Set up authentication for Tanzu Developer Portal

Tanzu Developer Portal extends the current Backstage authentication plug-in so that you can see a login page based on the authentication providers configured at installation. This feature is a work in progress.

Tanzu Developer Portal currently supports the following authentication providers:

You can also configure a custom OpenID Connect (OIDC) provider.

View your Backstage Identity

A Backstage identity is defined as a combination of:

The user reference: each entity in the catalog is uniquely identified by the triplet of its kind
A namespace
A name

For example, the user Jane can be assigned to the user entity user:default/jane and an ownership reference, which is used to determine what that user owns. Jane (user:default/jane) might have the ownership references user:default/jane, group:default/team-a, and group:default/admins. This would mean that Jane belongs to those groups and, therefore, owns those references.

To view your current Backstage identity, in the Settings section of the left side navigation pane click the General tab.

Screenshot of a Tanzu Application Platform catalog displayed within Tanzu Developer Portal.

Configure an authentication provider

Configure a supported authentication provider or a custom OIDC provider:

To configure a supported authentication provider, see the Backstage authentication documentation.
To configure a custom OIDC provider, edit your tap-values.yaml file or your custom configuration file to include an OIDC authentication provider. Configure the OIDC provider with your OAuth App values. For example:
```
shared:
  ingress_domain: "INGRESS-DOMAIN"

# ... any existing values

tap_gui:
  # ... any other Tanzu Developer Portal values
  app_config:
    auth:
      environment: development
      session:
        secret: custom session secret
      providers:
        oidc:
          development:
            metadataUrl: AUTH-OIDC-METADATA-URL
            clientId: AUTH-OIDC-CLIENT-ID
            clientSecret: AUTH-OIDC-CLIENT-SECRET
            tokenSignedResponseAlg: AUTH-OIDC-TOKEN-SIGNED-RESPONSE-ALG # default='RS256'
            scope: AUTH-OIDC-SCOPE # default='openid profile email'
            prompt: auto # default=none (allowed values: auto, none, consent, login)
```
Where AUTH-OIDC-METADATA-URL is a JSON file with generic OIDC provider configuration. It contains authorizationUrl and tokenUrl. Tanzu Developer Portal reads these values from metadataUrl, so you must not specify these values explicitly in the earlier authentication configuration.

You must also the provide the redirect URI of the Tanzu Developer Portal instance to your identity provider. The redirect URI is sometimes called the redirect URL, the callback URL, or the callback URI. The redirect URI takes the following form:
```
SCHEME://tap-gui.INGRESS-DOMAIN/api/auth/oidc/handler/frame
```
Where:
- SCHEME is the URI scheme, most commonly http or https
- INGRESS-DOMAIN is the host name you selected for your Tanzu Developer Portal instance
When using https and example.com as examples for the two placeholders respectively, the redirect URI reads as follows:
```
https://tap-gui.example.com/api/auth/oidc/handler/frame
```
For more information, see this example in GitHub.
(Optional) Configure offline access scope for the OIDC provider by adding the scope parameter offline_access to either tap-values.yaml or your custom configuration file. For example:
```
auth:
  providers:
    oidc:
      development:
        ... # auth configs
        scope: 'openid profile email offline_access'
```
By default, scope is not configured to provide persistence to user login sessions, such as in the case of a page refresh. Not all identity providers support the offline_access scope. For more information, see your identity provider documentation.

(Optional) Allow guest access

Enable guest access with other providers by adding the following flag under your authentication configuration:

auth:
  allowGuestAccess: true

(Optional) Customize the login page

Change the card’s title or description for a specific provider with the following configuration:

auth:
  environment: development
  providers:
    ... # auth providers config
  loginPage:
    github:
      title: Github Login
      message: Enter with your GitHub account

For a provider to appear on the login page, ensure that it is properly configured under the auth.providers section of your values file.