Output a JSON schema from the .well-known metadata endpoint

Signed-off-by: Harry Hogg <hhogg@spotify.com>

plugins/permission-node/package.json

@@ -41,7 +41,8 @@
     "@types/express": "^4.17.6",
     "express": "^4.17.1",
     "express-promise-router": "^4.1.0",
-    "zod": "^3.11.6"
+    "zod": "^3.11.6",
+    "zod-to-json-schema": "^3.18.1"
   },
   "devDependencies": {
     "@backstage/backend-test-utils": "workspace:^",

plugins/permission-node/src/integration/createPermissionIntegrationRouter.test.ts

@@ -530,12 +530,42 @@ describe('createPermissionIntegrationRouter', () => {
             name: testRule1.name,
             description: testRule1.description,
             resourceType: testRule1.resourceType,
+            schema: {
+              $schema: 'http://json-schema.org/draft-07/schema#',
+              items: [
+                {
+                  description: 'firstParam',
+                  type: 'string',
+                },
+                {
+                  description: 'secondParam',
+                  type: 'number',
+                },
+              ],
+              maxItems: 2,
+              minItems: 2,
+              type: 'array',
+            },
             parameters: { count: 2 },
           },
           {
             name: testRule2.name,
             description: testRule2.description,
             resourceType: testRule2.resourceType,
+            schema: {
+              $schema: 'http://json-schema.org/draft-07/schema#',
+              items: [
+                {
+                  additionalProperties: false,
+                  description: 'firstParam',
+                  properties: {},
+                  type: 'object',
+                },
+              ],
+              maxItems: 1,
+              minItems: 1,
+              type: 'array',
+            },
             parameters: { count: 1 },
           },
         ],

plugins/permission-node/src/integration/createPermissionIntegrationRouter.ts

@@ -17,6 +17,7 @@
 import express, { Response } from 'express';
 import Router from 'express-promise-router';
 import { z } from 'zod';
+import zodToJsonSchema from 'zod-to-json-schema';
 import { InputError } from '@backstage/errors';
 import { errorHandler } from '@backstage/backend-common';
 import {
@@ -201,6 +202,7 @@ export const createPermissionIntegrationRouter = <
       name: rule.name,
       description: rule.description,
       resourceType: rule.resourceType,
+      schema: zodToJsonSchema(rule.schema),
       parameters: {
         count: rule.toQuery.length,
       },