# Networking with Load Balancers

Lenses uses Websockets. It can be that your load balancers block them by default. Depending on your load balancer you need to allow websockets.

For example on NGINX:

```yaml
annotations:
  kubernetes.io/ingress.class: nginx
  nginx.ingress.kubernetes.io/proxy-read-timeout: "3600"
  nginx.ingress.kubernetes.io/proxy-send-timeout: "3600"
```

{% hint style="info" %}
If it is exposed via a service type *LoadBalancer*, ensure the protocol between the load balancer and NGINX is set to TCP. See Kubernetes [documentation ](https://kubernetes.github.io/ingress-nginx/user-guide/miscellaneous/#websockets)for more information.
{% endhint %}

Lenses can be placed behind a proxy, but you must allow websocket connections.

These two paths are used for WebSocket connections:

* `/api/ws`
* `/api/kafka/ws`

Disable proxy buffering for SSE (Server Sent Events) connections on this path:

* `/api/sse`

### TLS termination

Lenses supports TLS termination out of the box, see Enabling TLS

### Sample Apache configuration

```bash
# Add these settings to your httpd.conf or under the VirtualHost section
# for Lenses.
# The rewrite directives need the rewrite module:
#   LoadModule rewrite_module modules/mod_rewrite.so
# The proxy directives need the proxy, proxy_http and proxy_wstunnel modules:
#   LoadModule proxy_module modules/mod_proxy.so
#   LoadModule proxy_http_module modules/mod_proxy_http.so
#   LoadModule proxy_wstunnel_module modules/mod_proxy_wstunnel.so

RewriteEngine On
RewriteCond %{HTTP:Upgrade} =websocket [NC]
RewriteRule ^/(.*)$           ws://lenses.url:9991/$1 [P,L]
RewriteCond %{HTTP:Upgrade} !=websocket [NC]
RewriteRule ^/(.*)$           http://lenses.url:9991/$1 [P,L]

ProxyRequests On
ProxyPreserveHost On
ProxyPass / http://lenses.url:9991/
ProxyPassReverse / http://lenses.url:9991/
```

### Sample Caddy configuration

```bash
proxy /api/kafka/ws http://lenses.url:9991 {
    websocket
}
proxy /api/ws http://lenses.url:9991 {
    websocket
}
proxy / http://lenses.url:9991
```

### Sample NGINX configuration

```bash
map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
}

server {
    listen 80;
    server_name example.lenses.url;

    # websocket paths
    location /api/ws {
        proxy_pass http://lenses.url:9991;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;

        proxy_redirect off;
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header  Host $http_host;
    }
    location /api/kafka/ws {
        proxy_pass http://lenses.url:9991;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;

        proxy_redirect off;
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header  Host $http_host;
    }

    # SSE paths
    location /api/sse {
        proxy_pass http://lenses.url:9991;
        proxy_http_version 1.1;

        proxy_buffering off;
        proxy_redirect off;
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header  Host $http_host;
    }

    # all other paths
    location / {
        proxy_pass http://lenses.url:9991;
        proxy_http_version 1.1;

        proxy_redirect off;
        proxy_set_header  X-Real-IP  $remote_addr;
        proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header  Host $http_host;
    }
}
```


---

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```
GET https://docs.lenses.io/latest/deployment/configuration/agent/networking-with-load-balancers.md?ask=<question>
```

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