backend: change the default backend plugin mount point to /api

plugins/auth-backend/README.md

@@ -34,7 +34,7 @@ Follow this link, [Create new OAuth App](https://github.com/settings/application
 1. Set Application Name to `backstage-dev` or something along those lines.
 1. You can set the Homepage URL to whatever you want to.
 1. The Authorization Callback URL should match the redirect URI set in Backstage.
-   1. Set this to `http://localhost:7000/auth/github` for local development.
+   1. Set this to `http://localhost:7000/api/auth/github` for local development.
    1. Set this to `http://{APP_FQDN}:{APP_BACKEND_PORT}/auth/github` for non-local deployments.
 
 ```bash
@@ -78,14 +78,14 @@ export AUTH_AUTH0_CLIENT_SECRET=x
 
 #### Creating an Azure AD App Registration
 
-An Azure AD App Registration is required to be able to sign in using Azure AD and the Microsoft Graph API.  
+An Azure AD App Registration is required to be able to sign in using Azure AD and the Microsoft Graph API.
 Click [here](https://portal.azure.com/#blade/Microsoft_AAD_IAM/ActiveDirectoryMenuBlade/RegisteredApps) to create a new one.
 
 - Click on the `New Registration` button.
 - Give the app a name. e.g. `backstage-dev`
 - Select `Accounts in this organizational directory only` under supported account types.
 - Enter the callback URL for your backstage backend instance:
-  - For local development, this is likely `http://localhost:7000/auth/microsoft/handler/frame`
+  - For local development, this is likely `http://localhost:7000/api/auth/microsoft/handler/frame`
   - For non-local deployments, this will be `https://{APP_FQDN}:{APP_BACKEND_PORT}/auth/microsoft/handler/frame`
 - Click `Register`.
 

plugins/auth-backend/scripts/start-saml-idp.sh

@@ -18,4 +18,4 @@ fi
 
 echo "Downloading and starting SAML-IdP"
 export NPM_CONFIG_REGISTRY=https://registry.npmjs.org
-exec npx saml-idp --acsUrl "http://localhost:7000/auth/saml/handler/frame" --audience "http://localhost:7000" --port 7001
+exec npx saml-idp --acsUrl "http://localhost:7000/api/auth/saml/handler/frame" --audience "http://localhost:7000" --port 7001

plugins/auth-backend/src/service/router.ts

@@ -28,6 +28,7 @@ export interface RouterOptions {
   logger: Logger;
   database: Knex;
   config: Config;
+  basePath?: string;
 }
 
 export async function createRouter(
@@ -38,7 +39,8 @@ export async function createRouter(
 
   const appUrl = options.config.getString('app.baseUrl');
   const backendUrl = options.config.getString('backend.baseUrl');
-  const authUrl = `${backendUrl}/auth`;
+  // TODO(Rugvip): Replace with service discovery of external URL
+  const authUrl = backendUrl + (options.basePath ?? '/api/auth');
 
   const keyDurationSeconds = 3600;