feat(parser): support multiple -C config files, merged left-to-right

Allow passing -C multiple times to load and merge several configuration
files in order. Slice fields are appended; scalar fields (TLS, Log, API,
Metrics, Profiling) are overridden by later files — the same semantics as
the existing mergeConfig() used for CLI+config merging.

- Change Args.CfgFile string to Args.CfgFiles []string
- Extract readConfig() helper from Parse() for single-source loading
- Loop over CfgFiles in Parse(), merging each into the accumulator
- Add Quotas to mergeConfig (was missing from the slice list)
- Add TestParse_MultiFile integration test for two-file merge

Closes go-gost/gost#150

config/parsing/parser/parse_test.go

@@ -1,6 +1,8 @@
 package parser
 
 import (
+	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/go-gost/x/config"
@@ -47,6 +49,7 @@ func TestMergeConfig_AppendsAllSlices(t *testing.T) {
 		SDs:        []*config.SDConfig{{Name: "sd1"}},
 		Recorders:  []*config.RecorderConfig{{Name: "rec1"}},
 		Limiters:   []*config.LimiterConfig{{Name: "l1"}},
+		Quotas:     []*config.QuotaConfig{{Name: "q1"}},
 		CLimiters:  []*config.LimiterConfig{{Name: "cl1"}},
 		RLimiters:  []*config.LimiterConfig{{Name: "rl1"}},
 		Loggers:    []*config.LoggerConfig{{Name: "log1"}},
@@ -66,6 +69,7 @@ func TestMergeConfig_AppendsAllSlices(t *testing.T) {
 		SDs:        []*config.SDConfig{{Name: "sd2"}},
 		Recorders:  []*config.RecorderConfig{{Name: "rec2"}},
 		Limiters:   []*config.LimiterConfig{{Name: "l2"}},
+		Quotas:     []*config.QuotaConfig{{Name: "q2"}},
 		CLimiters:  []*config.LimiterConfig{{Name: "cl2"}},
 		RLimiters:  []*config.LimiterConfig{{Name: "rl2"}},
 		Loggers:    []*config.LoggerConfig{{Name: "log2"}},
@@ -111,6 +115,9 @@ func TestMergeConfig_AppendsAllSlices(t *testing.T) {
 	if len(got.Limiters) != 2 {
 		t.Fatal("limiters not properly appended")
 	}
+	if len(got.Quotas) != 2 {
+		t.Fatal("quotas not properly appended")
+	}
 	if len(got.CLimiters) != 2 {
 		t.Fatal("climiters not properly appended")
 	}
@@ -194,7 +201,7 @@ func TestMergeConfig_ScalarKeepsCfg1WhenCfg2Nil(t *testing.T) {
 
 func TestInit(t *testing.T) {
 	Init(Args{
-		CfgFile:     "test.yml",
+		CfgFiles:    []string{"test.yml"},
 		Services:    []string{"s1"},
 		Nodes:       []string{"n1"},
 		Debug:       true,
@@ -203,8 +210,8 @@ func TestInit(t *testing.T) {
 		MetricsAddr: ":9090",
 	})
 
-	if defaultParser.args.CfgFile != "test.yml" {
+	if len(defaultParser.args.CfgFiles) != 1 || defaultParser.args.CfgFiles[0] != "test.yml" {
-		t.Fatalf("CfgFile not set: got %q", defaultParser.args.CfgFile)
+		t.Fatalf("CfgFiles not set: got %v", defaultParser.args.CfgFiles)
 	}
 	if len(defaultParser.args.Services) != 1 || defaultParser.args.Services[0] != "s1" {
 		t.Fatal("Services not set")
@@ -225,3 +232,56 @@ func TestInit(t *testing.T) {
 		t.Fatal("MetricsAddr not set")
 	}
 }
+
+func TestParse_MultiFile(t *testing.T) {
+	// Create two temporary config files.
+	cfg1 := &config.Config{
+		Services: []*config.ServiceConfig{{Name: "s1", Addr: ":8080"}},
+	}
+	cfg2 := &config.Config{
+		Services: []*config.ServiceConfig{{Name: "s2", Addr: ":8081"}},
+		Log:      &config.LogConfig{Level: "debug"},
+		Quotas:   []*config.QuotaConfig{{Name: "q1"}},
+	}
+
+	tmpDir := t.TempDir()
+	file1 := filepath.Join(tmpDir, "cfg1.yml")
+	file2 := filepath.Join(tmpDir, "cfg2.yml")
+
+	for _, entry := range []struct {
+		path string
+		cfg  *config.Config
+	}{
+		{file1, cfg1},
+		{file2, cfg2},
+	} {
+		f, err := os.Create(entry.path)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := entry.cfg.Write(f, "yaml"); err != nil {
+			f.Close()
+			t.Fatal(err)
+		}
+		f.Close()
+	}
+
+	Init(Args{
+		CfgFiles: []string{file1, file2},
+	})
+
+	got, err := Parse()
+	if err != nil {
+		t.Fatalf("Parse(): %v", err)
+	}
+
+	if len(got.Services) != 2 {
+		t.Fatalf("expected 2 services, got %d", len(got.Services))
+	}
+	if got.Log == nil || got.Log.Level != "debug" {
+		t.Fatal("Log.Level not set from cfg2")
+	}
+	if len(got.Quotas) != 1 || got.Quotas[0].Name != "q1" {
+		t.Fatal("Quotas not merged from cfg2")
+	}
+}

