nginx · haywoodsh · May 13, 2026 · May 5, 2026 · May 12, 2026 · May 12, 2026
@@ -32,6 +32,8 @@ Secret with a TLS certificate and key for TLS termination of the default server.
 
 Format: `<namespace>/<name>`
 
+When `-allow-empty-ingress-host` is enabled, this secret also provides TLS for Ingress resources without a `host`.
+
 <a name="cmdoption-wildcard-tls-secret"></a>
 
 ### -wildcard-tls-secret `<string>`
@@ -165,6 +167,16 @@ Default `nginx`.
 
 Path to the ingress NGINX configuration template for an ingress resource. Default for NGINX is `nginx.ingress.tmpl`; default for NGINX Plus is `nginx-plus.ingress.tmpl`.
 
+### -allow-empty-ingress-host {#cmdoption-allow-empty-ingress-host}
+
+Allows Ingress resources to omit the `host` field.
+
+Default `false`.
+
+If multiple Ingress resources without a `host` conflict, NGINX Ingress Controller resolves the collision using the [winner selection algorithm]({{< ref "/nic/configuration/host-and-listener-collisions.md" >}}). To use multiple Ingress resources without a `host` across namespaces without conflict, use [mergeable Ingress]({{< ref "/nic/configuration/ingress-resources/cross-namespace-configuration.md" >}}).
+
+To configure TLS, use the command-line argument [`-default-server-tls-secret`](#cmdoption-default-server-tls-secret). To configure listener ports, use the command-line arguments [`-default-http-listener-port`](#cmdoption-default-http-listener-port) or [`-default-https-listener-port`](#cmdoption-default-https-listener-port).
+
 <a name="cmdoption-leader-election-lock-name"></a>
 
 ### -leader-election-lock-name `<string>`
@@ -509,6 +521,8 @@ Sets the port for the HTTP `default_server` listener.
 
 Default `80`.
 
+When [-allow-empty-ingress-host](#cmdoption-allow-empty-ingress-host) is enabled, also configures the HTTP listener port for Ingress resources without a `host`.
+
 <a name="cmdoption-default-http-listener-port"></a>
 
 ### -default-https-listener-port
@@ -517,6 +531,8 @@ Sets the port for the HTTPS `default_server` listener.
 
 Default `443`.
 
+When [-allow-empty-ingress-host](#cmdoption-allow-empty-ingress-host) is enabled, also configures the HTTPS listener port for Ingress resources without a `host`.
+
 <a name="cmdoption-default-https-listener-port"></a>
 
 ### -ssl-dynamic-reload

@@ -77,7 +77,7 @@ For more information, view the [VirtualServer and VirtualServerRoute resources](
 |*set-real-ip-from* | Sets the value of the [set_real_ip_from](https://nginx.org/en/docs/http/ngx_http_realip_module.html#set_real_ip_from) directive. | N/A |  |
 |*real-ip-header* | Sets the value of the [real_ip_header](https://nginx.org/en/docs/http/ngx_http_realip_module.html#real_ip_header) directive. | *X-Real-IP* |  |
 |*real-ip-recursive* | Enables or disables the [real_ip_recursive](https://nginx.org/en/docs/http/ngx_http_realip_module.html#real_ip_recursive) directive. | *False* |  |
-|*default-server-return* | Configures the [return](https://nginx.org/en/docs/http/ngx_http_rewrite_module.html#return)  directive in the default server, which handles a client request if none of the hosts of Ingress or VirtualServer resources match. The default value configures NGINX to return a 404 error page. You can configure a fixed response or a redirect. For example, *default-server-return: 302 https://nginx.org* will redirect a client to *https://nginx.org*. | *404* |  |
+|*default-server-return* | Configures the [return](https://nginx.org/en/docs/http/ngx_http_rewrite_module.html#return)  directive in the default server, which handles a client request if none of the hosts of Ingress or VirtualServer resources match. The default value configures NGINX to return a 404 error page. You can configure a fixed response or a redirect. For example, *default-server-return: 302 https://nginx.org* will redirect a client to *https://nginx.org*. When [-allow-empty-ingress-host](https://docs.nginx.com/nginx-ingress-controller/configuration/global-configuration/command-line-arguments/#cmdoption-allow-empty-ingress-host) is enabled and an empty-host Ingress is active, this directive applies to requests that do not match any Ingress path, unless the Ingress defines a `/` path or `spec.defaultBackend`. | *404* |  |
 |*server-tokens* | Enables or disables the [server_tokens](https://nginx.org/en/docs/http/ngx_http_core_module.html#server_tokens) directive. Additionally, with the NGINX Plus, you can specify a custom string value, including the empty string value, which disables the emission of the “Server” field. | *True* |  |
 |*worker-processes* | Sets the value of the [worker_processes](https://nginx.org/en/docs/ngx_core_module.html#worker_processes) directive. | *auto* |  |
 |*worker-rlimit-nofile* | Sets the value of the [worker_rlimit_nofile](https://nginx.org/en/docs/ngx_core_module.html#worker_rlimit_nofile) directive. | N/A |  |

