fix: fix validation for email configuration

internal/conf/notifications_email.go

@@ -1,22 +1,53 @@
 package conf
 
 import (
-	"errors"
+	"fmt"
 	"os"
 	"strings"
+
+	"github.com/go-playground/validator/v10"
 )
 
 type EmailConfig struct {
-	From             string   `yaml:"from" env:"EMAIL_FROM" validate:"required_with=SmtpHost,omitempty,required_without=FromFile"`
-	FromFile         string   `yaml:"from_file" env:"EMAIL_FROM_FILE" validate:"required_with=SmtpHost,omitempty,required_without=From"`
-	To               []string `yaml:"to"   env:"EMAIL_TO" envSeparator:";" validate:"required_with=SmtpHost,omitempty,required_without=ToFile"`
-	ToFile           string   `yaml:"to_file"   env:"EMAIL_TO" validate:"required_with=SmtpHost,omitempty,required_without=To"`
-	SmtpHost         string   `yaml:"host" env:"EMAIL_HOST" validate:"omitempty,required"`
-	SmtpPort         int      `yaml:"port" env:"EMAIL_PORT" validate:"omitempty,required"`
-	SmtpUsername     string   `yaml:"user" env:"EMAIL_USER" validate:"required_with=SmtpHost,omitempty,required_without=SmtpUsernameFile"`
-	SmtpUsernameFile string   `yaml:"user_file" env:"EMAIL_USER_FILE" validate:"required_with=SmtpHost,omitempty,required_without=smtpUsername"`
-	SmtpPassword     string   `yaml:"password" env:"EMAIL_PASSWORD" validate:"required_with=SmtpHost,omitempty,required_without=SmtpPasswordFile"`
-	SmtpPasswordFile string   `yaml:"password_file" env:"EMAIL_PASSWORD_FILE" validate:"required_with=SmtpHost,omitempty,required_without=SmtpPassword"`
+	From             string   `yaml:"from" env:"EMAIL_FROM" validate:"omitempty,email"`
+	FromFile         string   `yaml:"from_file" env:"EMAIL_FROM_FILE" validate:"omitempty,filepath"`
+	To               []string `yaml:"to" env:"EMAIL_TO" envSeparator:";" validate:"omitempty,dive,email"`
+	ToFile           string   `yaml:"to_file" env:"EMAIL_TO" validate:"omitempty,filepath"`
+	SmtpHost         string   `yaml:"host" env:"EMAIL_HOST" validate:"omitempty,hostname"`
+	SmtpPort         int      `yaml:"port" env:"EMAIL_PORT" validate:"omitempty,gte=25,lte=65535"`
+	SmtpUsername     string   `yaml:"user" env:"EMAIL_USER"`
+	SmtpUsernameFile string   `yaml:"user_file" env:"EMAIL_USER_FILE" validate:"omitempty,filepath"`
+	SmtpPassword     string   `yaml:"password" env:"EMAIL_PASSWORD"`
+	SmtpPasswordFile string   `yaml:"password_file" env:"EMAIL_PASSWORD_FILE" validate:"omitempty,filepath"`
+}
+
+func (e *EmailConfig) String() string {
+	var sb strings.Builder
+
+	sb.WriteString("EmailConfig {")
+	appendIfNotEmpty(&sb, "From", e.From)
+	appendIfNotEmpty(&sb, "FromFile", e.FromFile)
+	if len(e.To) > 0 {
+		sb.WriteString(fmt.Sprintf(" To: %v,", e.To))
+	}
+	appendIfNotEmpty(&sb, "ToFile", e.ToFile)
+	appendIfNotEmpty(&sb, "SmtpHost", e.SmtpHost)
+	if e.SmtpPort != 0 {
+		sb.WriteString(fmt.Sprintf(" SmtpPort: %d,", e.SmtpPort))
+	}
+	appendIfNotEmpty(&sb, "SmtpUsername", e.SmtpUsername)
+	appendIfNotEmpty(&sb, "SmtpUsernameFile", e.SmtpUsernameFile)
+	// Note: We deliberately exclude SmtpPassword from the output
+	appendIfNotEmpty(&sb, "SmtpPasswordFile", e.SmtpPasswordFile)
+	sb.WriteString(" }")
+
+	return sb.String()
+}
+
+func appendIfNotEmpty(sb *strings.Builder, fieldName, value string) {
+	if value != "" {
+		sb.WriteString(fmt.Sprintf(" %s: %s,", fieldName, value))
+	}
 }
 
