatt]

Goal
Establish a secure mechanism to automatically assign internal roles (ADMIN, HANDLER, CASE_OWNER) to users based on their GitHub identity.

Requirements

• Implement GrantedAuthoritiesMapper: Create a bean in SecurityConfig to intercept the OAuth2 login flow and translate GitHub user attributes into Spring Security roles.

• Define Mapping Logic:

  • Map specific GitHub usernames to ROLE_ADMIN.
  • Default all other authenticated GitHub users to ROLE_CASE_OWNER.

• Configure Security Filter Chain: Register the mapper within the userInfoEndpoint() configuration to ensure roles are assigned immediately upon successful authentication.

• Configurable Admin List: (Optional) Use an environment variable (e.g., GITHUB_ADMIN_USERNAMES) to store the list of admin users so it can be updated without code changes.

• Update Service Layer: Ensure the Actor logic (or @PreAuthorize annotations) can correctly consume these mapped roles for access control.