@@ -21,7 +21,7 @@ If multiple resources contend for the same host or listener, NGINX Ingress Contr
 
 ## Host collisions
 
-A host collision occurs when multiple Ingress, VirtualServer, and TransportServer (configured for TLS Passthrough) resources configure the same `host`. NGINX Ingress Controller has two strategies for handling host collisions:
+A host collision occurs when multiple Ingress, VirtualServer, and TransportServer (configured for TLS Passthrough) resources configure the same `host`. When [`-allow-empty-ingress-host`]({{< ref "/nic/configuration/global-configuration/command-line-arguments.md#cmdoption-allow-empty-ingress-host" >}}) is enabled, multiple Ingress resources without a `host` also constitute a host collision for the default server slot. NGINX Ingress Controller has two strategies for handling host collisions:
 
 - Choosing a single "winner" resource to handle the host.
 - Merging the configuration of the conflicting resources.

@@ -169,8 +169,8 @@ The table below summarizes the available annotations.
 
 | Annotation | ConfigMap Key | Description | Default |
 | ---| ---| ---| ---|
-| *nginx.org/listen-ports* | N/A | Configures HTTP ports that NGINX will listen on. | *[80]* |
-| *nginx.org/listen-ports-ssl* | N/A | Configures HTTPS ports that NGINX will listen on. | *[443]* |
+| *nginx.org/listen-ports* | N/A | Configures HTTP ports that NGINX will listen on. Not supported on Ingress resources without a `host`; use the `-default-http-listener-port` command-line argument instead. | *[80]* |
+| *nginx.org/listen-ports-ssl* | N/A | Configures HTTPS ports that NGINX will listen on. Not supported on Ingress resources without a `host`; use the `-default-https-listener-port` command-line argument instead. | *[443]* |
 
 ### Backend services (Upstreams)
 

@@ -80,7 +80,8 @@ Starting from Kubernetes 1.18, you can use the following new features:
 
 NGINX Ingress Controller imposes the following restrictions on Ingress resources:
 
-- When defining an Ingress resource, the `host` field is required.
+- The `host` field is required by default. To allow Ingress resources to omit the `host` field, use the [`-allow-empty-ingress-host`]({{< ref "/nic/configuration/global-configuration/command-line-arguments.md#cmdoption-allow-empty-ingress-host" >}}) command-line argument.
+- When `-allow-empty-ingress-host` is enabled, `spec.tls` is not supported on Ingress resources without a `host`. To configure TLS, use the [`-default-server-tls-secret`]({{< ref "/nic/configuration/global-configuration/command-line-arguments.md#cmdoption-default-server-tls-secret" >}}) command-line argument instead.
 - The `host` value needs to be unique among all Ingress and VirtualServer resources unless the Ingress resource is a [mergeable minion]({{< ref "/nic/configuration/ingress-resources/cross-namespace-configuration.md" >}}). View the [Host and Listener collisions]({{< ref "/nic/configuration/host-and-listener-collisions.md" >}}) topic for more information.
 - The `path` field in `spec.rules[].http.paths[]` is required for `Exact` and `Prefix` `pathTypes`.
 - The ImplementationSpecific `pathType` is treated as equivalent to `Prefix` `pathType`, with the exception that when this `pathType` is configured, the `path` field in `spec.rules[].http.paths[]` is not mandatory. `path` defaults to `/` if not set but the `pathType` is set to ImplementationSpecific.

