Enable code tab docs

content/deployment/configuration/code-viewer.md

@@ -0,0 +1,97 @@
+---
+title: Code Viewer
+weight: 1
+variants: -flyte -serverless -byoc +selfmanaged
+---
+
+# Code Viewer
+One of the powerful capabilities in the Union UI is the ability to view the exact code that ran a particular task.
+Union Union implements a secure mechanism to transfer the [code bundle](../../user-guide/run-scaling/life-of-a-run.md/#phase-2-image-building) to the browser without passing through the control plane.
+
+![Code Viewer](../../_static/images/deployment/configuration/code-viewer/demo.png)
+
+## Enable CORS policy on your fast registration bucket
+In order to support this functionality securely, your bucket must allow CORS access for Union. Depending on which cloud the bucket is located in, these configurations vary.
+
+{{< tabs "bucket-cors-policy" >}}
+{{< tab "AWS S3 Console" >}}
+{{< markdown >}}
+1. Access AWS Console
+2. Access S3 dashboard
+3. Choose the fast registration bucket. Unless configured differently, this is the same as the metadata bucket configured when you first
+    deployed.
+4. Click on "Permissions" tab and scroll to "CORS Policy"
+5. Click on Edit and enter the policy below
+![S3 CORS Policy](../../_static/images/deployment/configuration/code-viewer/s3.png)
+```
+[
+    {
+        "AllowedHeaders": [
+            "*"
+        ],
+        "AllowedMethods": [
+            "GET",
+            "HEAD",
+        ],
+        "AllowedOrigins": [
+            "https://*.unionai.cloud"
+        ],
+        "ExposeHeaders": [
+            "ETag"
+        ],
+        "MaxAgeSeconds": 3600
+    }
+]
+```
+Further reference: [AWS Guide on S3 CORS Policy](https://docs.aws.amazon.com/AmazonS3/latest/userguide/cors.html)
+{{< /markdown >}}
+{{< /tab >}}
+{{< tab "Google GCS" >}}
+{{< markdown >}}
+Google GCS does not allow changing the bucket policy through the console.
+1. Create a cors.json configuration file and paste the content below
+    ```json
+    [
+        {
+        "origin": ["https://*.unionai.cloud"],
+        "method": ["HEAD", "GET"],
+        "responseHeader": ["ETag"],
+        "maxAgeSeconds": 3600
+        }
+    ]
+    ```
+2. Apply the cors configuration:
+    ```bash
+    gcloud storage buckets update gs://<fast_registration_bucket> --cors-file=cors.json
+    ```
+3. View configuration to confirm:
+   ```bash
+   gcloud storage buckets describe gs://<fast_registration_bucket> --format="default(cors_config)"
+
+   cors_config:
+   - maxAgeSeconds: 3600
+     method:
+     - GET
+     - HEAD
+     origin:
+     - https://*.unionai.cloud
+     responseHeader:
+     - ETag
+   ```
+Further reference: [Google Guide on GCS CORS Policy](https://docs.cloud.google.com/storage/docs/using-cors#command-line)
+{{< /markdown >}}
+{{< /tab >}}
+{{< tab "Azure Storage" >}}
+{{< markdown >}}
+Further reference: [Azure Guide on Storage CORS Policy](https://learn.microsoft.com/en-us/rest/api/storageservices/cross-origin-resource-sharing--cors--support-for-the-azure-storage-services)
+{{< /markdown >}}
+{{< /tab >}}
+{{< /tabs >}}
+
+## Troubleshooting
+
+| Error Message | Cause | Fix |
+|---------------|-------|-----|
+| `Not available: No code available for this action.` | The underlying task doesn't have a code bundle, this could be because all code is already in the underlying docker image or the task isn't a code task. | Expected behavior for non-code-bundled tasks |
+| `Not Found: The code bundle file could not be found. This may be due to your organization's data retention policy.` | The task does use a code bundle but the underlying bundle isn't found in the bucket. | Check fast registration bucket retention policy |
+| `Error: Code download is blocked by your storage bucket's configuration. Please contact your administrator to enable access.` | CORS isn't properly configured on the bucket | Refer to the above guide to enable CORS. |