fix: Workaround until fix of spf13/viper#338 (fixes #218)

cmd/gate/root.go

@@ -1,19 +1,24 @@
 package gate
 
 import (
+	"bytes"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"math"
 	"os"
+	"path"
 	"strings"
 
 	"github.com/go-logr/logr"
 	"github.com/go-logr/zapr"
 	"github.com/spf13/viper"
 	"github.com/urfave/cli/v2"
 	"go.minekube.com/gate/pkg/gate"
+	"go.minekube.com/gate/pkg/gate/config"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
+	"gopkg.in/yaml.v3"
 )
 
 // Execute runs App() and calls os.Exit when finished.
@@ -115,7 +120,8 @@ func initViper(c *cli.Context, configFile string) (*viper.Viper, error) {
 	v.AutomaticEnv() // read in environment variables that match
 	v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
 	// Read in config.
-	if err := v.ReadInConfig(); err != nil {
+	cfgCopy := func() config.Config { return config.DefaultConfig }()
+	if err := FixedReadInConfig(v, configFile, &cfgCopy); err != nil {
 		// A config file is only required to exist when explicit config flag was specified.
 		if !(errors.As(err, &viper.ConfigFileNotFoundError{}) || os.IsNotExist(err)) || c.IsSet("config") {
 			return nil, fmt.Errorf("error reading config file %q: %w", v.ConfigFileUsed(), err)
@@ -124,6 +130,40 @@ func initViper(c *cli.Context, configFile string) (*viper.Viper, error) {
 	return v, nil
 }
 
+// FixedReadInConfig is a workaround for https://github.com/minekube/gate/issues/218#issuecomment-1632800775
+func FixedReadInConfig[T any](v *viper.Viper, configFile string, defaultConfig *T) error {
+	if configFile == "" || defaultConfig == nil {
+		return v.ReadInConfig()
+	}
+
+	var (
+		unmarshal func([]byte, any) error
+		marshal   func(any) ([]byte, error)
+	)
+	switch path.Ext(configFile) {
+	case ".yaml", ".yml":
+		unmarshal = yaml.Unmarshal
+		marshal = yaml.Marshal
+	case ".json":
+		unmarshal = json.Unmarshal
+		marshal = json.Marshal
+	default:
+		return fmt.Errorf("unsupported config file format %q", configFile)
+	}
+	b, err := os.ReadFile(configFile)
+	if err != nil {
+		return fmt.Errorf("error reading config file %q: %w", configFile, err)
+	}
+	if err = unmarshal(b, defaultConfig); err != nil {
+		return fmt.Errorf("error unmarshaling config file %q to %T: %w", configFile, defaultConfig, err)
+	}
+	if b, err = marshal(defaultConfig); err != nil {
+		return fmt.Errorf("error marshaling config file %q: %w", configFile, err)
+	}
+
+	return v.ReadConfig(bytes.NewReader(b))
+}
+
 // newLogger returns a new zap logger with a modified production
 // or development default config to ensure human readability.
 func newLogger(debug bool, v int) (l logr.Logger, err error) {

pkg/util/favicon/favicon.go

@@ -9,6 +9,7 @@ import (
 	_ "image/jpeg"
 	"image/png"
 	"os"
+	"path"
 	"strings"
 
 	"github.com/nfnt/resize"
@@ -95,6 +96,9 @@ func Parse(s string) (Favicon, error) {
 		}
 		return f, nil
 	}
+	if path.Ext(s) != "" {
+		return "", fmt.Errorf("favicon: file %s not found", s)
+	}
 	return "", fmt.Errorf("favicon: invalid format: %s", s)
 }