@@ -9,6 +9,6 @@ nd-docs: DOCS-594
 
 This topic explains how to spread Ingress configuration across different namespaces in F5 NGINX Ingress Controller.
 
-You can spread the Ingress configuration for a common host across multiple Ingress resources using Mergeable Ingress resources. Such resources can belong to the *same* or *different* namespaces. This enables easier management when using a large number of paths. See the [Mergeable Ingress Resources](https://github.com/nginx/kubernetes-ingress/tree/v{{< nic-version >}}/examples/ingress-resources/mergeable-ingress-types) example in our GitHub repo.
+You can spread the Ingress configuration for a common host across multiple Ingress resources using Mergeable Ingress resources. Such resources can belong to the *same* or *different* namespaces. This enables easier management when using a large number of paths. See the [Mergeable Ingress Resources](https://github.com/nginx/kubernetes-ingress/tree/v{{< nic-version >}}/examples/ingress-resources/mergeable-ingress-types) example in our GitHub repo. When [`-allow-empty-ingress-host`]({{< ref "/nic/configuration/global-configuration/command-line-arguments.md#cmdoption-allow-empty-ingress-host" >}}) is enabled, this also applies to Ingress resources without a `host`.
 
 As an alternative to Mergeable Ingress resources, you can use [VirtualServer and VirtualServerRoute resources]({{< ref "/nic//configuration/virtualserver-and-virtualserverroute-resources.md" >}}) for cross-namespace configuration. See the [Cross-Namespace Configuration](https://github.com/nginx/kubernetes-ingress/tree/v{{< nic-version >}}/examples/custom-resources/cross-namespace-configuration) example in our GitHub repo.
@@ -62,7 +62,7 @@ The [values.schema.json](https://github.com/nginx/kubernetes-ingress/blob/main/c
 | **controller.customPorts** | A list of custom ports to expose on the NGINX Ingress Controller pod. Follows the conventional Kubernetes yaml syntax for container ports. | [] |
 | **controller.defaultTLS.cert** | The base64-encoded TLS certificate for the default HTTPS server. **Note:** It is recommended that you specify your own certificate. Alternatively, omitting the default server secret completely will configure NGINX to reject TLS connections to the default server. |
 | **controller.defaultTLS.key** | The base64-encoded TLS key for the default HTTPS server. **Note:** It is recommended that you specify your own key. Alternatively, omitting the default server secret completely will configure NGINX to reject TLS connections to the default server. |
-| **controller.defaultTLS.secret** | The secret with a TLS certificate and key for the default HTTPS server. The value must follow the following format: `<namespace>/<name>`. Used as an alternative to specifying a certificate and key using `controller.defaultTLS.cert` and `controller.defaultTLS.key` parameters. **Note:** Alternatively, omitting the default server secret completely will configure NGINX to reject TLS connections to the default server. | None |
+| **controller.defaultTLS.secret** | The secret with a TLS certificate and key for the default HTTPS server. The value must follow the following format: `<namespace>/<name>`. Used as an alternative to specifying a certificate and key using `controller.defaultTLS.cert` and `controller.defaultTLS.key` parameters. **Note:** Alternatively, omitting the default server secret completely will configure NGINX to reject TLS connections to the default server. When `controller.allowEmptyIngressHost` is enabled, this secret also provides TLS for Ingress resources without a `host`. | None |
 | **controller.wildcardTLS.cert** | The base64-encoded TLS certificate for every Ingress/VirtualServer host that has TLS enabled but no secret specified. If the parameter is not set, for such Ingress/VirtualServer hosts NGINX will break any attempt to establish a TLS connection. | None |
 | **controller.wildcardTLS.key** | The base64-encoded TLS key for every Ingress/VirtualServer host that has TLS enabled but no secret specified. If the parameter is not set, for such Ingress/VirtualServer hosts NGINX will break any attempt to establish a TLS connection. | None |
 | **controller.wildcardTLS.secret** | The secret with a TLS certificate and key for every Ingress/VirtualServer host that has TLS enabled but no secret specified. The value must follow the following format: `<namespace>/<name>`. Used as an alternative to specifying a certificate and key using `controller.wildcardTLS.cert` and `controller.wildcardTLS.key` parameters. | None |
@@ -190,8 +190,9 @@ The [values.schema.json](https://github.com/nginx/kubernetes-ingress/blob/main/c
 | **controller.statefulset.nginxCachePVC.storageClass** | The storage class for the persistent volume claim. Only applies when `controller.kind` is set to `statefulset`. | `""` |
 | **controller.statefulset.nginxCachePVC.accessModes** | The access modes for the persistent volume claim. Only applies when `controller.kind` is set to `statefulset`. | `["ReadWriteOnce"]` |
 | **controller.disableIPV6** | Disable IPV6 listeners explicitly for nodes that do not support the IPV6 stack. | false |
-| **controller.defaultHTTPListenerPort**  | Sets the port for the HTTP `default_server` listener. | 80 |
-| **controller.defaultHTTPSListenerPort**  | Sets the port for the HTTPS `default_server` listener. | 443 |
+| **controller.defaultHTTPListenerPort**  | Sets the port for the HTTP `default_server` listener. When `controller.allowEmptyIngressHost` is enabled, also configures the HTTP listener port for Ingress resources without a `host`. | 80 |
+| **controller.defaultHTTPSListenerPort**  | Sets the port for the HTTPS `default_server` listener. When `controller.allowEmptyIngressHost` is enabled, also configures the HTTPS listener port for Ingress resources without a `host`. | 443 |
+| **controller.allowEmptyIngressHost** | Allows Ingress resources to omit the `host` field. `spec.tls` is not supported on Ingress resources without a `host`; use `controller.defaultTLS.secret` instead. `nginx.org/listen-ports` and `nginx.org/listen-ports-ssl` annotations are not supported; use `controller.defaultHTTPListenerPort` and `controller.defaultHTTPSListenerPort` instead. | false |
 | **controller.readOnlyRootFilesystem** | Configure root filesystem as read-only and add volumes for temporary data. Three major releases after 3.5.x this argument will be moved permanently to the `controller.securityContext` section.  | false |
 | **controller.enableSSLDynamicReload** | Enable lazy loading for SSL Certificates. | true |
 | **controller.telemetryReporting.enable** | Enable telemetry reporting. | true |

