WIP: EOL

internal/server/server.go

@@ -0,0 +1,145 @@
+package server
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"sync"
+	"syscall"
+	"time"
+
+	fiberzap "github.com/gofiber/contrib/fiberzap/v2"
+	"github.com/gofiber/contrib/swagger"
+	"github.com/gofiber/fiber/v2"
+	middleware "github.com/oapi-codegen/fiber-middleware"
+	"gitlab.mareshq.com/hq/backoffice/backoffice-api/internal/api"
+	"go.uber.org/zap"
+)
+
+type Server struct {
+	ready ready
+}
+
+func NewServer() *Server {
+	return &Server{}
+}
+
+func (s *Server) Run() {
+	shutdownCtx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	logger, err := zap.NewProduction()
+	if err != nil {
+		logger.Fatal("failed to initialize logger", zap.Error(err))
+	}
+	defer logger.Sync()
+	sugaredLogger := logger.Sugar()
+
+	fiberConfig := fiber.Config{
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 5 * time.Second,
+		IdleTimeout:  5 * time.Second,
+
+		DisableStartupMessage: true,
+	}
+
+	app := fiber.New(fiberConfig)
+
+	app.Get("/", func(c *fiber.Ctx) error {
+		return c.SendStatus(fiber.StatusNotFound)
+	})
+
+	app.Get("/livez", func(c *fiber.Ctx) error {
+		return c.SendStatus(fiber.StatusOK)
+	})
+
+	app.Get("/readyz", func(c *fiber.Ctx) error {
+		if s.ready.isReady() {
+			return c.SendStatus(fiber.StatusOK)
+		}
+
+		return c.SendStatus(fiber.StatusServiceUnavailable)
+	})
+
+	// TODO: add /metrics endpoint
+
+	app.Use(fiberzap.New(fiberzap.Config{
+		Logger: logger,
+	}))
+
+	swaggerConfig := swagger.Config{
+		BasePath: "/",
+		FilePath: "./api/v1/openapi.yaml",
+		Path:     "/swagger",
+		Title:    "Swagger API Docs",
+	}
+
+	app.Use(swagger.New(swaggerConfig))
+
+	app = registerAPIHandlers(app, sugaredLogger)
+
+	<-shutdownCtx.Done()
+	stop()
+	s.ready.notReady()
+
+	// wait till Pod is signaling not ready (no new requests)
+	time.Sleep(5 * time.Second)
+
+	shutdownBegan := time.Now()
+
+	sugaredLogger.Info("Shutdown signal recieved. Shutting down gracefully...")
+
+	// * Gracefully shut down fiber server
+	// * If does not shutdown within `gracefulShutdownPeriod`, force shutdown
+	// ! Does not close keep-alive connections
+	// ! fiber.Config{ReadTimeout} must be set and non-zero and greater than the `gracefulShutdownPeriod`
+	// TODO: make shutdown timeout configurable
+	err = app.ShutdownWithTimeout(time.Second * 10)
+	if err != nil {
+		sugaredLogger.Errorw("Error during shutdown", "error", err)
+	}
+
+	sugaredLogger.Infof("Shutdown completed in %v", time.Since(shutdownBegan))
+}
+
+func registerAPIHandlers(fiberApp *fiber.App, logger *zap.SugaredLogger) *fiber.App {
+	swagger, err := api.GetSwagger()
+	if err != nil {
+		logger.Fatalf("Error getting swagger: %v", err)
+	}
+
+	// TODO: validate this. Copied from example
+	// See: https://github.com/deepmap/oapi-codegen/blob/master/examples/petstore-expanded/fiber/petstore.go#L41
+	// Clear out the servers array in the swagger spec, that skips validating
+	// that server names match. We don't know how this thing will be run.
+	swagger.Servers = nil
+
+	fiberApp.Use(middleware.OapiRequestValidator(swagger))
+
+	api.RegisterHandlers(fiberApp)
+
+	return fiberApp
+}
+
+type ready struct {
+	ready bool
+	lock  sync.Mutex
+}
+
+func (r *ready) setReady() {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	r.ready = true
+}
+
+func (r *ready) isReady() bool {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	return r.ready
+}
+
+func (r *ready) notReady() {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	r.ready = false
+}