GKE Preview Security Checklist - MCP Server with LangGraph

This checklist helps verify that your GKE preview environment follows security best practices.

Network Security

VPC Isolation

Preview uses a separate VPC from production
VPC has custom subnets (not default VPC)
VPC flow logs are enabled
Private Google Access is enabled for GKE subnet

Verification:

## List VPCs
gcloud compute networks list

## Check subnet configuration
gcloud compute networks subnets describe preview-gke-subnet \
  --region=us-central1 \
  --format=yaml

GKE Cluster Security

Private nodes are enabled (no public IPs)
Master authorized networks configured (if needed)
Control plane is on a private endpoint OR restricted public endpoint
Workload Identity is enabled
Shielded nodes are enabled
Binary Authorization is enabled

Verification:

## Check cluster configuration
gcloud container clusters describe preview-mcp-server-langgraph-gke \
  --region=us-central1 \
  --format=yaml

## Verify private nodes
gcloud container clusters describe preview-mcp-server-langgraph-gke \
  --region=us-central1 \
  --format='value(privateClusterConfig.enablePrivateNodes)'

## Verify Workload Identity
gcloud container clusters describe preview-mcp-server-langgraph-gke \
  --region=us-central1 \
  --format='value(workloadIdentityConfig.workloadPool)'

## Verify Binary Authorization
gcloud container clusters describe preview-mcp-server-langgraph-gke \
  --region=us-central1 \
  --format='value(binaryAuthorization.evaluationMode)'

Network Policies

Default deny-all ingress policy exists
Egress policies restrict outbound traffic
Pod-to-pod communication is restricted
Metadata service (169.254.169.254) is blocked

Verification:

## List network policies
kubectl get networkpolicies -n preview-mcp-server-langgraph

## Check specific policies
kubectl describe networkpolicy default-deny-ingress -n preview-mcp-server-langgraph
kubectl describe networkpolicy allow-egress -n preview-mcp-server-langgraph

Firewall Rules

VPC firewall rules follow least privilege
No overly permissive rules (0.0.0.0/0)
SSH access restricted to IAP (35.235.240.0/20)

Verification:

## List firewall rules for preview VPC
gcloud compute firewall-rules list --filter="network:preview-vpc"

Identity & Access Management (IAM)

Service Accounts

Pods use Workload Identity (not service account keys)
Each component has its own service account
Service accounts follow least privilege principle
No service account keys are used

Verification:

## Check service account IAM bindings
gcloud iam service-accounts get-iam-policy \
  mcp-preview-sa@vishnu-sandbox-20250310.iam.gserviceaccount.com

## Verify no keys exist
gcloud iam service-accounts keys list \
  --iam-account=mcp-preview-sa@vishnu-sandbox-20250310.iam.gserviceaccount.com

Workload Identity

Kubernetes service account is annotated with GCP SA
GCP service account has workloadIdentityUser binding
Pods successfully authenticate without keys

Verification:

## Check K8s service account annotation
kubectl describe sa mcp-server-langgraph -n preview-mcp-server-langgraph | grep iam.gke.io

## Test Workload Identity from pod
kubectl run -it --rm test \
  --image=google/cloud-sdk:slim \
  --serviceaccount=mcp-server-langgraph \
  --namespace=preview-mcp-server-langgraph \
  -- gcloud auth list

GitHub Actions Workload Identity Federation

Workload Identity Pool created
OIDC provider configured for GitHub
No service account keys in GitHub Secrets
Repository condition restricts access

Verification:

## Check Workload Identity Pool
gcloud iam workload-identity-pools describe github-actions-pool \
  --location=global

## Check provider configuration
gcloud iam workload-identity-pools providers describe github-provider \
  --location=global \
  --workload-identity-pool=github-actions-pool

Secrets Management

Secret Manager

All secrets stored in Secret Manager (not Kubernetes secrets)
Secrets have automatic replication
Service account has only secretAccessor role
No plaintext secrets in code or configs

Verification:

## List preview secrets
gcloud secrets list --filter="name:preview-*"

## Verify permissions
gcloud secrets get-iam-policy preview-jwt-secret

External Secrets Operator

External Secrets Operator installed
SecretStore configured with Workload Identity
ExternalSecret syncing successfully
Kubernetes secrets are created/updated

Verification:

