feat: add health endpoint

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [v0.1.24]
+### Added
+- Health check endpoint
+
 ## [v0.1.23]
 ### Fixed
 - Update crypto to v0.31.0 package because of CVE-2024-45337

di/wire.go

@@ -17,6 +17,7 @@ import (
 	"go.openfort.xyz/shield/internal/adapters/repositories/sql/providerrepo"
 	"go.openfort.xyz/shield/internal/adapters/repositories/sql/sharerepo"
 	"go.openfort.xyz/shield/internal/adapters/repositories/sql/userrepo"
+	"go.openfort.xyz/shield/internal/applications/healthzapp"
 	"go.openfort.xyz/shield/internal/applications/projectapp"
 	"go.openfort.xyz/shield/internal/applications/shamirjob"
 	"go.openfort.xyz/shield/internal/applications/shareapp"
@@ -196,12 +197,22 @@ func ProvideIdentityFactory() (f factories.IdentityFactory, err error) {
 	return
 }
 
+func ProvideHealthzApplication() (a *healthzapp.Application, err error) {
+	wire.Build(
+		ProvideSQL,
+		healthzapp.New,
+	)
+
+	return
+}
+
 func ProvideRESTServer() (s *rest.Server, err error) {
 	wire.Build(
 		rest.New,
 		rest.GetConfigFromEnv,
 		ProvideShareApplication,
 		ProvideProjectApplication,
+		ProvideHealthzApplication,
 		ProvideUserService,
 		ProvideAuthenticationFactory,
 		ProvideIdentityFactory,

internal/adapters/handlers/rest/healthzhdl/handler.go

@@ -0,0 +1,60 @@
+package healthzhdl
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"time"
+
+	"go.openfort.xyz/shield/internal/applications/healthzapp"
+	domainErrors "go.openfort.xyz/shield/internal/core/domain/errors"
+)
+
+type Handler struct {
+	app *healthzapp.Application
+}
+
+func New(app *healthzapp.Application) *Handler {
+	return &Handler{
+		app: app,
+	}
+}
+
+type Status struct {
+	Status string  `json:"status"`
+	At     string  `json:"at"`
+	Checks []Check `json:"checks"`
+}
+
+type Check struct {
+	Name   string `json:"name"`
+	Status string `json:"status"`
+}
+
+func (h *Handler) Healthz(w http.ResponseWriter, r *http.Request) {
+	status := Status{
+		Status: "healthy",
+		At:     time.Now().UTC().Format(time.RFC3339),
+		Checks: []Check{},
+	}
+
+	err := h.app.Healthz(r.Context())
+	if err != nil {
+		status.Status = "unhealthy"
+		if errors.Is(err, domainErrors.ErrDatabaseUnavailable) {
+			status.Checks = append(status.Checks, Check{
+				Name:   "database",
+				Status: "unhealthy",
+			})
+		}
+	} else {
+		status.Checks = append(status.Checks, Check{
+			Name:   "database",
+			Status: "healthy",
+		})
+	}
+
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	_ = json.NewEncoder(w).Encode(status)
+}

internal/adapters/handlers/rest/server.go

@@ -7,6 +7,9 @@ import (
 	"net/http"
 	"strings"
 
+	"go.openfort.xyz/shield/internal/adapters/handlers/rest/healthzhdl"
+	"go.openfort.xyz/shield/internal/applications/healthzapp"
+
 	"go.openfort.xyz/shield/internal/core/ports/factories"
 	"go.openfort.xyz/shield/internal/core/ports/services"
 
@@ -27,6 +30,7 @@ import (
 type Server struct {
 	projectApp            *projectapp.ProjectApplication
 	shareApp              *shareapp.ShareApplication
+	healthzApp            *healthzapp.Application
 	server                *http.Server
 	logger                *slog.Logger
 	config                *Config
@@ -36,10 +40,11 @@ type Server struct {
 }
 
 // New creates a new REST server
-func New(cfg *Config, projectApp *projectapp.ProjectApplication, shareApp *shareapp.ShareApplication, authenticationFactory factories.AuthenticationFactory, identityFactory factories.IdentityFactory, userService services.UserService) *Server {
+func New(cfg *Config, projectApp *projectapp.ProjectApplication, shareApp *shareapp.ShareApplication, authenticationFactory factories.AuthenticationFactory, identityFactory factories.IdentityFactory, userService services.UserService, healthzApp *healthzapp.Application) *Server {
 	return &Server{
 		projectApp:            projectApp,
 		shareApp:              shareApp,
+		healthzApp:            healthzApp,
 		server:                new(http.Server),
 		logger:                logger.New("rest_server"),
 		config:                cfg,
@@ -51,6 +56,7 @@ func New(cfg *Config, projectApp *projectapp.ProjectApplication, shareApp *share
 
 // Start starts the REST server
 func (s *Server) Start(ctx context.Context) error {
+	healthzHdl := healthzhdl.New(s.healthzApp)
 	projectHdl := projecthdl.New(s.projectApp)
 	shareHdl := sharehdl.New(s.shareApp)
 	authMdw := authmdw.New(s.authenticationFactory, s.identityFactory, s.userService)
@@ -60,6 +66,7 @@ func (s *Server) Start(ctx context.Context) error {
 	r.Use(rateLimiterMdw.RateLimitMiddleware)
 	r.Use(requestmdw.RequestIDMiddleware)
 	r.Use(responsemdw.ResponseMiddleware)
+	r.HandleFunc("/healthz", healthzHdl.Healthz).Methods(http.MethodGet)
 	r.HandleFunc("/register", projectHdl.CreateProject).Methods(http.MethodPost)
 	p := r.PathPrefix("/project").Subrouter()
 	p.Use(authMdw.AuthenticateAPISecret)

internal/applications/healthzapp/app.go

@@ -0,0 +1,37 @@
+package healthzapp
+
+import (
+	"context"
+	"log/slog"
+
+	"go.openfort.xyz/shield/internal/adapters/repositories/sql"
+	"go.openfort.xyz/shield/internal/core/domain/errors"
+	"go.openfort.xyz/shield/pkg/logger"
+)
+
+type Application struct {
+	db     *sql.Client
+	logger *slog.Logger
+}
+
+func New(db *sql.Client) *Application {
+	return &Application{
+		db:     db,
+		logger: logger.New("health_application"),
+	}
+}
+
+func (a *Application) Healthz(ctx context.Context) error {
+	db, err := a.db.DB.DB()
+	if err != nil {
+		a.logger.ErrorContext(ctx, "failed to get database connection", logger.Error(err))
+		return errors.ErrDatabaseUnavailable
+	}
+
+	if err = db.PingContext(ctx); err != nil {
+		a.logger.ErrorContext(ctx, "failed to ping database", logger.Error(err))
+		return errors.ErrDatabaseUnavailable
+	}
+
+	return nil
+}

internal/core/domain/errors/infra.go

@@ -0,0 +1,7 @@
+package errors
+
+import "errors"
+
+var (
+	ErrDatabaseUnavailable = errors.New("database unavailable")
+)