Add backstage-cli config:check --deprecated to list deprecated settings

Signed-off-by: Colton Padden <colton.padden@fastmail.com>

packages/cli/src/commands/config/validate.ts

@@ -23,5 +23,6 @@ export default async (cmd: Command) => {
     fromPackage: cmd.package,
     mockEnv: cmd.lax,
     fullVisibility: !cmd.frontend,
+    withDeprecatedKeys: cmd.deprecated,
   });
 };

packages/cli/src/commands/index.ts

@@ -193,6 +193,7 @@ export function registerCommands(program: CommanderStatic) {
     )
     .option('--lax', 'Do not require environment variables to be set')
     .option('--frontend', 'Only validate the frontend configuration')
+    .option('--deprecated', 'Output deprecated configuration settings')
     .option(...configOption)
     .description(
       'Validate that the given configuration loads and matches schema',

packages/cli/src/lib/config.ts

@@ -28,6 +28,7 @@ type Options = {
   fromPackage?: string;
   mockEnv?: boolean;
   withFilteredKeys?: boolean;
+  withDeprecatedKeys?: boolean;
   fullVisibility?: boolean;
 };
 
@@ -82,6 +83,7 @@ export async function loadCliConfig(options: Options) {
         ? ['frontend', 'backend', 'secret']
         : ['frontend'],
       withFilteredKeys: options.withFilteredKeys,
+      withDeprecatedKeys: options.withDeprecatedKeys,
     });
     const frontendConfig = ConfigReader.fromConfigs(frontendAppConfigs);