Update kubernetes_deployment.md

fixes: kserve#383

Signed-off-by: Rajakavitha Kodhandapani <[email protected]>

Author: Rajakavitha1

docs/admin/kubernetes_deployment.md

@@ -1,52 +1,54 @@
 # Kubernetes Deployment Installation Guide
 KServe supports `RawDeployment` mode to enable `InferenceService` deployment with Kubernetes resources [`Deployment`](https://kubernetes.io/docs/concepts/workloads/controllers/deployment), [`Service`](https://kubernetes.io/docs/concepts/services-networking/service), [`Ingress`](https://kubernetes.io/docs/concepts/services-networking/ingress) and [`Horizontal Pod Autoscaler`](https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale). Comparing to serverless deployment it unlocks Knative limitations such as mounting multiple volumes, on the other hand `Scale down and from Zero` is not supported in `RawDeployment` mode.
 
-Kubernetes 1.22 is the minimally required version and please check the following recommended Istio versions for the corresponding
-Kubernetes version.
-
-## Recommended Version Matrix
-| Kubernetes Version | Recommended Istio Version |
-|:-------------------|:--------------------------|
-| 1.27               | 1.18, 1.19                |
-| 1.28               | 1.19, 1.20                |
-| 1.29               | 1.20, 1.21                |
-
-## 1. Install Istio 
-
-The minimally required Istio version is 1.13 and you can refer to the [Istio install guide](https://istio.io/latest/docs/setup/install).
-
-Once Istio is installed, create `IngressClass` resource for istio.
-```yaml
-apiVersion: networking.k8s.io/v1
-kind: IngressClass
-metadata:
-  name: istio
-spec:
-  controller: istio.io/ingress-controller
-```
-
-
-!!! note 
-    Istio ingress is recommended, but you can choose to install with other [Ingress controllers](https://kubernetes.io/docs/concepts/services-networking/ingress-controllers/) and create `IngressClass` resource for your Ingress option.
-
-
-
-## 2. Install Cert Manager
+## 1. Install Cert Manager
 The minimally required Cert Manager version is 1.9.0 and you can refer to [Cert Manager installation guide](https://cert-manager.io/docs/installation/).
 
 !!! note
     Cert manager is required to provision webhook certs for production grade installation, alternatively you can run self signed certs generation script.
 
-## 3. Install KServe
+## 2. Install KServe
 !!! note 
-    The default KServe deployment mode is `Serverless` which depends on Knative. The following step changes the default deployment mode to `RawDeployment` before installing KServe.
-
+    The default KServe deployment mode is `Serverless` which depends on Knative. The following step changes the default deployment mode to `RawDeployment` before installing KServe and the `RawDeployment` mode does not have any dependecy on Knative.
 
-**i. Install KServe**
+**i. Create a yaml file**
+Open an editor of your choice and create `kustomization.yaml` file.     
+    ```
+    apiVersion: kustomize.config.k8s.io/v1beta1
+    kind: Kustomization
+
+    namespace: kserve
+
+    resources:
+    - https://github.com/kserve/kserve/releases/download/v0.13.0/kserve.yaml
+
+    patches:
+    - target:
+        kind: ConfigMap
+        name: inferenceservice-config
+      patch: |
+        - path: /data/deploy
+          op: replace
+          value: |-
+            {
+                "defaultDeploymentMode": "RawDeployment"
+            }
+        - path: /data/ingress
+          op: replace
+          value: |-
+            {
+                "disableIstioVirtualHost": true,
+                "disableIngressCreation": true,
+                "ingressDomain": "svc.cluster.local",
+                "ingressGateway" : "disabled",
+                "ingressService" : "disabled"
+            }
+    
+**ii. Install KServe**
 
 === "kubectl"
     ```bash
-    kubectl apply -f https://github.com/kserve/kserve/releases/download/v0.13.0/kserve.yaml
+    kubectl apply -f kustomization.yaml
     ```
 
 Install KServe default serving runtimes:
@@ -55,21 +57,3 @@ Install KServe default serving runtimes:
     ```bash
     kubectl apply -f https://github.com/kserve/kserve/releases/download/v0.13.0/kserve-cluster-resources.yaml
     ```
-
-**ii. Change default deployment mode and ingress option**
-
-First in ConfigMap `inferenceservice-config` modify the `defaultDeploymentMode` in the `deploy` section,
-
-=== "kubectl"
-    ```bash
-    kubectl patch configmap/inferenceservice-config -n kserve --type=strategic -p '{"data": {"deploy": "{\"defaultDeploymentMode\": \"RawDeployment\"}"}}'
-    ```
-
-then modify the `ingressClassName` in `ingress` section to point to `IngressClass` name created in [step 1](#1-install-istio).
-    ```yaml
-    ingress: |-
-    {
-        "ingressClassName" : "your-ingress-class",
-    }
-    ```
-