Add basic webserver skeleton with healthcheck

internal/healthcheck/healthcheck.go

@@ -0,0 +1,83 @@
+// Package healthcheck provides health check functionality.
+package healthcheck
+
+import (
+	"context"
+	"log/slog"
+	"time"
+
+	"go.uber.org/fx"
+	"sneak.berlin/go/pixa/internal/config"
+	"sneak.berlin/go/pixa/internal/database"
+	"sneak.berlin/go/pixa/internal/globals"
+	"sneak.berlin/go/pixa/internal/logger"
+)
+
+// HealthcheckParams defines dependencies for Healthcheck.
+type HealthcheckParams struct {
+	fx.In
+	Globals  *globals.Globals
+	Config   *config.Config
+	Logger   *logger.Logger
+	Database *database.Database
+}
+
+// Healthcheck provides health check information.
+type Healthcheck struct {
+	StartupTime time.Time
+	log         *slog.Logger
+	globals     *globals.Globals
+	config      *config.Config
+}
+
+// New creates a new Healthcheck instance.
+func New(lc fx.Lifecycle, params HealthcheckParams) (*Healthcheck, error) {
+	s := &Healthcheck{
+		log:     params.Logger.Get(),
+		globals: params.Globals,
+		config:  params.Config,
+	}
+
+	lc.Append(fx.Hook{
+		OnStart: func(ctx context.Context) error {
+			s.StartupTime = time.Now()
+
+			return nil
+		},
+		OnStop: func(ctx context.Context) error {
+			return nil
+		},
+	})
+
+	return s, nil
+}
+
+// HealthcheckResponse is the JSON response for health checks.
+type HealthcheckResponse struct {
+	Status        string `json:"status"`
+	Now           string `json:"now"`
+	UptimeSeconds int64  `json:"uptime_seconds"`
+	UptimeHuman   string `json:"uptime_human"`
+	Version       string `json:"version"`
+	Appname       string `json:"appname"`
+	Maintenance   bool   `json:"maintenance_mode"`
+}
+
+func (s *Healthcheck) uptime() time.Duration {
+	return time.Since(s.StartupTime)
+}
+
+// Healthcheck returns the current health status.
+func (s *Healthcheck) Healthcheck() *HealthcheckResponse {
+	resp := &HealthcheckResponse{
+		Status:        "ok",
+		Now:           time.Now().UTC().Format(time.RFC3339Nano),
+		UptimeSeconds: int64(s.uptime().Seconds()),
+		UptimeHuman:   s.uptime().String(),
+		Appname:       s.globals.Appname,
+		Version:       s.globals.Version,
+		Maintenance:   s.config.MaintenanceMode,
+	}
+
+	return resp
+}