feat: k8s probes endpoints (#6)

Author: Swop

internal/server/handlers/k8s.go

@@ -0,0 +1,26 @@
+package handlers
+
+import (
+	"github.com/ankorstore/gh-action-mq-lease-service/internal/lease"
+	"github.com/ankorstore/gh-action-mq-lease-service/internal/storage"
+	"github.com/gofiber/fiber/v2"
+)
+
+func Liveness() func(c *fiber.Ctx) error {
+	return func(c *fiber.Ctx) error {
+		return c.SendStatus(fiber.StatusOK)
+	}
+}
+
+func Readiness(storage storage.Storage[*lease.ProviderState]) func(c *fiber.Ctx) error {
+	return func(c *fiber.Ctx) error {
+		if passed := storage.HealthCheck(c.UserContext(), func() *lease.ProviderState {
+			return lease.NewProviderState(lease.NewProviderStateOpts{
+				ID: "test-healthcheck",
+			})
+		}); !passed {
+			return c.SendStatus(fiber.StatusInternalServerError)
+		}
+		return c.SendStatus(fiber.StatusOK)
+	}
+}

internal/server/routes.go

@@ -3,6 +3,7 @@ package server
 import (
 	"github.com/ankorstore/gh-action-mq-lease-service/internal/lease"
 	"github.com/ankorstore/gh-action-mq-lease-service/internal/server/handlers"
+	"github.com/ankorstore/gh-action-mq-lease-service/internal/storage"
 	"github.com/gofiber/fiber/v2"
 )
 
@@ -14,3 +15,8 @@ func RegisterRoutes(app *fiber.App, orchestrator lease.ProviderOrchestrator) {
 	providerRoutes.Post("/release", handlers.Release(orchestrator)).Name("release")
 	providerRoutes.Get("/", handlers.ProviderDetails(orchestrator)).Name("show")
 }
+
+func RegisterK8sProbesRoutes(app *fiber.App, storage storage.Storage[*lease.ProviderState]) {
+	app.Get("/k8s/liveness", handlers.Liveness()).Name("k8s.liveness")
+	app.Get("/k8s/readiness", handlers.Readiness(storage)).Name("k8s.readiness")
+}

internal/server/server.go

@@ -141,6 +141,8 @@ func (s *serverImpl) Init() error {
 		},
 	}))
 
+	// register k8s probes handlers
+	RegisterK8sProbesRoutes(s.app, s.storage)
 	// register API routes on the fiber app
 	RegisterRoutes(s.app, s.orchestrator)
 

internal/storage/storage.go

@@ -62,6 +62,8 @@ type Storage[T object] interface {
 	// Save store the provided object in the storage
 	// the provided object should at least be able to return a non-null and unique Identifier (via the GetIdentifier() method)
 	Save(ctx context.Context, obj T) error
+	// HealthCheck verifies if the storage is connected and usable
+	HealthCheck(ctx context.Context, hydrationSample func() T) bool
 }
 
 type storageImpl[T object] struct {
@@ -149,6 +151,24 @@ func (s *storageImpl[T]) Save(ctx context.Context, obj T) error {
 	return txn.Commit()
 }
 
+// HealthCheck verifies if the storage is connected and usable
+func (s *storageImpl[T]) HealthCheck(ctx context.Context, hydrationSample func() T) bool {
+	if s.db == nil {
+		log.Ctx(ctx).Error().Msg("Storage healthcheck failed: db is nil")
+		return false
+	}
+	if s.db.IsClosed() {
+		log.Ctx(ctx).Error().Msg("Storage healthcheck failed: db is closed")
+		return false
+	}
+	if err := s.Hydrate(ctx, hydrationSample()); err != nil {
+		log.Ctx(ctx).Error().Err(err).Msg("Storage healthcheck failed: could not hydrate sample")
+		return false
+	}
+
+	return true
+}
+
 // NullStorage is a dummy object honoring the Storage interface, and can be used in unit tests
 // as a drop-in replacement in the dependencies if the test don't actually care about storage actions.
 type NullStorage[T object] struct{}
@@ -168,3 +188,7 @@ func (s NullStorage[T]) Hydrate(context.Context, T) error {
 func (s NullStorage[T]) Save(context.Context, T) error {
 	return nil
 }
+
+func (s NullStorage[T]) HealthCheck(context.Context, func() T) bool {
+	return true
+}