(Feat): Initial Commit

internal/api/handlers/common/get_healthy.go

@@ -0,0 +1,55 @@
+// nolint:revive
+package common
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"allaboutapps.dev/aw/go-starter/internal/api"
+	"github.com/labstack/echo/v4"
+)
+
+const (
+	// We use 521 to indicate an error state
+	// same as Cloudflare: https://support.cloudflare.com/hc/en-us/articles/115003011431#521error
+	httpStatusDown = 521
+)
+
+func GetHealthyRoute(s *api.Server) *echo.Route {
+	return s.Router.Management.GET("/healthy", getHealthyHandler(s))
+}
+
+// Heathly check (= liveness)
+// Returns an human readable string about the current service status.
+// In addition to readiness probes, it performs actual write probes.
+// Note that /-/healthy is private (shielded by the mgmt-secret) as it may expose sensitive information about your service.
+// Structured upon https://prometheus.io/docs/prometheus/latest/management_api/
+func getHealthyHandler(s *api.Server) echo.HandlerFunc {
+	return func(c echo.Context) error {
+		if !s.Ready() {
+			return c.String(httpStatusDown, "Not ready.")
+		}
+
+		var str strings.Builder
+		fmt.Fprintln(&str, "Ready.")
+
+		// General Timeout and associated context.
+		ctx, cancel := context.WithTimeout(c.Request().Context(), s.Config.Management.LivenessTimeout)
+		defer cancel()
+
+		healthyStr, errs := ProbeLiveness(ctx, s.DB, s.Config.Management.ProbeWriteablePathsAbs, s.Config.Management.ProbeWriteableTouchfile)
+		str.WriteString(healthyStr)
+
+		// Finally return the health status according to the seen states
+		if ctx.Err() != nil || len(errs) != 0 {
+			fmt.Fprintln(&str, "Probes failed.")
+			return c.String(httpStatusDown, str.String())
+		}
+
+		fmt.Fprintln(&str, "Probes succeeded.")
+
+		return c.String(http.StatusOK, str.String())
+	}
+}