Microservice (`service`)

The service workload equips developers to build high-throughput, cloud-native microservices and distributed APIs.

Powered by packages/cloud/service, packages/sec, and packages/resilience, the service workload includes production-grade discovery, distributed tracing, gateway routing, and telemetry out of the box.

Architectural Characteristics

Service Discovery: Native drivers for Consul, etcd, Kubernetes DNS, and AWS Cloud Map.
Telemetry & Observability: Built-in OpenTelemetry (OTel) instrumentation for distributed tracing, metrics, and structured logging with W3C traceparent propagation.
Traffic Resilience: Token-bucket rate limiting, circuit breakers, timeout propagation, and concurrency bulkheads.
Health & Liveness Check Probes: Automatic /healthz and /readyz endpoints adhering to cloud container conventions.

Scaffolding a `service` Project

kiw new auth-service --service
cd auth-service

Directory layout:

auth-service/
├── krewire.yaml          # Project configuration
├── go.mod
├── cmd/
│   └── service/
│       └── main.go       # Service entry point
└── internal/
    ├── api/              # HTTP / gRPC endpoint handlers
    ├── discovery/        # Service registration logic
    └── domain/           # Core domain business logic

Service Implementation

package main

import (
	"context"
	"net/http"
	"os"
	"time"

	"github.com/krewire/krewire/packages/cloud/service"
	"github.com/krewire/krewire/packages/web"
)

func main() {
	svc := service.New(service.Config{
		Name:    "auth-service",
		Version: "0.1.0",
		Port:    ":8080",
	})

	router := web.NewRouter()

	// Health and readiness endpoints
	router.Get("/healthz", service.HealthHandler())
	router.Get("/readyz", service.ReadinessHandler())

	// Protected business route
	router.Post("/v1/tokens/verify", func(w http.ResponseWriter, r *http.Request) {
		web.JSON(w, http.StatusOK, map[string]any{
			"valid":     true,
			"verified": time.Now().UTC(),
		})
	})

	// Start service with automated discovery registration
	if err := svc.Start(context.Background(), router); err != nil {
		os.Exit(1)
	}
}

Configuration (`krewire.yaml`)

project:
  name: "auth-service"
  kind: service
  version: "0.1.0"

service:
  port: "8080"
  discovery:
    provider: "kubernetes" # consul, etcd, kubernetes, static
    service_name: "auth-service"
  rate_limit:
    requests_per_second: 1000
    burst: 200
  telemetry:
    endpoint: "otel-collector:4317"

Running and Verifying

Run the service locally:

kiw run

Inspect registered endpoints and service health status:

curl http://localhost:8080/healthz

Microservice (service)