## Check ESO is running
kubectl get pods -n external-secrets-system

## Check ExternalSecret status
kubectl get externalsecret mcp-preview-secrets -n preview-mcp-server-langgraph

## Verify secrets are synced
kubectl get secret mcp-preview-secrets -n preview-mcp-server-langgraph

Container Security

Image Security

Images are signed/attested
Binary Authorization policy enforces signed images
Images come from trusted registry (Artifact Registry)
Images use minimal base (distroless)

Verification:

## Check image source
kubectl get deployment preview-mcp-server-langgraph -n preview-mcp-server-langgraph \
  -o jsonpath='{.spec.template.spec.containers[0].image}'

## Check Binary Authorization policy
gcloud container binauthz policy export

Pod Security

Verification:

## Check pod security context
kubectl get pod -n preview-mcp-server-langgraph -o json | \
  jq '.items[].spec.securityContext'

## Check for privileged containers
kubectl get pods -n preview-mcp-server-langgraph -o json | \
  jq '.items[].spec.containers[] | select(.securityContext.privileged == true)'

Cloud SQL Proxy Sidecar

Cloud SQL proxy runs as non-root user
Proxy uses private IP connection
Proxy container has resource limits
Application connects via localhost (127.0.0.1)

Verification:

## Check Cloud SQL proxy container
kubectl get pod -n preview-mcp-server-langgraph -o json | \
  jq '.items[].spec.containers[] | select(.name == "cloud-sql-proxy")'

Data Security

Encryption

Data at rest encryption enabled (GKE default)
Secrets encrypted in etcd
Cloud SQL uses encrypted connections
Redis uses TLS (if enabled)

Verification:

## GKE encryption is automatic, verify cluster exists
kubectl cluster-info

## Check Cloud SQL instance encryption
gcloud sql instances describe mcp-preview-postgres \
  --format='value(diskEncryptionStatus.kmsKeyName)'

Database Security

Cloud SQL uses private IP (not public)
Database passwords are in Secret Manager
Database users follow least privilege
Automatic backups are enabled

Verification:

## Check Cloud SQL IP configuration
gcloud sql instances describe mcp-preview-postgres \
  --format='value(ipAddresses[])'

## Check backup configuration
gcloud sql instances describe mcp-preview-postgres \
  --format='value(settings.backupConfiguration)'

Redis Security

Redis uses private IP
AUTH is enabled
Redis password is in Secret Manager
Automatic failover enabled (standard tier)

Verification:

## Check Redis configuration
gcloud redis instances describe mcp-preview-redis \
  --region=us-central1

## Verify AUTH is enabled
gcloud redis instances describe mcp-preview-redis \
  --region=us-central1 \
  --format='value(authEnabled)'

Monitoring & Logging

Cloud Logging

Container logs sent to Cloud Logging
Audit logs enabled
Log retention configured
No sensitive data in logs

Verification:

## Check recent logs
gcloud logging read \
  "resource.type=k8s_container
   resource.labels.cluster_name=preview-mcp-server-langgraph-gke" \
  --limit=10 \
  --format=json

## Check audit logs are enabled
gcloud logging logs list --filter="logName:cloudaudit.googleapis.com"

Cloud Monitoring

Metrics are being collected
Alert policies configured
Uptime checks configured
Dashboards created

Verification:

## List metrics
gcloud monitoring metrics-descriptors list \
  --filter="metric.type:kubernetes.io/container/*" \
  --limit=10

## List alert policies
gcloud alpha monitoring policies list

Cloud Trace

Distributed tracing enabled
Traces sent to Cloud Trace
Sampling rate configured

Verification:

## This is configured in OTel collector, check collector logs
kubectl logs -n preview-mcp-server-langgraph -l app=otel-collector

Compliance & Governance

Resource Labeling

All resources have environment label
Cost allocation labels applied
Owner/team labels present

Verification:

## Check GKE cluster labels
gcloud container clusters describe preview-mcp-server-langgraph-gke \
  --region=us-central1 \
  --format='value(resourceLabels)'

## Check pods have labels
kubectl get pods -n preview-mcp-server-langgraph --show-labels

Resource Limits

All containers have resource requests
All containers have resource limits
Namespace has ResourceQuota
LimitRange configured

Verification:

## Check container resources
kubectl get pods -n preview-mcp-server-langgraph -o json | \
  jq '.items[].spec.containers[] | {name: .name, resources: .resources}'

## Check ResourceQuota
kubectl get resourcequota -n preview-mcp-server-langgraph

## Check LimitRange
kubectl get limitrange -n preview-mcp-server-langgraph

Backup & Disaster Recovery

Cloud SQL automated backups enabled
Kubernetes manifests in version control
Secrets can be recovered from Secret Manager
Recovery procedure documented

