add weather grpc

pkg/srv/http/http_health.go

@@ -0,0 +1,67 @@
+package http
+
+import (
+	"context"
+	"errors"
+	"math/rand"
+	"net/http"
+	"sync"
+	"time"
+
+	"github.com/rs/zerolog"
+)
+
+type HealthCheckFunc func(context.Context) error
+
+func handleHealthCheckFunc(ctx context.Context, hcFuncs ...HealthCheckFunc) func(w http.ResponseWriter, r *http.Request) {
+	// Return http handle func
+	return func(w http.ResponseWriter, r *http.Request) {
+		var (
+			healthChecksFailed bool
+			errs               error
+			hcWg               sync.WaitGroup
+		)
+
+		if len(hcFuncs) < 1 {
+			zerolog.Ctx(ctx).Warn().Msg("no health checks given responding with dummy 200")
+			hcFuncs = append(hcFuncs, dummyHealthCheck)
+		}
+
+		// Run all health check funcs concurrently
+		// log all errors
+		hcWg.Add(len(hcFuncs))
+		for _, hc := range hcFuncs {
+			go func() {
+				defer hcWg.Done()
+				errs = errors.Join(errs, hc(ctx))
+			}()
+		}
+		hcWg.Wait()
+
+		if errs != nil {
+			healthChecksFailed = true
+		}
+
+		if healthChecksFailed {
+			w.WriteHeader(http.StatusInternalServerError)
+		}
+
+		if errs != nil {
+			w.Write([]byte(errs.Error()))
+		} else {
+			w.Write([]byte("ok"))
+		}
+	}
+}
+
+func dummyHealthCheck(ctx context.Context) error {
+	workFor := rand.Intn(750)
+	ticker := time.NewTicker(time.Duration(time.Duration(workFor) * time.Millisecond))
+
+	select {
+	case <-ticker.C:
+		return nil
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+}