oidc: Provide custom error page

src/oidc.js

@@ -105,7 +105,7 @@ class CloudronAdapter {
         } else {
             this.fileStorePath = path.join(paths.OIDC_STORE_DIR, `${name}.json`);
 
-            debug(`Creating adapter for ${name} backed by ${this.fileStorePath}`);
+            debug(`Creating storage adapter for ${name} backed by ${this.fileStorePath}`);
 
             let data = {};
             try {
@@ -512,6 +512,27 @@ async function postLogoutSuccessSource(ctx) {
     ctx.body = ejs.render(fs.readFileSync(path.join(__dirname, 'oidc_templates/post_logout.ejs'), 'utf8'), data, {});
 }
 
+async function findAccount(ctx, id) {
+    debug(`findAccount id:${id}`);
+
+    return {
+        accountId: id,
+        async claims(use, scope) { return await claims(id, use, scope); },
+    };
+}
+
+async function renderError(ctx, out, error) {
+    const data = {
+        dashboardOrigin: settings.dashboardOrigin(),
+        error
+    };
+
+    debug('renderError:', error);
+
+    ctx.type = 'html';
+    ctx.body = ejs.render(fs.readFileSync(path.join(__dirname, 'oidc_templates/error.ejs'), 'utf8'), data, {});
+}
+
 async function start() {
     const app = express();
 
@@ -520,14 +541,8 @@ async function start() {
     const { Provider } = await import('oidc-provider');
 
     const configuration = {
-        async findAccount(ctx, id) {
-            debug(`findAccount id:${id}`);
-
-            return {
-                accountId: id,
-                async claims(use, scope) { return await claims(id, use, scope); },
-            };
-        },
+        findAccount,
+        renderError,
         adapter: CloudronAdapter,
         interactions: {
             url: async function(ctx, interaction) {