POC: Add auth_request example

Author: nginx-jack

exampleSite/content/njs/auth-request.md

@@ -0,0 +1,28 @@
+---
+description: Auth Request
+title: Auth Request
+weight: 100
+---
+
+In this example, when a client sends a request to the `/auth` endpoint, NGINX calls the `choose_upstream` function. This function reads the token from the request's query string and then selects the appropriate backend server based on the token's value. If the token does not match a known value, the function returns a 404 error.
+
+```nginx
+load_module modules/ngx_http_js_module.so;
+
+events {}
+
+http {
+    js_import http.js;
+
+    server {
+        listen 8000;
+
+        location /auth {
+            js_content http.auth;
+        }
+    }
+}
+```
+
+
+{{< njs-playground exampleNJS=auth_request.js fnName=choose_upstream >}}

exampleSite/content/njs/basic-example.md

@@ -4,9 +4,7 @@ title: Basic Example
 weight: 100
 ---
 
-
-To use njs in nginx:
-- [install](https://nginx.org/en/docs/njs/install.html) njs scripting language
+In this example, the client sends a request to `/`, which calls the `hello` njs function. By default, the function returns status code `200` and the message `Hello World`.
 
 
 ```nginx

exampleSite/content/njs/echo-server.md

@@ -4,8 +4,7 @@ title: Echo Server
 weight: 100
 ---
 
-This example demonstrates how to create a simple echo endpoint.  
-The endpoint returns the details of the request sent to NGINX as JSON.  
+This example shows how to create a simple echo endpoint. The client sends a request to the `/echo` endpoint, which calls the `echo` njs function. By default, this function returns the request details received by NGINX in JSON format.
 
 ```nginx
 load_module modules/ngx_http_js_module.so;

exampleSite/content/njs/magic-ai-thing.md

@@ -0,0 +1,33 @@
+function choose_upstream(r) {
+    let backend;
+  
+    let uriParts = r.headersIn['X-Original-URI'].split('?');
+    if (uriParts.length < 2) {
+        return r.return(404);
+    }
+    
+    let queryString = uriParts[1];
+    let args = {};
+    
+    queryString.split('&').forEach(part => {
+        let [key, value] = part.split('=');
+        args[decodeURIComponent(key)] = decodeURIComponent(value || '');
+    });
+
+    switch (args.token) {
+        case 'A':
+            backend = '127.0.0.1:8081';
+            break;
+        case 'B':
+            backend = '127.0.0.1:8082';
+            break;
+        default:
+            return r.return(404);
+    }
+
+    r.headersOut['X-backend'] = backend;
+    return r.return(200, r.headersOut);
+}
+
+// uncomment for us in NJS
+// export default { choose_upstream };

exampleSite/static/njs/auth_request.js

@@ -20,7 +20,7 @@ function echo(r) {
 		version: httpVersion,
 	};
 
-	return r.return(200, JSON.stringify(response));
+	return r.return(200, response);
 }
 
 // uncomment for use in NJS

exampleSite/static/njs/echo.js

@@ -12,7 +12,7 @@ <h3>Request Builder</h3>
     </select>
 
     <label for="url">URI:</label>
-    <input id="url" type="text" placeholder="/echo">
+    <input id="url" type="text" placeholder="/api">
 
     <label for="bodyJSON">JSON Body:</label>
     <textarea id="bodyJSON" rows="8" placeholder='{"example":"value"}'></textarea>
@@ -42,6 +42,7 @@ <h3>NJS Function</h3>
     const bodyEl = document.getElementById('bodyJSON');
     const headersContainerEl = document.getElementById('headers-container');
     const addHeaderBtn = document.getElementById('add-header');
+
     // Initialize headers with one empty pair
     addHeaderField();
 
@@ -95,7 +96,7 @@ <h3>NJS Function</h3>
         const requestObject = {
             method: methodEl.value,
             uri: urlEl.value,
-            headersIn: headers,
+            headersIn: headers || {},
             body: bodyContent
         };
 
@@ -148,6 +149,7 @@ <h3>NJS Function</h3>
                     ...request,
                     requestText: request.body,
                     return: (status, value) => (JSON.stringify({status, value})),
+                    headersOut: {},
                 }
             }
                 {{ .fnName }}(requestConverter(exampleRequest))