fix(caddyconfig): custom global Caddy config is preserved on regeneration,warn about last load error in 'uc caddy config' (fixes #412)

internal/machine/caddyconfig/service.go

@@ -4,12 +4,15 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sync"
 	"time"
 )
 
 // Service provides methods to interact with the Caddy configuration on the machine.
 type Service struct {
-	configDir string
+	configDir               string
+	mu                      sync.RWMutex
+	lastReconciliationError error
 }
 
 // NewService creates a new Service instance with the specified Caddy configuration directory.
@@ -17,7 +20,8 @@ func NewService(configDir string) *Service {
 	return &Service{configDir: configDir}
 }
 
-// Caddyfile retrieves the current Caddy configuration (Caddyfile) from the machine's config directory.
+// Caddyfile retrieves the saved Caddyfile from the machine's config directory. The saved file may differ from the
+// running configuration if Caddy accepted a load but the subsequent write failed.
 func (s *Service) Caddyfile() (string, time.Time, error) {
 	path := filepath.Join(s.configDir, "Caddyfile")
 	content, err := os.ReadFile(path)
@@ -33,3 +37,17 @@ func (s *Service) Caddyfile() (string, time.Time, error) {
 
 	return string(content), fileInfo.ModTime(), nil
 }
+
+// LastReconciliationError reports the most recent unsuccessful controller attempt, if any. A successful attempt
+// clears it. An empty value does not prove that Caddy has loaded the saved Caddyfile.
+func (s *Service) LastReconciliationError() error {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	return s.lastReconciliationError
+}
+
+func (s *Service) setReconciliationResult(err error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.lastReconciliationError = err
+}