 func (conf *EmailConfig) IsConfigured() bool {
@@ -75,20 +106,32 @@ func (conf *EmailConfig) GetPassword() (string, error) {
 }
 
 func (conf *EmailConfig) Validate() error {
-	if len(conf.From) == 0 {
-		return errors.New("'From' not defined")
+	return ValidateConfig(conf)
+}
+
+func EmailConfigStructLevelValidation(sl validator.StructLevel) {
+	config := sl.Current().Interface().(EmailConfig)
+
+	if config.SmtpPort == 0 && len(config.SmtpHost)+len(config.SmtpUsername)+len(config.SmtpUsernameFile)+len(config.SmtpPasswordFile)+len(config.SmtpPassword)+len(config.From)+len(config.FromFile)+len(config.To)+len(config.ToFile) == 0 {
+		return
 	}
-	if len(conf.To) == 0 {
-		return errors.New("'To' not defined")
+
+	if config.SmtpUsername == "" && config.SmtpUsernameFile == "" {
+		sl.ReportError(config.SmtpUsername, "SmtpUsername", "SmtpUsername", "usernameOrFileRequired", "")
+		sl.ReportError(config.SmtpUsernameFile, "SmtpUsernameFile", "SmtpUsernameFile", "usernameOrFileRequired", "")
 	}
-	if len(conf.SmtpHost) == 0 {
-		return errors.New("'SmtpHost' not defined")
+	if config.SmtpPassword == "" && config.SmtpPasswordFile == "" {
+		sl.ReportError(config.SmtpPassword, "SmtpPassword", "SmtpPassword", "passwordOrFileRequired", "")
+		sl.ReportError(config.SmtpPasswordFile, "SmtpPasswordFile", "SmtpPasswordFile", "passwordOrFileRequired", "")
 	}
-	if len(conf.SmtpUsername) == 0 {
-		return errors.New("'smtpUsername' not defined")
+
+	if config.From == "" && config.FromFile == "" {
+		sl.ReportError(config.From, "From", "From", "requiredWithoutFromFile", "")
+		sl.ReportError(config.FromFile, "FromFile", "FromFile", "requiredWithoutFrom", "")
 	}
-	if len(conf.SmtpPassword) == 0 {
-		return errors.New("'SmtpPassword' not defined")
+
+	if len(config.To) == 0 && config.ToFile == "" {
+		sl.ReportError(config.To, "To", "To", "requiredWithoutToFile", "")
+		sl.ReportError(config.ToFile, "ToFile", "ToFile", "requiredWithoutTo", "")
 	}
-	return nil
 }

