Merge pull request #42 from unistack-org/usage

using own usage func

flag.go

@@ -5,7 +5,9 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"os"
 	"reflect"
+	"strings"
 	"time"
 
 	"go.unistack.org/micro/v3/config"
@@ -27,7 +29,10 @@ var (
 */
 
 type flagConfig struct {
+	fset *flag.FlagSet
 	opts config.Options
+	name string
+	env  string
 }
 
 func (c *flagConfig) Options() config.Options {
@@ -38,6 +43,7 @@ func (c *flagConfig) Init(opts ...config.Option) error {
 	for _, o := range opts {
 		o(&c.opts)
 	}
+	c.configure()
 
 	fields, err := rutil.StructFields(c.opts.Struct)
 	if err != nil {
@@ -49,7 +55,11 @@ func (c *flagConfig) Init(opts ...config.Option) error {
 		if !ok {
 			continue
 		}
+
 		fn, fd, fv := getFlagOpts(tf)
+		if tf, ok = sf.Field.Tag.Lookup(c.env); ok {
+			fd += fmt.Sprintf(" (env %s)", tf)
+		}
 
 		rcheck := true
 
@@ -63,6 +73,7 @@ func (c *flagConfig) Init(opts ...config.Option) error {
 		if f := flag.Lookup(fn); f != nil {
 			return nil
 		}
+
 		switch vi.(type) {
 		case time.Duration:
 			err = c.flagDuration(sf.Value, fn, fv, fd)
@@ -144,10 +155,125 @@ func (c *flagConfig) Watch(ctx context.Context, opts ...config.WatchOption) (con
 	return nil, fmt.Errorf("not implemented")
 }
 
+func (c *flagConfig) usage() {
+	mapDelim := DefaultMapDelim
+	sliceDelim := DefaultSliceDelim
+
+	if c.opts.Context != nil {
+		if d, ok := c.opts.Context.Value(mapDelimKey{}).(string); ok {
+			mapDelim = d
+		}
+		if d, ok := c.opts.Context.Value(sliceDelimKey{}).(string); ok {
+			sliceDelim = d
+		}
+	}
+
+	if c.name == "" {
+		fmt.Fprintf(c.fset.Output(), "Usage:\n")
+	} else {
+		fmt.Fprintf(c.fset.Output(), "Usage of %s:\n", c.name)
+	}
+
+	c.fset.VisitAll(func(f *flag.Flag) {
+		var b strings.Builder
+		fmt.Fprintf(&b, "  -%s", f.Name) // Two spaces before -; see next two comments.
+		_, usage := flag.UnquoteUsage(f)
+		name := "value"
+		v := reflect.TypeOf(f.Value).String()
+		b.WriteString(" ")
+		switch v {
+		case "*flag.boolFlag":
+			name = "bool"
+		case "*flag.durationValue":
+			name = "duration"
+		case "*flag.float64Value":
+			name = "float"
+		case "*flag.intValue", "*flag.int64Value":
+			name = "int"
+		case "*flag.stringValue":
+			name = "string"
+		case "*flag.uintValue", "*flag.uint64Value":
+			name = "uint"
+		case "*flag.mapValue":
+			//	nv := f.Value.(*mapValue)
+			name = fmt.Sprintf("string key=val with %q as separator", mapDelim)
+		case "*flag.sliceValue":
+			//	nv := f.Value.(*sliceValue)
+			name = fmt.Sprintf("string with %q as separator", sliceDelim)
+		}
+		b.WriteString(name)
+
+		// Boolean flags of one ASCII letter are so common we
+		// treat them specially, putting their usage on the same line.
+		if b.Len() <= 4 { // space, space, '-', 'x'.
+			b.WriteString("\t")
+		} else {
+			// Four spaces before the tab triggers good alignment
+			// for both 4- and 8-space tab stops.
+			b.WriteString("\n    \t")
+		}
+		b.WriteString(strings.ReplaceAll(usage, "\n", "\n    \t"))
+
+		if f.Value.String() == f.DefValue {
+			fmt.Fprintf(&b, " (default %q)", f.DefValue)
+		} else {
+			fmt.Fprintf(&b, " (default %q current %q)", f.DefValue, f.Value)
+		}
+
+		fmt.Fprint(c.fset.Output(), b.String(), "\n")
+	})
+}
+
+func (c *flagConfig) configure() {
+	flagSet := flag.CommandLine
+	flagSetName := os.Args[0]
+	flagSetErrorHandling := flag.ExitOnError
+	flagEnv := "env"
+	var flagUsage func()
+	var isSet bool
+
+	if c.opts.Context != nil {
+		if v, ok := c.opts.Context.Value(flagSetNameKey{}).(string); ok {
+			isSet = true
+			flagSetName = v
+		}
+		if v, ok := c.opts.Context.Value(flagSetErrorHandlingKey{}).(flag.ErrorHandling); ok {
+			isSet = true
+			flagSetErrorHandling = v
+		}
+		if v, ok := c.opts.Context.Value(flagSetKey{}).(*flag.FlagSet); ok {
+			flagSet = v
+		}
+		if v, ok := c.opts.Context.Value(flagSetUsageKey{}).(func()); ok {
+			flagUsage = v
+		}
+		if v, ok := c.opts.Context.Value(flagEnvKey{}).(string); ok {
+			flagEnv = v
+		}
+	}
+	c.fset = flagSet
+
+	if isSet {
+		c.fset.Init(flagSetName, flagSetErrorHandling)
+	}
+	if flagUsage != nil {
+		c.fset.Usage = flagUsage
+	} else {
+		c.fset.Usage = c.usage
+	}
+	c.env = flagEnv
+
+	c.name = flagSetName
+}
+
 func NewConfig(opts ...config.Option) config.Config {
 	options := config.NewOptions(opts...)
 	if len(options.StructTag) == 0 {
 		options.StructTag = DefaultStructTag
 	}
-	return &flagConfig{opts: options}
+
+	c := &flagConfig{opts: options}
+	c.configure()
+
+	return c
 }

