Platform Architecture

The SRE Portfolio platform runs on a production-grade Kubernetes cluster provisioned via Terraform on Google Cloud Platform. This page details the infrastructure, deployment pipeline, and observability stack.

1. Cloud Infrastructure (GKE)

The foundation is a GKE Autopilot cluster running in a custom VPC. All infrastructure is managed as code (IaC) using Terraform.

Architecture Diagram

graph TB
    subgraph GCP["Google Cloud Platform (Asia-South1)"]
        subgraph VPC["sre-platform-vpc"]
            subgraph Subnet["sre-platform-subnet"]
                GKE["GKE Autopilot Cluster"]
                Ingress["Ingress (HTTPS)"]
                
                subgraph Nodes["Cluster Nodes"]
                    API["api-service (Go)"]
                    Worker["worker-service (Go)"]
                    Redis["redis (Cache)"]
                end
            end
        end
        DNS["Cloud DNS (sanjeevsethi.in)"] --> Ingress
        GCR["Artifact Registry"] -.-> |Pulls Images| Nodes
    end

Key Decisions

• GKE Autopilot: Selected for zero-overhead node management and built-in security best practices.
• Terraform State: Stored remotely in GCS buckets for team collaboration and lock safety.
• Network: Complete VPC isolation with minimal public exposure.

2. CI/CD Pipeline

We follow GitOps principles where possible. Deployment is automated via GitHub Actions.

graph LR
    Dev[Developer] -->|git push| GitHub[GitHub Repo]
    GitHub -->|Trigger| Actions[GitHub Actions]
    
    subgraph CI["Continuous Integration"]
        Actions -->|Test| GoTest["Go Test & Vet"]
        GoTest -->|Build| DockerBuild["Docker Build"]
        DockerBuild -->|Push| GCR["Artifact Registry"]
    end
    
    subgraph CD["Continuous Deployment"]
        GCR -->|Deploy| Helm["Helm Upgrade"]
        Helm -->|Release| GKE["GKE Cluster"]
    end

Pipeline Steps

1. Test: Runs go test ./... and go vet to ensure code quality.
2. Build: Builds multi-stage Docker images (optimized using distroless base).
3. Publish: Pushes tagged images to Google Artifact Registry.
4. Deploy: Uses Helm to upgrade the application on GKE, ensuring zero-downtime rolling updates.

3. Observability Stack

The platform implements the three pillars of observability:

• Metrics: Prometheus (Google Managed) scrapes endpoints. Grafana visualizes Golden Signals (Latency, Traffic, Errors, Saturation).
• Logs: Structured JSON logging (Zerolog) with correlation IDs.
• Traces: OpenTelemetry (OTel) instrumentation for end-to-end request tracing.