/gke-app-onboarding

GKE App Onboarding

This reference provides workflows for containerizing and deploying applications to GKE for the first time.

MCP Tools: apply_k8s_manifest, get_k8s_resource, get_k8s_rollout_status, get_k8s_logs, describe_k8s_resource

Workflow

1. App Assessment

Before containerizing, assess the application:

• Language & Framework: Identify the tech stack
• Dependencies: List required libraries and external services
• Configuration: How is the app configured? (env vars, config files, secrets)
• Statefulness: Does it need persistent storage? (databases, file storage)
• Networking: Port mapping and protocol (HTTP, gRPC, TCP)
• Health endpoints: Does the app expose health check endpoints?

2. Containerization

Create a container image. A Dockerfile with a multi-stage build is recommended for most apps — see the Go Dockerfile in references/go-example.md for a worked example.

Best practices:

• Use multi-stage builds to keep production images small
• Use distroless or minimal base images to reduce attack surface
• Run as non-root user
• Log to stdout and stderr for Cloud Logging collection

A complete worked Node.js example is provided in assets/: Dockerfile (non-root node user), index.js (implements distinct /healthz and /readyz endpoints), package.json, and deployment.yaml (hardened Deployment plus ClusterIP Service, probes wired to /healthz and /readyz).

For applications where writing a Dockerfile is not preferred, you can use Cloud Native Buildpacks to automatically detect the language and build a container image:

pack build <image> --builder gcr.io/buildpacks/builder:latest

3. Image Management

Build and store the container image:

# Configure Docker for Artifact Registry
gcloud auth configure-docker <REGION>-docker.pkg.dev --quiet

# Build and push
docker build -t <REGION>-docker.pkg.dev/<PROJECT>/<REPO>/<IMAGE>:<TAG> .
docker push <REGION>-docker.pkg.dev/<PROJECT>/<REPO>/<IMAGE>:<TAG>

Vulnerability scanning: Enable automatic scanning in Artifact Registry to detect issues in base images and dependencies.

# Check scan results
gcloud artifacts docker images describe \
  <REGION>-docker.pkg.dev/<PROJECT>/<REPO>/<IMAGE>:<TAG> \
  --show-package-vulnerability \
  --quiet

4. Manifest Generation

Generate Kubernetes manifests for the application. A baseline Deployment + ClusterIP Service manifest (probes, resource requests/limits, 2 replicas) is in references/go-example.md.

Checklist for manifests:

• Resource requests and limits set
• Liveness and readiness probes configured
• At least 2 replicas for production
• Service type appropriate (ClusterIP for internal, use Gateway API for external)

See assets/deployment.yaml for a hardened worked example. A production-hardened pod spec must include ALL of: runAsNonRoot: true, readOnlyRootFilesystem: true, allowPrivilegeEscalation: false, capabilities.drop: ["ALL"], seccompProfile: {type: RuntimeDefault}, automountServiceAccountToken: false (unless the pod needs the token — then say why), resource requests, digest-pinned image, and a ClusterIP Service.

That checklist is the baseline for any pod spec produced here. For manifest work beyond it — Gateway API routes, GCS FUSE and secret volume mounting, subPath overlays, Spot VM targeting, or AI/inference serving specs — see gke-manifest-generation.

5. Deploy

# MCP (preferred)
apply_k8s_manifest(parent="projects/<PROJECT>/locations/<REGION>/clusters/<CLUSTER>", yamlManifest="<manifest>")

# Verify
get_k8s_rollout_status(parent="...", resourceType="deployment", name="my-app")
get_k8s_resource(parent="...", resourceType="pod", labelSelector="app=my-app")

kubectl fallback:

kubectl apply -f manifests/
kubectl rollout status deployment/my-app
kubectl get pods -l app=my-app

Golden Path Onboarding Checklist

For every production application onboarding to GKE:

1. Container Security: Non-root user (runAsNonRoot: true), lockfile install, minimal/distroless base image.
2. Resource Requests: Explicit CPU and memory requests (mandatory for GKE Autopilot).
3. Health Probes: Both liveness (livenessProbe) and readiness (readinessProbe) probes configured.
4. Reliability & Availability: At least 2 replicas and a PodDisruptionBudget (minAvailable: 1 or 2).
5. IAM & Workload Identity: Workload Identity (iam.gke.io/gcp-service-account) instead of static service account keys.

Next Steps

Once the application is running on GKE:

• Configure autoscaling — see the gke-workload-scaling skill
• Set up observability — see the gke-observability skill
• Harden security — see the gke-workload-security skill
• Configure reliability (PDBs, topology spread) — see the gke-reliability skill