docs: added documentation for Agent deployment on GKE cluster

docs/deploy/gke.md

@@ -39,11 +39,11 @@ And copy the project number from the output.
 export GOOGLE_CLOUD_PROJECT_NUMBER=YOUR_PROJECT_NUMBER
 ```
 
-## Deployment commands
+## Deployment options
 
-### gcloud CLI
+### Option 1: Manual Deployment using gcloud and kubectl
 
-You can deploy your agent to GKE using the `gcloud` and `kubectl` cli and Kubernetes manifest files.
+You can deploy your agent to GKE either **manually using Kubernetes manifests** or **automatically using the `adk deploy gke` command**. Choose the approach that best suits your workflow.
 
 Ensure you have authenticated with Google Cloud (`gcloud auth login` and `gcloud config set project <your-project-id>`).
 
@@ -58,6 +58,7 @@ gcloud services enable \
     cloudbuild.googleapis.com \
     aiplatform.googleapis.com
 ```
+### Option 1: Manual Deployment using gcloud and kubectl
 
 ### Create a GKE cluster
 
@@ -304,6 +305,98 @@ You can get the external IP address of your service using:
 kubectl get svc adk-agent -o=jsonpath='{.status.loadBalancer.ingress[0].ip}'
 ```
 
+### Option 2: Automated Deployment using `adk deploy gke`
+
+ADK provides a CLI command to streamline GKE deployment. This avoids the need to manually build images, write Kubernetes manifests, or push to Artifact Registry.
+
+#### Prerequisites
+
+Before you begin, ensure you have the following set up:
+
+1. **A running GKE cluster:** You need an active Kubernetes cluster on Google Cloud.
+
+2. **`gcloud` CLI:** The Google Cloud CLI must be installed, authenticated, and configured to use your target project. Run `gcloud auth login` and `gcloud config set project [YOUR_PROJECT_ID]`.
+
+3. **Required IAM Permissions:** The user or service account running the command needs, at a minimum, the following roles:
+
+   * **Kubernetes Engine Developer** (`roles/container.developer`): To interact with the GKE cluster.
+
+   * **Artifact Registry Writer** (`roles/artifactregistry.writer`): To push the agent's container image.
+
+4. **Docker:** The Docker daemon must be running on your local machine to build the container image.
+
+### The `deploy gke` Command
+
+The command takes the path to your agent and parameters specifying the target GKE cluster.
+
+#### Syntax
+
+```bash
+adk deploy gke [OPTIONS] AGENT_PATH
+```
+
+### Arguments & Options
+
+| Argument    | Description | Required |
+| -------- | ------- | ------  |
+| AGENT_PATH  | The local file path to your agent's root directory.    |Yes |
+| --project | The Google Cloud Project ID where your GKE cluster is located.     | Yes | 
+| --cluster_name   | The name of your GKE cluster.    | Yes |
+| --region    | The Google Cloud region of your cluster (e.g., us-central1).    | Yes |
+| --with_ui   | Deploys both the agent's back-end API and a companion front-end user interface.    | No |
+| --verbosity   | Sets the logging level for the deployment process. Options: debug, info, warning, error.     | No |
+
+
+### How It Works
+When you run the `adk deploy gke` command, the ADK performs the following steps automatically:
+
+- Containerization: It builds a Docker container image from your agent's source code.
+
+- Image Push: It tags the container image and pushes it to your project's Artifact Registry.
+
+- Manifest Generation: It dynamically generates the necessary Kubernetes manifest files (a `Deployment` and a `Service`).
+
+- Cluster Deployment: It applies these manifests to your specified GKE cluster, which triggers the following:
+
+The `Deployment` instructs GKE to pull the container image from Artifact Registry and run it in one or more Pods.
+
+The `Service` creates a stable network endpoint for your agent. By default, this is a LoadBalancer service, which provisions a public IP address to expose your agent to the internet.
+
+
+### Example Usage
+Here is a practical example of deploying an agent located at `~/agents/multi_tool_agent/` to a GKE cluster named test.
+
+```bash
+adk deploy gke \
+    --project myproject \
+    --cluster_name test \
+    --region us-central1 \
+    --with_ui \
+    --verbosity info \
+    ~/agents/multi_tool_agent/
+```
+
+### Verifying Your Deployment
+If you used `adk deploy gke`, verify the deployment using `kubectl`:
+
+1. Check the Pods: Ensure your agent's pods are in the Running state.
+
+```bash
+kubectl get pods
+```
+You should see output like `adk-default-service-name-xxxx-xxxx ... 1/1 Running` in the default namespace.
+
+2. Find the External IP: Get the public IP address for your agent's service.
+
+```bash
+kubectl get service
+NAME                       TYPE           CLUSTER-IP      EXTERNAL-IP     PORT(S)        AGE
+adk-default-service-name   LoadBalancer   34.118.228.70   34.63.153.253   80:32581/TCP   5d20h
+```
+
+We can navigate to the external IP and interact with the agent via UI
+![alt text](../assets/agent-gke-deployment.png)
+
 ## Testing your agent
 
 Once your agent is deployed to GKE, you can interact with it via the deployed UI (if enabled) or directly with its API endpoints using tools like `curl`. You'll need the service URL provided after deployment.