flag_test.go

@@ -2,6 +2,7 @@ package flag
 
 import (
 	"context"
+	"flag"
 	"os"
 	"testing"
 	"time"
@@ -18,27 +19,29 @@ func TestLoad(t *testing.T) {
 	os.Args = append(os.Args, "-time", time.RFC822)
 	os.Args = append(os.Args, "-metadata", "key=20")
 	os.Args = append(os.Args, "-components", "all=info,api=debug")
+	os.Args = append(os.Args, "-addr", "33,44")
+	os.Args = append(os.Args, "-badflag", "test")
 	type NestedConfig struct {
 		Value string `flag:"name=nested_value"`
 	}
 	type Config struct {
-		Broker         string            `flag:"name=broker,desc='description with, comma',default='127.0.0.1:9092'"`
-		Verbose        bool              `flag:"name=verbose,desc='verbose output',default='false'"`
-		Addr           []string          `flag:"name=addr,desc='addrs',default='127.0.0.1:9092'"`
-		Wait           time.Duration     `flag:"name=wait,desc='wait time',default='2s'"`
 		Time           time.Time         `flag:"name=time,desc='some time',default='02 Jan 06 15:04 MST'"`
-		Metadata       map[string]int    `flag:"name=metadata,desc='some meta',default=''"`
-		WithoutDefault string            `flag:"name=without_default,desc='with'"`
-		WithoutDesc    string            `flag:"name=without_desc,default='without_default'"`
-		WithoutAll     string            `flag:"name=without_all"`
 		Components     map[string]string `flag:"name=components,desc='components logging'"`
+		Metadata       map[string]int    `flag:"name=metadata,desc='some meta',default=''"`
 		Nested         *NestedConfig
+		Broker         string        `flag:"name=broker,desc='description with, comma',default='127.0.0.1:9092'"`
+		WithoutDesc    string        `flag:"name=without_desc,default='without_default'"`
+		WithoutAll     string        `flag:"name=without_all"`
+		WithoutDefault string        `flag:"name=without_default,desc='with'"`
+		Addr           []string      `flag:"name=addr,desc='addrs',default='127.0.0.1:9092'"`
+		Wait           time.Duration `flag:"name=wait,desc='wait time',default='2s'"`
+		Verbose        bool          `flag:"name=verbose,desc='verbose output',default='false'"`
 	}
 
 	ctx := context.Background()
 	cfg := &Config{Nested: &NestedConfig{}}
 
-	c := NewConfig(config.Struct(cfg), TimeFormat(time.RFC822))
+	c := NewConfig(config.Struct(cfg), TimeFormat(time.RFC822), FlagErrorHandling(flag.ContinueOnError))
 	if err := c.Init(); err != nil {
 		t.Fatalf("init failed: %v", err)
 	}

go.mod

@@ -2,4 +2,4 @@ module go.unistack.org/micro-config-flag/v3
 
 go 1.16
 
-require go.unistack.org/micro/v3 v3.9.1
+require go.unistack.org/micro/v3 v3.9.7

