Add upgrading to 4.x docs

site/content/installation/installing-nic/create-license-secret.md

@@ -17,10 +17,13 @@ The JWT is required for validating your subscription and reporting telemetry dat
 
 {{< note >}} Read the [subscription licenses topic](https://docs.nginx.com/solutions/about-subscription-licenses/#for-internet-connected-environments) for a list of IPs associated with F5's licensing endpoint (`product.connect.nginx.com`). {{</ note >}}
 
-## Set up the JWT
+## Set up your NGINX Plus license 
 
+### Download the JWT
 {{< include "installation/download-jwt.md" >}}
 
+### Create the Secret 
+
 The JWT needs to be configured before deploying NGINX Ingress Controller. The JWT will be stored in a Kubernetes Secret of type `nginx.com/license`, and can be created with the following command.
 
 ```shell
@@ -63,9 +66,9 @@ For detailed guidance on creating the Management ConfigMap, refer to the [Manage
 
 ### Reports for NGINX Instance Manager {#nim}
 
-If you are deploying NGINX Ingress Controller in an "air-gapped" environment you will need to report to NGINX Instance Manager (NIM) instead of the default licensing endpoint.
+If you are deploying NGINX Ingress Controller in an "air-gapped" environment you will need to report to [NGINX Instance Manager](https://docs.nginx.com/nginx-instance-manager/) instead of the default licensing endpoint.
 
-First, you must specify the endpoint of your NGINX Instance Manager:
+First, you must specify the endpoint of your NGINX Instance Manager.
 
 {{<tabs name="nim-endpoint">}}
 

site/content/upgrading-to-v4.md

@@ -0,0 +1,92 @@
+---
+description: Guide on upgrading to v4 and above
+docs: DOCS-000
+title: Guide on upgrading to NGINX Ingress Controller 4.0.0
+toc: true
+weight: 2100
+headless: true
+---
+
+{{< note >}}
+If you are using NGINX Ingress Controller version `v3.3.2` (Helm Chart `v1.0.2`) or earlier, please upgrade to `v3.7.2` (Helm Chart `v1.4.2`), and convert your TransportServer and GlobalConfiguration resources to `apiVersion` `k8s.nginx.org/v1`.
+{{</ note >}}
+1. If using NGINX Ingress Controller custom resources with an `apiVersion` of `k8s.nginx.org/v1alpha1`, prior to upgrading to `v4.x` (Helm Chart `v2.x`) , **please ensure** that they are updated to `apiVersion: k8s.nginx.org/v1`
+{{< important >}}
+If a resource of `kind: GlobalConfiguration`, `kind: Policy` or `kind: TransportServer` is deployed as `apiVersion: k8s.nginx.org/v1alpha1`, it will be **deleted** during the upgrade process
+{{</ important >}}
+
+    Below is an example of how a Policy resource would change. Please ensure the same is done for GlobalConfiguration and TransportServer. 
+
+    {{<tabs name="resource-version-update">}}
+
+{{% comment %}} Keep this left aligned. {{% /comment %}}
+{{%tab name="Before"%}}
+
+```yaml
+apiVersion: k8s.nginx.org/v1alpha1
+kind: Policy
+metadata:
+  name: rate-limit-policy
+spec:
+  rateLimit:
+    rate: 1r/s
+    key: ${binary_remote_addr}
+    zoneSize: 10M
+```
+
+
+{{% /tab %}}
+
+{{%tab name="After"%}}
+```yaml
+apiVersion: k8s.nginx.org/v1
+kind: Policy
+metadata:
+  name: rate-limit-policy
+spec:
+  rateLimit:
+    rate: 1r/s
+    key: ${binary_remote_addr}
+    zoneSize: 10M
+```
+{{% /tab %}}
+
+    {{</tabs>}}
+
+1. Read the [Create License Secret]({{< relref "installation/installing-nic/create-license-secret">}}) topic to set up your NGINX Plus license.
+1. Usage reporting through the Cluster Connector is no longer required, and is now native to NGINX. 
+1. If your NGINX Ingress Controller installation is in an "air-gapped" environment, [usage reports can be sent to NGINX Instance Manager]({{< relref "installation/installing-nic/create-license-secret/#nim">}}). 
+1. Configure Structured Logging
+
+    {{<tabs name="structured logging">}}
+
+{{%tab name="Helm"%}}
+
+The previous Helm value `controller.logLevel` has been changed from an integer to a string. Options include: trace, debug, info, warning, error and fatal.
+
+Logs can also be rendered in different formats using the `controller.logFormat` key. Options include: glog, json and text. This only applies to NGINX Ingress Controller logs, not NGINX logs.
+
+```yaml
+controller:
+    logLevel: info
+    logFormat: json 
+```
+{{% /tab %}}
+
+{{%tab name="Manifests"%}}
+
+The command line argument `-v` has been replaced with `-log-level`. It has been changed from an integer to a string. Options include: trace, debug, info, warning, error and fatal.
+
+Logs can also be rendered in different formats using the `-log-format` command line argument. Options include: glog, json and text. This only applies to NGINX Ingress Controller logs, not NGINX logs.
+
+The command line argument `-logtostderr` has been deprecated.
+
+```yaml
+args:
+    - -log-level=info
+    - -log-format=json
+```
+
+{{% /tab %}}
+
+    {{</tabs>}}