chore: add Caddy gRPC service to retrieve Caddyfile config from machines

internal/machine/caddyconfig/service.go

@@ -0,0 +1,35 @@
+package caddyconfig
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+)
+
+// Service provides methods to interact with the Caddy configuration on the machine.
+type Service struct {
+	configDir string
+}
+
+// NewService creates a new Service instance with the specified Caddy configuration directory.
+func NewService(configDir string) *Service {
+	return &Service{configDir: configDir}
+}
+
+// Caddyfile retrieves the current Caddy configuration (Caddyfile) from the machine's config directory.
+func (s *Service) Caddyfile() (string, time.Time, error) {
+	path := filepath.Join(s.configDir, "Caddyfile")
+	content, err := os.ReadFile(path)
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("read Caddyfile from file '%s': %w", path, err)
+	}
+
+	// Get the file modification time.
+	fileInfo, err := os.Stat(path)
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("get Caddyfile file info '%s': %w", path, err)
+	}
+
+	return string(content), fileInfo.ModTime(), nil
+}