go.sum

@@ -22,7 +22,7 @@ github.com/envoyproxy/go-control-plane v0.9.9-0.20210512163311-63b5d3c536b0/go.m
 github.com/envoyproxy/protoc-gen-validate v0.1.0/go.mod h1:iSmxcyjqTsJpI2R4NaDN7+kN2VEUnK/pcBlmesArF7c=
 github.com/flowstack/go-jsonschema v0.1.1/go.mod h1:yL7fNggx1o8rm9RlgXv7hTBWxdBM0rVwpMwimd3F3N0=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
-github.com/golang-jwt/jwt/v4 v4.4.0/go.mod h1:/xlHOz8bRuivTWchD4jCa+NbatV+wEUSzwAxVc6locg=
+github.com/golang-jwt/jwt/v4 v4.4.1/go.mod h1:m21LjoU+eqJr34lmDMbreY2eSTRJ1cv77w39/MY0Ch0=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
@@ -73,8 +73,8 @@ github.com/xeipuuv/gojsonschema v1.2.0/go.mod h1:anYRn/JVcOK2ZgGU+IjEV4nwlhoK5sQ
 go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqeYNgFYFoEGnI=
 go.unistack.org/micro-proto/v3 v3.2.7 h1:zG6d69kHc+oij2lwQ3AfrCgdjiEVRG2A7TlsxjusWs4=
 go.unistack.org/micro-proto/v3 v3.2.7/go.mod h1:ZltVWNECD5yK+40+OCONzGw4OtmSdTpVi8/KFgo9dqM=
-go.unistack.org/micro/v3 v3.9.1 h1:C1TEP8Eooqr5vlNLoZ3LCpNqk+XuCiC1yBHol+qJZ4E=
-go.unistack.org/micro/v3 v3.9.1/go.mod h1:7ssIWk+PJXvb2nSl8NUnQRs32JJEId2IDi9PobrQlKo=
+go.unistack.org/micro/v3 v3.9.7 h1:ROx4X6nP9rE72lKgawyys/8VdNXqU65fb3he7d00iZk=
+go.unistack.org/micro/v3 v3.9.7/go.mod h1:E1pmj0cNC7P+QVX1sElRBMiNaQVTjDoEtYlbqZY84c4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=

options.go

@@ -1,6 +1,8 @@
 package flag
 
 import (
+	"flag"
+
 	"go.unistack.org/micro/v3/config"
 )
 
@@ -24,3 +26,39 @@ type timeFormatKey struct{}
 func TimeFormat(s string) config.Option {
 	return config.SetOption(timeFormatKey{}, s)
 }
+
+type flagSetKey struct{}
+
+// FlagSet set flag set name
+func FlagSet(f *flag.FlagSet) config.Option {
+	return config.SetOption(flagSetKey{}, f)
+}
+
+type flagSetNameKey struct{}
+
+// FlagSetName set flag set name
+func FlagSetName(n string) config.Option {
+	return config.SetOption(flagSetNameKey{}, n)
+}
+
+type flagSetErrorHandlingKey struct{}
+
+// FlagErrorHandling set flag set error handling
+func FlagErrorHandling(eh flag.ErrorHandling) config.Option {
+	return config.SetOption(flagSetErrorHandlingKey{}, eh)
+}
+
+type flagSetUsageKey struct{}
+
+// FlagUsage set flag set usage func
+func FlagUsage(fn func()) config.Option {
+	return config.SetOption(flagSetUsageKey{}, fn)
+}
+
+
+type flagEnvKey struct{}
+
+// FlagEnv set flag set usage func
+func FlagEnv(n string) config.Option {
+	return config.SetOption(flagEnvKey{}, n)
+}

util.go

@@ -10,12 +10,12 @@ import (
 )
 
 type mapValue struct {
-	v     reflect.Value
 	delim string
 	def   string
+	v     reflect.Value
 }
 
-func (v mapValue) String() string {
+func (v *mapValue) String() string {
 	if v.v.Kind() != reflect.Invalid {
 		var kv []string
 		it := v.v.MapRange()
@@ -29,7 +29,11 @@ func (v mapValue) String() string {
 	return v.def
 }
 
-func (v mapValue) Set(s string) error {
+func (v *mapValue) Get() interface{} {
+	return v.v.Interface()
+}
+
+func (v *mapValue) Set(s string) error {
 	ps := strings.Split(s, v.delim)
 	if len(ps) == 0 {
 		return nil
@@ -67,12 +71,12 @@ func (v mapValue) Set(s string) error {
 }
 
 type sliceValue struct {
-	v     reflect.Value
 	delim string
 	def   string
+	v     reflect.Value
 }
 
-func (v sliceValue) String() string {
+func (v *sliceValue) String() string {
 	if v.v.Kind() != reflect.Invalid {
 		var kv []string
 		for idx := 0; idx < v.v.Len(); idx++ {
@@ -83,7 +87,11 @@ func (v sliceValue) String() string {
 	return v.def
 }
 
-func (v sliceValue) Set(s string) error {
+func (v *sliceValue) Get() interface{} {
+	return v.v.Interface()
+}
+
+func (v *sliceValue) Set(s string) error {
 	p := strings.Split(s, v.delim)
 	v.v.Set(reflect.MakeSlice(v.v.Type(), len(p), len(p)))
 	switch v.v.Type().Elem().Kind() {