#11 Added directive expander

config.sample.yaml

@@ -0,0 +1,8 @@
+telemetry:
+  logging:
+    level: INFO  # DEBUG, INFO, WARNING, ERROR, FATAL
+    encoding: json # console, json
+
+#api:
+#  http:
+#    ...

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/cloudwego/hertz v0.7.3
 	github.com/go-playground/validator/v10 v10.16.0
 	github.com/hertz-contrib/logger/zap v1.1.0
+	github.com/mitchellh/mapstructure v1.5.0
 	github.com/spf13/cobra v1.8.0
 	go.uber.org/goleak v1.3.0
 	go.uber.org/multierr v1.11.0

go.sum

@@ -57,6 +57,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/leodido/go-urn v1.2.4 h1:XlAE/cm/ms7TE/VMVoduSpNBoyc2dOxHs5MZSwAN63Q=
 github.com/leodido/go-urn v1.2.4/go.mod h1:7ZrI8mTSeBSHl/UaRyKQW1qZeMgak41ANeCNaVckg+4=
+github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
+github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/nyaruka/phonenumbers v1.0.55 h1:bj0nTO88Y68KeUQ/n3Lo2KgK7lM1hF7L9NFuwcCl3yg=
 github.com/nyaruka/phonenumbers v1.0.55/go.mod h1:sDaTZ/KPX5f8qyV9qN+hIm+4ZBARJrupC6LuhshJq1U=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=

pkg/api/config.go

@@ -4,5 +4,5 @@ import "glide/pkg/api/http"
 
 // Config defines configuration for all API types we support (e.g. HTTP, gRPC)
 type Config struct {
-	Http http.ServerConfig `json:"http" yaml:"http"`
+	Http http.ServerConfig `mapstructure:"http"`
 }

pkg/cmd/cli.go

@@ -16,7 +16,7 @@ func NewCLI() *cobra.Command {
 		Use:     "glide",
 		Short:   "🐦Glide is an open source lightweight high-performant model gateway",
 		Long:    "TODO",
-		Version: pkg.GetVersion(),
+		Version: pkg.FullVersion,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			configProvider, err := config.NewProvider().Load(cfgFile)
 			if err != nil {

pkg/config/config.go

@@ -7,6 +7,6 @@ import (
 
 // Config is a general top-level Glide configuration
 type Config struct {
-	Telemetry *telemetry.Config `json:"telemetry" yaml:"telemetry"`
-	API       *api.Config       `json:"api" yaml:"api"`
+	Telemetry *telemetry.Config `mapstructure:"telemetry"`
+	API       *api.Config       `mapstructure:"api"`
 }

pkg/config/expander.go

@@ -0,0 +1,71 @@
+package config
+
+const directivePattern = `[A-Za-z][A-Za-z0-9+.-]+`
+
+type RawConfig = map[string]interface{}
+
+// Expander finds special directives like ${env:ENV_VAR} in the config file and fill them with actual values
+type Expander struct{}
+
+func (e *Expander) Expand(rawConfig RawConfig) (RawConfig, error) {
+	for configKey, configValue := range rawConfig {
+		expandedValue, err := e.expandConfigValue(configValue)
+
+		if err != nil {
+			return nil, err
+		}
+
+		rawConfig[configKey] = expandedValue
+	}
+
+	return rawConfig, nil
+}
+
+func (e *Expander) expandConfigValue(value any) (any, error) {
+	switch v := value.(type) {
+	case string:
+		return e.expandString(v)
+	case []any:
+		return e.expandSlice(v)
+	case map[string]any:
+		return e.expandMap(v)
+	default:
+		// could be int or float
+		return value, nil
+	}
+}
+
+func (e *Expander) expandString(value string) (string, error) {
+	// TODO: implement
+	return value, nil
+}
+
+func (e *Expander) expandSlice(value []any) ([]any, error) {
+	slice := make([]any, 0, len(value))
+
+	for _, vint := range value {
+		val, err := e.expandConfigValue(vint)
+		if err != nil {
+			return nil, err
+		}
+
+		slice = append(slice, val)
+	}
+
+	return slice, nil
+}
+
+func (e Expander) expandMap(value map[string]any) (map[string]any, error) {
+	newMap := map[string]any{}
+
+	for mapKey, mapValue := range value {
+		val, err := e.expandConfigValue(mapValue)
+		if err != nil {
+			return nil, err
+		}
+
+		newMap[mapKey] = val
+	}
+
+	return newMap, nil
+}

