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:

Dockerfile (recommended for most apps):

# Multi-stage build for smaller, more secure images
FROM golang:1.22 AS builder
WORKDIR /app
COPY . .
RUN CGO_ENABLED=0 go build -o server .

FROM gcr.io/distroless/static:nonroot
COPY --from=builder /app/server /server
USER nonroot:nonroot
EXPOSE 8080
ENTRYPOINT ["/server"]

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

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:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
  namespace: default
spec:
  replicas: 2
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
      - name: my-app
        image: <REGION>-docker.pkg.dev/<PROJECT>/<REPO>/<IMAGE>:<TAG>
        ports:
        - containerPort: 8080
        resources:
          requests:
            cpu: "250m"
            memory: "256Mi"
          limits:
            cpu: "500m"
            memory: "512Mi"
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
          initialDelaySeconds: 10
        readinessProbe:
          httpGet:
            path: /readyz
            port: 8080
          initialDelaySeconds: 5
---
apiVersion: v1
kind: Service
metadata:
  name: my-app
spec:
  selector:
    app: my-app
  ports:
  - port: 80
    targetPort: 8080
  type: ClusterIP

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)

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

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