internal/conf/notifications_email_test.go

@@ -0,0 +1,95 @@
+package conf
+
+import "testing"
+
+func TestEmailConfig_Validate(t *testing.T) {
+	type fields struct {
+		From             string
+		FromFile         string
+		To               []string
+		ToFile           string
+		SmtpHost         string
+		SmtpPort         int
+		SmtpUsername     string
+		SmtpUsernameFile string
+		SmtpPassword     string
+		SmtpPasswordFile string
+	}
+	tests := []struct {
+		name    string
+		fields  fields
+		wantErr bool
+	}{
+		{
+			name:    "valid config, nothing defined",
+			fields:  fields{},
+			wantErr: false,
+		},
+		{
+			name: "valid config, no files",
+			fields: fields{
+				From:         "dyndns@yourdomain.tld",
+				To:           []string{"you@yourdomain.tld"},
+				SmtpHost:     "localhost",
+				SmtpPort:     25,
+				SmtpUsername: "email",
+				SmtpPassword: "secret",
+			},
+			wantErr: false,
+		},
+		{
+			name: "valid config, use files",
+			fields: fields{
+				FromFile:         "from.txt",
+				ToFile:           "to.txt",
+				SmtpHost:         "localhost",
+				SmtpPort:         25,
+				SmtpUsernameFile: "user.txt",
+				SmtpPasswordFile: "secret.txt",
+			},
+			wantErr: false,
+		},
+		{
+			name: "valid config, mixed usage of files and actual values",
+			fields: fields{
+				FromFile:         "from.txt",
+				To:               []string{"mail@domain.tld"},
+				SmtpHost:         "localhost",
+				SmtpPort:         25,
+				SmtpUsername:     "user",
+				SmtpPasswordFile: "secret.txt",
+			},
+			wantErr: false,
+		},
+		{
+			name: "invalid config, missing from",
+			fields: fields{
+				ToFile:           "to.txt",
+				SmtpHost:         "localhost",
+				SmtpPort:         25,
+				SmtpUsernameFile: "user.txt",
+				SmtpPasswordFile: "secret.txt",
+			},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			conf := &EmailConfig{
+				From:             tt.fields.From,
+				FromFile:         tt.fields.FromFile,
+				To:               tt.fields.To,
+				ToFile:           tt.fields.ToFile,
+				SmtpHost:         tt.fields.SmtpHost,
+				SmtpPort:         tt.fields.SmtpPort,
+				SmtpUsername:     tt.fields.SmtpUsername,
+				SmtpUsernameFile: tt.fields.SmtpUsernameFile,
+				SmtpPassword:     tt.fields.SmtpPassword,
+				SmtpPasswordFile: tt.fields.SmtpPasswordFile,
+			}
+			if err := conf.Validate(); (err != nil) != tt.wantErr {
+				t.Errorf("Validate() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}

internal/conf/pretty_printer.go

@@ -3,12 +3,13 @@ package conf
 import (
 	"fmt"
 	"reflect"
+	"slices"
 	"strings"
 
 	"github.com/rs/zerolog/log"
 )
 
-var SensitiveFields = []string{"KeyPair"}
+var SensitiveFields = []string{"KeyPair", "SmtpPassword"}
 
 func PrintFields(data any, ignoredKeys ...string) {
 	v := reflect.ValueOf(data)
@@ -24,7 +25,7 @@ func PrintFields(data any, ignoredKeys ...string) {
 			continue
 		}
 
-		if sliceContains(ignoredKeys, field.Name) {
+		if slices.Contains(ignoredKeys, field.Name) {
 			log.Info().Msgf("%s=%s", field.Name, "*** (redacted)")
 		} else {
 			log.Info().Msgf("%s=%s", field.Name, fieldValueToString(field.Name, value))
@@ -45,9 +46,25 @@ func sliceContains(slice []string, val string) bool {
 
 func fieldValueToString(nam string, value reflect.Value) string {
 	if value.CanInterface() {
+		if value.Kind() == reflect.Ptr {
+			// Handle the case where value is a pointer
+			if value.IsNil() {
+				return "<nil>"
+			}
+			value = value.Elem()
+		}
+
 		if stringer, ok := value.Interface().(fmt.Stringer); ok {
 			return stringer.String()
 		}
+
+		// Check if the address of the struct implements fmt.Stringer
+		if value.Kind() == reflect.Struct {
+			ptrValue := value.Addr()
+			if stringer, ok := ptrValue.Interface().(fmt.Stringer); ok {
+				return stringer.String()
+			}
+		}
 	}
 	return fmt.Sprintf("%v", value.Interface())
 }

internal/conf/validation.go

@@ -28,6 +28,8 @@ func ValidateConfig[T any](c T) error {
 		if err := validate.RegisterValidation("broker", validateBrokers); err != nil {
 			log.Fatal().Err(err).Msg("could not build custom validation 'validateBrokers'")
 		}
+
+		validate.RegisterStructValidation(EmailConfigStructLevelValidation, EmailConfig{})
 	})
 
 	return validate.Struct(c)