Configure WebSocket Support

Objective

This document provides instructions on how to enable WebSocket-based communication for your application. WebSocket provides a persistent connection between client and server over HTTP or HTTPS.

Using the instructions provided in this guide, you can enable WebSocket connection for your services provisioned using an HTTP load balancer or virtual host. For more information, see Virtual Host.

Note: When configuring WebSocket support, it is recommended to use HTTP/1.1 for origin.

---

Prerequisites

The following prerequisites apply:

• An F5 Distributed Cloud Account. If you do not have an account, see Getting Started with Console.

• An HTTP load balancer or a virtual host acting as a proxy for a service. See HTTP Load Balancer and Create a Virtual Host for instructions on creating load balancer and virtual host, respectively.

---

Configuration Sequence

You can use an HTTP load balancer or virtual host to configure WebSocket support for your application.

• In case of HTTP load balancer, enabling WebSocket support is part of the HTTP load balancer configuration.

• Enabling WebSocket-based communication in case of a virtual host requires performing the following sequence of actions:

Phase	Description
Create Endpoint and Cluster	Create objects required for virtual host.
Create Route with WebSocket	Create route enabled for WebSocket communication.
Create Advertise Policy and Virtual Host	Create advertise policy and virtual host with the route and policy.

Note: You can enable WebSocket communication while creating the route, or you can edit an existing route to enable WebSocket support.

---

Configure WebSocket Using HTTP Load Balancer

Note: A server must not send a Transfer-Encoding header field in any response with a status code of 1xx (Informational) or 204 (No Content). A server must not send a Transfer-Encoding header field in any 2xx (Successful) response to a CONNECT request (Section 4.3.6 of RFC 7231).

Perform the following steps to create a route enabled with WebSocket support for an HTTP Load Balancer:

Step 1: Log into Console and go to HTTP load balancer settings.

• From the Console homepage, click Multi-Cloud App Connect.

Figure: Console Homepage

• Select a namespace.

• Navigate to Manage > Load Balancers > HTTP Load Balancers.

• Click ... for your load balancer and select Manage Configuration to open the load balancer configuration form.

• Click Edit Configuration in the top right corner of the form.

Step 2: Start configuring routes.

• In the Routes section, click Configure.

• Click Add Item in the Routes page. This opens the route configuration form. By default, a simple route configuration loads.

• Enter required fields, such as HTTP method, path match, and option associated to the path match selected (such as prefix, path, or regex).

• Click Add item in Origin Pools section, select an origin pool from the Origin Pool menu, and then click Apply.

Figure: HTTP Load Balancer Simple Route

• Scroll down and click Configure for the Advanced Options field. This opens the advanced route configuration options.

• Scroll down to the Protocol Upgrades section and click on the Enable/Disable Websocket Upgrade menu, and then select the Enable WebSocket option.

Figure: Load Balancer WebSocket Configuration

• Enable the Use Websocket option.

• Scroll down and click Apply.

Step 3: Enable WebSocket communication.

• Click Apply in the simple route page.

• Click Apply in the routes list page.

• Click Save and Exit in the load balancer configuration form.

---

Concepts

• System Overview
• Core Concepts
• Virtual Host

---

API References

• Endpoint
• Cluster
• Routes
• Advertise Policy
• Virtual Host