config/parsing/parser/parser.go

@@ -35,9 +35,9 @@ func Parse() (*config.Config, error) {
 // Args holds the raw CLI flags and positional arguments that Init will merge
 // into the final configuration.
 type Args struct {
-	// CfgFile is the path to a YAML or JSON config file, "-" for stdin, or
+	// CfgFiles is the list of YAML or JSON config file paths, "-" for stdin, or
-	// an inline JSON string.
+	// an inline JSON string. Multiple files are merged left-to-right.
-	CfgFile string
+	CfgFiles []string
 
 	// Services is the list of service definitions from -L flags.
 	Services []string
@@ -65,31 +65,16 @@ type parser struct {
 func (p *parser) Parse() (*config.Config, error) {
 	cfg := &config.Config{}
 
-	if cfgFile := strings.TrimSpace(p.args.CfgFile); cfgFile != "" {
+	for _, cfgFile := range p.args.CfgFiles {
-		if cfgFile == "-" { // stdin
+		cfgFile = strings.TrimSpace(cfgFile)
-			br := bufio.NewReader(os.Stdin)
+		if cfgFile == "" {
-			b, err := br.Peek(1)
+			continue
+		}
+		fcfg, err := readConfig(cfgFile)
 		if err != nil {
 			return nil, err
 		}
-			if b[0] == '{' {
+		cfg = mergeConfig(cfg, fcfg)
-				if err := cfg.Read(br, "json"); err != nil {
-					return nil, err
-				}
-			} else {
-				if err := cfg.Read(br, "yaml"); err != nil {
-					return nil, err
-				}
-			}
-		} else if strings.HasPrefix(cfgFile, "{") && strings.HasSuffix(cfgFile, "}") { // inline
-			if err := json.Unmarshal([]byte(cfgFile), cfg); err != nil {
-				return nil, err
-			}
-		} else {
-			if err := cfg.ReadFile(cfgFile); err != nil { // file
-				return nil, err
-			}
-		}
 	}
 
 	cmdCfg, err := cmd.BuildConfigFromCmd(p.args.Services, p.args.Nodes)
@@ -193,6 +178,39 @@ func (p *parser) Parse() (*config.Config, error) {
 	return cfg, nil
 }
 
+// readConfig reads a single configuration source, which may be "-" (stdin),
+// an inline JSON string starting with "{", or a file path.
+func readConfig(cfgFile string) (*config.Config, error) {
+	cfg := &config.Config{}
+
+	if cfgFile == "-" { // stdin
+		br := bufio.NewReader(os.Stdin)
+		b, err := br.Peek(1)
+		if err != nil {
+			return nil, err
+		}
+		if b[0] == '{' {
+			if err := cfg.Read(br, "json"); err != nil {
+				return nil, err
+			}
+		} else {
+			if err := cfg.Read(br, "yaml"); err != nil {
+				return nil, err
+			}
+		}
+	} else if strings.HasPrefix(cfgFile, "{") && strings.HasSuffix(cfgFile, "}") { // inline
+		if err := json.Unmarshal([]byte(cfgFile), cfg); err != nil {
+			return nil, err
+		}
+	} else {
+		if err := cfg.ReadFile(cfgFile); err != nil { // file
+			return nil, err
+		}
+	}
+
+	return cfg, nil
+}
+
 func mergeConfig(cfg1, cfg2 *config.Config) *config.Config {
 	if cfg1 == nil {
 		return cfg2
@@ -214,6 +232,7 @@ func mergeConfig(cfg1, cfg2 *config.Config) *config.Config {
 		SDs:        append(cfg1.SDs, cfg2.SDs...),
 		Recorders:  append(cfg1.Recorders, cfg2.Recorders...),
 		Limiters:   append(cfg1.Limiters, cfg2.Limiters...),
+		Quotas:     append(cfg1.Quotas, cfg2.Quotas...),
 		CLimiters:  append(cfg1.CLimiters, cfg2.CLimiters...),
 		RLimiters:  append(cfg1.RLimiters, cfg2.RLimiters...),
 		Loggers:    append(cfg1.Loggers, cfg2.Loggers...),