config: new API endpoint

This adds PATCH and GET endpoints to handle `config.json`.

app/server/lib/ConfigBackendAPI.ts

@@ -0,0 +1,35 @@
+import * as express from 'express';
+import {expressWrap} from 'app/server/lib/expressWrap';
+
+import {getGlobalConfig} from 'app/server/lib/globalConfig';
+
+import log from "app/server/lib/log";
+
+export class ConfigBackendAPI {
+  public addEndpoints(app: express.Express, requireInstallAdmin: express.RequestHandler) {
+    app.get('/api/config/:key', requireInstallAdmin, expressWrap((req, resp) => {
+      log.debug('config: requesting configuration', req.params);
+
+      // Only one key is valid for now
+      if (req.params.key === 'edition') {
+        resp.send({value: getGlobalConfig().edition.get()});
+      } else {
+        resp.status(404).send({ error: 'Configuration key not found.' });
+      }
+    }));
+
+    app.patch('/api/config', requireInstallAdmin, expressWrap(async (req, resp) => {
+      const config = req.body.config;
+      log.debug('config: received new configuration item', config);
+
+      // Only one key is valid for now
+      if(config.edition !== undefined) {
+        await getGlobalConfig().edition.set(config.edition);
+
+        resp.send({ msg: 'ok' });
+      } else {
+        resp.status(400).send({ error: 'Invalid configuration key' });
+      }
+    }));
+  }
+}

app/server/lib/FlexServer.ts

@@ -87,7 +87,8 @@ import {AddressInfo} from 'net';
 import fetch from 'node-fetch';
 import * as path from 'path';
 import * as serveStatic from "serve-static";
-import {IGristCoreConfig} from "./configCore";
+import {ConfigBackendAPI} from "app/server/lib/ConfigBackendAPI";
+import {IGristCoreConfig} from "app/server/lib/configCore";
 
 // Health checks are a little noisy in the logs, so we don't show them all.
 // We show the first N health checks:
@@ -1948,6 +1949,14 @@ export class FlexServer implements GristServer {
     }));
   }
 
+  public addConfigEndpoints() {
+    // Need to be an admin to change the Grist config
+    const requireInstallAdmin = this.getInstallAdmin().getMiddlewareRequireAdmin();
+
+    const configBackendAPI = new ConfigBackendAPI();
+    configBackendAPI.addEndpoints(this.app, requireInstallAdmin);
+  }
+
   // Get the HTML template sent for document pages.
   public async getDocTemplate(): Promise<DocTemplate> {
     const page = await fse.readFile(path.join(getAppPathTo(this.appRoot, 'static'),

app/server/mergedServerMain.ts

@@ -165,6 +165,7 @@ export async function main(port: number, serverTypes: ServerType[],
       server.addLogEndpoint();
       server.addGoogleAuthEndpoint();
       server.addInstallEndpoints();
+      server.addConfigEndpoints();
     }
 
     if (includeDocs) {