snapshot of https://github.com/centrifugal/centrifugo.git (master, 2026-09-16; blobs > 131072B omitted)

internal/configtypes/stringmap.go

@@ -0,0 +1,117 @@
+package configtypes
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"reflect"
+	"regexp"
+
+	"github.com/go-viper/mapstructure/v2"
+)
+
+type MapStringString map[string]string
+
+var customEnvVarRegex = regexp.MustCompile(`\$\{(CENTRIFUGO_VAR_[^}]+)}`)
+
+func expandEnvVars(m map[string]string) error {
+	for key, val := range m {
+		// First check if all CENTRIFUGO_VAR_ environment variables exist.
+		matches := customEnvVarRegex.FindAllStringSubmatch(val, -1)
+		for _, match := range matches {
+			if len(match) > 1 {
+				envVar := match[1]
+
+				// Check if the environment variable exists.
+				if _, exists := os.LookupEnv(envVar); !exists {
+					return fmt.Errorf("environment variable %q not found", envVar)
+				}
+			}
+		}
+
+		// If all variables exist, do the replacement.
+		m[key] = customEnvVarRegex.ReplaceAllStringFunc(val, func(match string) string {
+			submatches := customEnvVarRegex.FindStringSubmatch(match)
+			if len(submatches) > 1 {
+				return os.Getenv(submatches[1])
+			}
+			return match // Fallback, shouldn't happen.
+		})
+	}
+	return nil
+}
+
+func (s *MapStringString) Decode(value string) error {
+	var m map[string]string
+	err := json.Unmarshal([]byte(value), &m)
+	if err != nil {
+		return err
+	}
+
+	err = expandEnvVars(m)
+	if err != nil {
+		return err
+	}
+
+	*s = m
+	return nil
+}
+
+func StringToMapStringStringHookFunc() mapstructure.DecodeHookFunc {
+	return func(f reflect.Type, t reflect.Type, data any) (any, error) {
+		if t != reflect.TypeOf(MapStringString{}) {
+			return data, nil
+		}
+
+		switch v := data.(type) {
+
+		// Old behavior: map[string]any – it's case-insensitive, and does not support dot (key delimiter in Viper) in the key.
+		case map[string]any:
+			m := make(map[string]string)
+			for key, value := range v {
+				strValue, ok := value.(string)
+				if !ok {
+					return nil, fmt.Errorf("expected string value for key %q, got %T", key, value)
+				}
+				m[key] = strValue
+			}
+			if err := expandEnvVars(m); err != nil {
+				return nil, err
+			}
+			return MapStringString(m), nil
+
+		// Slice of key/value objects is the recommended way to define maps now.
+		case []any:
+			m := make(map[string]string)
+			for i, item := range v {
+				kvMap, ok := item.(map[string]any)
+				if !ok {
+					return nil, fmt.Errorf("expected map for element %d, got %T", i, item)
+				}
+
+				keyI, ok := kvMap["key"].(string)
+				if !ok {
+					return nil, fmt.Errorf("missing or invalid key in element %d", i)
+				}
+
+				if _, exists := m[keyI]; exists {
+					return nil, fmt.Errorf("duplicate key %q at element %d", keyI, i)
+				}
+
+				valI, ok := kvMap["value"].(string)
+				if !ok {
+					return nil, fmt.Errorf("missing or invalid value in element %d", i)
+				}
+
+				m[keyI] = valI
+			}
+			if err := expandEnvVars(m); err != nil {
+				return nil, err
+			}
+			return MapStringString(m), nil
+
+		default:
+			return nil, fmt.Errorf("unsupported type %T for MapStringString", data)
+		}
+	}
+}