@@ -312,3 +312,40 @@ Normal  ScalingReplicaSet  98s    deployment-controller  Scaled down replica set
 {{% /tab %}}
 
 {{< /tabs >}}
+
+## Custom NGINX templates
+
+If you use custom NGINX configuration templates, review and apply any upstream template changes before upgrading. For more information, see [Custom templates]({{< ref "/nic/configuration/global-configuration/custom-templates.md" >}}).
+
+{{< call-out "warning" "Upgrading to version 5.5 or later">}}
+In version 5.5, the default server block was removed from `main-template` and is now generated by `ingress-template`. You must update both templates before upgrading. If you had customizations inside the default server block in your `main-template`, the patch will remove them. Migrate those changes to your `ingress-template` manually.
+{{< /call-out >}}
+
+1. Clone the repository:
+
+   ```shell
+   git clone https://github.com/nginx/kubernetes-ingress.git
+   ```
+
+2. Generate a diff between the version you are upgrading from and the version you are upgrading to. For `main-template` and `ingress-template`, use `version1`. For `virtualserver-template` and `transportserver-template`, use `version2`:
+
+   ```shell
+   git diff v<current-version>..v<target-version> -- internal/configs/version1/<template-file> > upstream.patch
+   git diff v<current-version>..v<target-version> -- internal/configs/version2/<template-file> > upstream.patch
+   ```
+
+3. Extract your custom template from the ConfigMap to a local file. The valid key names are `main-template`, `ingress-template`, `virtualserver-template`, and `transportserver-template`:
+
+   ```shell
+   kubectl get configmap <name> -n nginx-ingress -o jsonpath='{.data.<template-key>}' > my-template.tmpl
+   ```
+
+4. Apply the patch to your custom template:
+
+   ```shell
+   patch my-template.tmpl < upstream.patch
+   ```
+
+   If the patch fails to apply some changes, review the rejected changes in `my-template.tmpl.rej` and apply them by manually.
+
+5. Update the template key with the patched content. If you manage your ConfigMap directly, update the relevant key in your manifest and run `kubectl apply -f <your-configmap.yaml>`. If you use Helm, set the key under `controller.config.entries` in your values file and run `helm upgrade`.