Verification:

## Check backup configuration
gcloud sql instances describe mcp-preview-postgres \
  --format='value(settings.backupConfiguration.enabled)'

## List backups
gcloud sql backups list --instance=mcp-preview-postgres

GitHub Actions Security

Workflow Security

Workload Identity Federation used (no keys)
Workflows use specific versions (not @latest)
GitHub Environment protection rules configured
Approval required before deployment
Secrets are GitHub Secrets (not hardcoded)

Verification:

Review .github/workflows/deploy-preview-gke.yaml
Check GitHub repository settings → Environments → preview

Deployment Validation

Smoke tests run post-deployment
Health checks pass before marking success
Automatic rollback on failure
Deployment creates audit trail

Verification:

## Check recent deployments in Cloud Console
gcloud container clusters get-credentials preview-mcp-server-langgraph-gke --region=us-central1
kubectl rollout history deployment/preview-mcp-server-langgraph -n preview-mcp-server-langgraph

Security Scanning

Vulnerability Scanning

Container images scanned for vulnerabilities
No HIGH or CRITICAL vulnerabilities
Scanning integrated into CI/CD
Scan results reviewed regularly

Verification:

## Enable Container Analysis API if not already
gcloud services enable containeranalysis.googleapis.com

## Scan image
gcloud artifacts docker images scan \
  us-central1-docker.pkg.dev/vishnu-sandbox-20250310/mcp-preview/agent:preview-latest

Security Auditing

Regular security audits scheduled
Audit findings tracked and remediated
Compliance requirements documented

Incident Response

Monitoring & Alerting

Alert policies configured for security events
On-call rotation defined
Incident response playbook exists
Runbooks for common issues

Rollback Procedures

Documented rollback procedure
Rollback tested in preview
Automatic rollback configured in CI/CD

Test Rollback:

## Manual rollback test
kubectl rollout undo deployment/preview-mcp-server-langgraph -n preview-mcp-server-langgraph
kubectl rollout status deployment/preview-mcp-server-langgraph -n preview-mcp-server-langgraph

Scoring

Total Checklist Items: ~80 Security Score Calculation:

90-100% complete: Excellent - Production-ready security posture
80-89% complete: Good - Minor improvements needed
70-79% complete: Fair - Significant gaps exist
<70% complete: Poor - Not ready for production-like preview

Next Steps

After completing this checklist:

Document exceptions: Some items may not apply to your use case - document why
Remediate failures: Fix any failing checks before deploying to production
Schedule regular reviews: Re-run this checklist quarterly
Automate checks: Convert manual checks to automated tests where possible

​Network Security

​VPC Isolation

​GKE Cluster Security

​Network Policies

​Firewall Rules

​Identity & Access Management (IAM)

​Service Accounts

​Workload Identity

​GitHub Actions Workload Identity Federation

​Secrets Management

​Secret Manager

​External Secrets Operator

​Container Security

​Image Security

​Pod Security

​Cloud SQL Proxy Sidecar

​Data Security

​Encryption

​Database Security

​Redis Security

​Monitoring & Logging

​Cloud Logging

​Cloud Monitoring

​Cloud Trace

​Compliance & Governance

​Resource Labeling

​Resource Limits

​Backup & Disaster Recovery

​GitHub Actions Security

​Workflow Security

​Deployment Validation

​Security Scanning

​Vulnerability Scanning

​Security Auditing

​Incident Response

​Monitoring & Alerting

​Rollback Procedures

​Scoring

​Next Steps

​Resources

Network Security

VPC Isolation

GKE Cluster Security

Network Policies

Firewall Rules

Identity & Access Management (IAM)

Service Accounts

Workload Identity

GitHub Actions Workload Identity Federation

Secrets Management

Secret Manager

External Secrets Operator

Container Security

Image Security

Pod Security

Cloud SQL Proxy Sidecar

Data Security

Encryption

Database Security

Redis Security

Monitoring & Logging

Cloud Logging

Cloud Monitoring

Cloud Trace

Compliance & Governance

Resource Labeling

Resource Limits

Backup & Disaster Recovery

GitHub Actions Security

Workflow Security

Deployment Validation

Security Scanning

Vulnerability Scanning

Security Auditing

Incident Response

Monitoring & Alerting

Rollback Procedures

Scoring

Next Steps

Resources