override config flags

1 files changed, 114 insertions, 0 deletions

diff --git a/cmd/util/config.go b/cmd/util/config.go
new file mode 100644
index 00000000..a829f44c
--- /dev/null
+++ b/cmd/util/config.go
@@ -0,0 +1,114 @@
+package util
+
+import (
+	"fmt"
+	"github.com/spf13/viper"
+	"github.com/spiral/roadrunner/service"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// configWrapper provides interface bridge between v configs and service.Config.
+type configWrapper struct {
+	v *viper.Viper
+}
+
+// Get nested config section (sub-map), returns nil if section not found.
+func (w *configWrapper) Get(key string) service.Config {
+	sub := w.v.Sub(key)
+	if sub == nil {
+		return nil
+	}
+
+	return &configWrapper{sub}
+}
+
+// Unmarshal unmarshal config data into given struct.
+func (w *configWrapper) Unmarshal(out interface{}) error {
+	return w.v.Unmarshal(out)
+}
+
+// LoadConfig config and merge it's values with set of flags.
+func LoadConfig(cfgFile string, path []string, name string, flags []string) (*configWrapper, error) {
+	cfg := viper.New()
+
+	if cfgFile != "" {
+		if absPath, err := filepath.Abs(cfgFile); err == nil {
+			cfgFile = absPath
+
+			// force working absPath related to config file
+			if err := os.Chdir(filepath.Dir(absPath)); err != nil {
+				return nil, err
+			}
+		}
+
+		// Use cfg file from the flag.
+		cfg.SetConfigFile(cfgFile)
+
+		if dir, err := filepath.Abs(cfgFile); err == nil {
+			// force working absPath related to config file
+			if err := os.Chdir(filepath.Dir(dir)); err != nil {
+				return nil, err
+			}
+		}
+	} else {
+		// automatic location
+		for _, p := range path {
+			cfg.AddConfigPath(p)
+		}
+
+		cfg.SetConfigName(name)
+	}
+
+	// read in environment variables that match
+	cfg.AutomaticEnv()
+
+	// If a cfg file is found, read it in.
+	if err := cfg.ReadInConfig(); err != nil {
+		return nil, err
+	}
+
+	if len(flags) != 0 {
+		for _, f := range flags {
+			k, v, err := parseFlag(f)
+			if err != nil {
+				return nil, err
+			}
+
+			cfg.Set(k, v)
+		}
+
+		merged := viper.New()
+
+		// we have to copy all the merged values into new config in order normalize it (viper bug?)
+		if err := merged.MergeConfigMap(cfg.AllSettings()); err != nil {
+			return nil, err
+		}
+
+		return &configWrapper{merged}, nil
+	}
+
+	return &configWrapper{cfg}, nil
+}
+
+func parseFlag(flag string) (string, string, error) {
+	if !strings.Contains(flag, "=") {
+		return "", "", fmt.Errorf("invalid flag `%s`", flag)
+	}
+
+	parts := strings.SplitN(strings.TrimLeft(flag, " \"'`"), "=", 2)
+
+	return strings.Trim(parts[0], " \n\t"), parseValue(strings.Trim(parts[1], " \n\t")), nil
+}
+
+func parseValue(value string) string {
+	escape := []rune(value)[0]
+
+	if escape == '"' || escape == '\'' || escape == '`' {
+		value = strings.Trim(value, string(escape))
+		value = strings.Replace(value, fmt.Sprintf("\\%s", string(escape)), string(escape), -1)
+	}
+
+	return value
+}