pkg/config/expander_test.go

@@ -0,0 +1,36 @@
+package config
+
+import (
+	"testing"
+)
+
+func TestExpander_EnvVarExpanded(t *testing.T) {
+	var testCases = []struct {
+		name string // test case name (also file name containing config yaml)
+	}{
+		{name: "no-env.yaml"},
+		{name: "partial-env.yaml"},
+		{name: "all-env.yaml"},
+	}
+
+	const valueExtra = "some string"
+	const valueExtraMapValue = "some map value"
+	const valueExtraListMapValue = "some list map value"
+	const valueExtraListElement = "some list value"
+
+	t.Setenv("EXTRA", valueExtra)
+	t.Setenv("EXTRA_MAP_VALUE_1", valueExtraMapValue+"_1")
+	t.Setenv("EXTRA_MAP_VALUE_2", valueExtraMapValue+"_2")
+	t.Setenv("EXTRA_LIST_MAP_VALUE_1", valueExtraListMapValue+"_1")
+	t.Setenv("EXTRA_LIST_MAP_VALUE_2", valueExtraListMapValue+"_2")
+	t.Setenv("EXTRA_LIST_VALUE_1", valueExtraListElement+"_1")
+	t.Setenv("EXTRA_LIST_VALUE_2", valueExtraListElement+"_2")
+
+	for _, test := range testCases {
+		t.Run(test.name, func(t *testing.T) {
+			expander := Expander{}
+
+			modifiedConfig, err := expander.Expand()
+		})
+	}
+}

pkg/config/provider.go

@@ -5,33 +5,55 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/mitchellh/mapstructure"
+
 	"gopkg.in/yaml.v3"
 )
 
 // Provider reads, collects, validates and process config files
 type Provider struct {
-	Config *Config
+	expander *Expander
+	Config   *Config
 }
 
 // NewProvider creates a instance of Config Provider
 func NewProvider() *Provider {
 	return &Provider{
-		Config: nil,
+		expander: &Expander{},
+		Config:   nil,
 	}
 }
 
 func (p *Provider) Load(configPath string) (*Provider, error) {
-	rawConfig, err := os.ReadFile(filepath.Clean(configPath))
+	rawContent, err := os.ReadFile(filepath.Clean(configPath))
 	if err != nil {
 		return p, fmt.Errorf("unable to read the file %v: %w", configPath, err)
 	}
 
-	var cfg *Config
+	var rawConfig RawConfig
 
-	if err := yaml.Unmarshal(rawConfig, &cfg); err != nil {
+	if err := yaml.Unmarshal(rawContent, &rawConfig); err != nil {
 		return p, fmt.Errorf("unable to serialize the file %v: %w", configPath, err)
 	}
 
+	// process raw config
+	rawConfig, err = p.expander.Expand(rawConfig)
+
+	if err != nil {
+		return p, fmt.Errorf("unable to expand config directives %v: %w", configPath, err)
+	}
+
+	// validate the config structure
+	var cfg *Config
+
+	err = mapstructure.Decode(rawConfig, cfg)
+
+	if err != nil {
+		return p, err
+	}
+
+	// TODO: validate config values
+
 	p.Config = cfg
 
 	return p, nil

pkg/telemetry/logging.go

@@ -9,25 +9,25 @@ import (
 
 type LogConfig struct {
 	// Level is the minimum enabled logging level.
-	Level zap.AtomicLevel `yaml:"level"`
+	Level zap.AtomicLevel `mapstructure:"level"`
 
 	// Encoding sets the logger's encoding. Valid values are "json", "console"
-	Encoding string `yaml:"encoding"`
+	Encoding string `mapstructure:"encoding"`
 
 	// DisableCaller stops annotating logs with the calling function's file name and line number.
 	// By default, all logs are annotated.
-	DisableCaller bool `yaml:"disable_caller"`
+	DisableCaller bool `mapstructure:"disable_caller"`
 
 	// DisableStacktrace completely disables automatic stacktrace capturing. By
 	// default, stacktraces are captured for WarnLevel and above logs in
 	// development and ErrorLevel and above in production.
-	DisableStacktrace bool `yaml:"disable_stacktrace"`
+	DisableStacktrace bool `mapstructure:"disable_stacktrace"`
 
 	// OutputPaths is a list of URLs or file paths to write logging output to.
-	OutputPaths []string `yaml:"output_paths"`
+	OutputPaths []string `mapstructure:"output_paths"`
 
 	// InitialFields is a collection of fields to add to the root logger.
-	InitialFields map[string]interface{} `yaml:"initial_fields"`
+	InitialFields map[string]interface{} `mapstructure:"initial_fields"`
 }
 
 func NewLogConfig() *LogConfig {

pkg/telemetry/telemetry.go

@@ -3,7 +3,7 @@ package telemetry
 import "go.uber.org/zap"
 
 type Config struct {
-	LogConfig *LogConfig `json:"logging" yaml:"logging"`
+	LogConfig *LogConfig `mapstructure:"logging"`
 	// TODO: add OTEL config
 }
 

pkg/version.go

@@ -13,6 +13,8 @@ var version = "devel"
 // and will be populated by the Makefile
 var commitSha = "unknown"
 
-func GetVersion() string {
-	return fmt.Sprintf("%s (commit: %s, %s)", version, commitSha, runtime.Version())
+var FullVersion string
+
+func init() {
+	FullVersion = fmt.Sprintf("%s (commit: %s, %s)", version, commitSha, runtime.Version())
 }