Add GKE deployment documentation

Author: BetsyMalthus

docs/gke-deployment.md

@@ -0,0 +1,172 @@
+# Deploying sifnode on Google Kubernetes Engine (GKE)
+
+This guide walks through deploying a sifnode validator on **Google Kubernetes Engine (GKE)**.
+
+## Prerequisites
+
+| Requirement | Version | Install |
+|-------------|---------|---------|
+| gcloud CLI | latest | [Install](https://cloud.google.com/sdk/docs/install) |
+| Terraform | >= 0.13 | [Install](https://learn.hashicorp.com/tutorials/terraform/install-cli) |
+| kubectl | >= 1.18 | `gcloud components install kubectl` |
+| Helm 3 | >= 3.0 | [Install](https://helm.sh/docs/intro/install/) |
+
+## Quick Start
+
+### 1. Authenticate with GCP
+
+```bash
+gcloud auth login
+gcloud config set project YOUR_PROJECT_ID
+```
+
+### 2. Deploy Infrastructure
+
+```bash
+# Clone the repository
+git clone https://github.com/Sifchain/sifnode.git
+cd sifnode
+
+# Deploy with the automation script
+./deploy/gke/deploy_gke.sh create -p YOUR_PROJECT_ID -r us-central1
+```
+
+### 3. Verify Deployment
+
+```bash
+# Check cluster status
+./deploy/gke/deploy_gke.sh status
+
+# Check pod logs
+kubectl logs -n sifnode -l app=sifnode
+
+# Check sifnoded status
+kubectl exec -n sifnode deploy/sifnode -- sifnoded status
+```
+
+## Manual Deployment (Step by Step)
+
+### Cluster Setup
+
+```bash
+cd deploy/terraform/providers/gke
+
+terraform init
+terraform apply \
+  -var="project_id=YOUR_PROJECT_ID" \
+  -var="region=us-central1" \
+  -var="cluster_name=sifnode-gke"
+```
+
+### Configure kubectl
+
+```bash
+gcloud container clusters get-credentials sifnode-gke \
+  --region us-central1 \
+  --project YOUR_PROJECT_ID
+```
+
+### Install sifnode via Helm
+
+```bash
+# Create namespace
+kubectl create namespace sifnode
+
+# Install with GKE-specific values
+helm install sifnode deploy/helm/sifnode \
+  --namespace sifnode \
+  --create-namespace \
+  --values deploy/helm/sifnode/values_gke.yaml \
+  --set provider=gke \
+  --set persistence.storageClass=gke-ssd
+
+# Check deployment
+kubectl get pods -n sifnode -w
+```
+
+## Configuration Reference
+
+### GKE Terraform Variables
+
+| Variable | Default | Description |
+|----------|---------|-------------|
+| `project_id` | (required) | GCP project ID |
+| `region` | `us-central1` | GCP region |
+| `cluster_name` | (required) | GKE cluster name |
+| `machine_type` | `e2-standard-2` | Node machine type |
+| `desired_capacity` | `1` | Initial node count |
+| `min_capacity` | `1` | Minimum nodes (autoscaling) |
+| `max_capacity` | `5` | Maximum nodes (autoscaling) |
+| `disk_size` | `100` | Node disk size (GB) |
+| `storage_size` | `50Gi` | PVC storage size |
+| `enable_private_nodes` | `false` | Enable private GKE nodes |
+| `release_channel` | `REGULAR` | GKE release channel |
+
+### Helm Values (GKE-specific)
+
+Key settings in `values_gke.yaml`:
+
+```yaml
+provider: gke
+persistence:
+  storageClass: gke-ssd  # SSD persistent storage
+resources:
+  requests:
+    cpu: "500m"
+    memory: "1Gi"
+  limits:
+    cpu: "2"
+    memory: "4Gi"
+autoscaling:
+  enabled: true
+```
+
+## Comparison: AWS (EKS) vs GKE
+
+| Feature | AWS (EKS) | GKE |
+|---------|-----------|-----|
+| Provisioning | Terraform (terraform-aws-modules/eks) | Terraform (google_container_cluster) |
+| Node Type | t2.medium (x86) | e2-standard-2 (x86) |
+| Storage | EBS CSI / EFS CSI | GCE Persistent Disk (pd-ssd) |
+| Networking | VPC + Public Subnets | VPC + Subnet + Cloud NAT |
+| DNS | Route53 (via ExternalDNS) | Cloud DNS |
+| Ingress | ALB Ingress Controller | GCE Ingress |
+| IAM | AWS IAM Roles | GCP IAM + Workload Identity |
+| CLI Profile | AWS_PROFILE | gcloud config |
+
+## Troubleshooting
+
+### Pods stuck in Pending state
+```bash
+kubectl describe pod -n sifnode <pod-name>
+# Check for resource constraints or PVC binding issues
+```
+
+### GKE cluster not reachable
+```bash
+gcloud container clusters get-credentials sifnode-gke --region us-central1
+# Ensure your gcloud is authenticated
+```
+
+### Storage issues
+```bash
+kubectl get pvc -n sifnode
+kubectl get storageclass
+# Ensure gke-ssd storage class exists
+```
+
+## Clean Up
+
+```bash
+# Option 1: Using the deployment script
+./deploy/gke/deploy_gke.sh destroy
+
+# Option 2: Manual
+helm uninstall sifnode --namespace sifnode
+cd deploy/terraform/providers/gke
+terraform destroy -var="project_id=YOUR_PROJECT_ID"
+```
+
+---
+
+*For additional assistance, refer to the [sifnode documentation](https://docs.sifchain.finance/).*