logger: add wrapper support

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

broker/broker.go

@@ -3,6 +3,7 @@ package broker
 
 import (
 	"context"
+	"errors"
 
 	"github.com/unistack-org/micro/v3/metadata"
 )
@@ -34,10 +35,31 @@ type Event interface {
 	Error() error
 }
 
+// RawMessage is a raw encoded JSON value.
+// It implements Marshaler and Unmarshaler and can be used to delay decoding or precompute a encoding.
+type RawMessage []byte
+
+// MarshalJSON returns m as the JSON encoding of m.
+func (m *RawMessage) MarshalJSON() ([]byte, error) {
+	if m == nil {
+		return []byte("null"), nil
+	}
+	return *m, nil
+}
+
+// UnmarshalJSON sets *m to a copy of data.
+func (m *RawMessage) UnmarshalJSON(data []byte) error {
+	if m == nil {
+		return errors.New("RawMessage UnmarshalJSON on nil pointer")
+	}
+	*m = append((*m)[0:0], data...)
+	return nil
+}
+
 // Message is used to transfer data
 type Message struct {
 	Header metadata.Metadata // contains message metadata
-	Body   []byte            // contains message body
+	Body   RawMessage        // contains message body
 }
 
 // Subscriber is a convenience return type for the Subscribe method

broker/memory_test.go

@@ -32,7 +32,7 @@ func TestMemoryBroker(t *testing.T) {
 				"foo": "bar",
 				"id":  fmt.Sprintf("%d", i),
 			},
-			Body: []byte(`hello world`),
+			Body: []byte(`"hello world"`),
 		}
 
 		if err := b.Publish(ctx, topic, message); err != nil {

config/config.go

@@ -43,13 +43,13 @@ type Watcher interface {
 }
 
 // Load loads config from config sources
-func Load(ctx context.Context, cs ...Config) error {
+func Load(ctx context.Context, cs []Config, opts ...LoadOption) error {
 	var err error
 	for _, c := range cs {
 		if err = c.Init(); err != nil {
 			return err
 		}
-		if err = c.Load(ctx); err != nil {
+		if err = c.Load(ctx, opts...); err != nil {
 			return err
 		}
 	}

flow/context.go

@@ -0,0 +1,34 @@
+package flow
+
+import (
+	"context"
+)
+
+type flowKey struct{}
+
+// FromContext returns Flow from context
+func FromContext(ctx context.Context) (Flow, bool) {
+	if ctx == nil {
+		return nil, false
+	}
+	c, ok := ctx.Value(flowKey{}).(Flow)
+	return c, ok
+}
+
+// NewContext stores Flow to context
+func NewContext(ctx context.Context, f Flow) context.Context {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	return context.WithValue(ctx, flowKey{}, f)
+}
+
+// SetOption returns a function to setup a context with given value
+func SetOption(k, v interface{}) Option {
+	return func(o *Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}

flow/default.go

@@ -0,0 +1,319 @@
+package flow
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"github.com/google/uuid"
+	"github.com/silas/dag"
+	"github.com/unistack-org/micro/v3/client"
+	"github.com/unistack-org/micro/v3/codec"
+)
+
+type microFlow struct {
+	opts Options
+}
+
+type microWorkflow struct {
+	id   string
+	g    *dag.AcyclicGraph
+	init bool
+	sync.RWMutex
+	opts  Options
+	steps map[string]Step
+}
+
+func (w *microWorkflow) ID() string {
+	return w.id
+}
+
+func (w *microWorkflow) Steps() [][]Step {
+	return nil
+}
+
+func (w *microWorkflow) AppendSteps(ctx context.Context, steps ...Step) error {
+	return nil
+}
+
+func (w *microWorkflow) RemoveSteps(ctx context.Context, steps ...Step) error {
+	return nil
+}
+
+func (w *microWorkflow) Execute(ctx context.Context, req interface{}, opts ...ExecuteOption) (string, error) {
+	w.Lock()
+	if !w.init {
+		if err := w.g.Validate(); err != nil {
+			w.Unlock()
+			return "", err
+		}
+		w.g.TransitiveReduction()
+		w.init = true
+	}
+	w.Unlock()
+
+	uid, err := uuid.NewRandom()
+	if err != nil {
+		return "", err
+	}
+
+	options := NewExecuteOptions(opts...)
+	var steps [][]Step
+	fn := func(n dag.Vertex, idx int) error {
+		if idx == 0 {
+			steps = make([][]Step, 1)
+			steps[0] = make([]Step, 0, 1)
+		} else if idx >= len(steps) {
+			tsteps := make([][]Step, idx+1)
+			copy(tsteps, steps)
+			steps = tsteps
+			steps[idx] = make([]Step, 0, 1)
+		}
+		steps[idx] = append(steps[idx], n.(Step))
+		return nil
+	}
+
+	var root dag.Vertex
+	if options.Start != "" {
+		var ok bool
+		w.RLock()
+		root, ok = w.steps[options.Start]
+		w.RUnlock()
+		if !ok {
+			return "", ErrStepNotExists
+		}
+	} else {
+		root, err = w.g.Root()
+		if err != nil {
+			return "", err
+		}
+	}
+	if options.Reverse {
+		err = w.g.SortedReverseDepthFirstWalk([]dag.Vertex{root}, fn)
+	} else {
+		err = w.g.SortedDepthFirstWalk([]dag.Vertex{root}, fn)
+	}
+	if err != nil {
+		return "", err
+	}
+
+	var wg sync.WaitGroup
+	cherr := make(chan error, 1)
+	defer close(cherr)
+
+	nctx, cancel := context.WithCancel(ctx)
+	defer cancel()
+	nopts := make([]ExecuteOption, 0, len(opts)+5)
+	nopts = append(nopts, ExecuteClient(w.opts.Client), ExecuteTracer(w.opts.Tracer), ExecuteLogger(w.opts.Logger), ExecuteMeter(w.opts.Meter), ExecuteStore(w.opts.Store))
+
+	go func() {
+		for idx := range steps {
+			wg.Add(len(steps[idx]))
+			for nidx := range steps[idx] {
+				go func(step Step) {
+					defer wg.Done()
+					if err = step.Execute(nctx, req, nopts...); err != nil {
+						cherr <- err
+						cancel()
+					}
+				}(steps[idx][nidx])
+			}
+			wg.Wait()
+		}
+		cherr <- nil
+	}()
+
+	err = <-cherr
+
+	return uid.String(), err
+}
+
+func NewFlow(opts ...Option) Flow {
+	options := NewOptions(opts...)
+	return &microFlow{opts: options}
+}
+
+func (f *microFlow) Options() Options {
+	return f.opts
+}
+
+func (f *microFlow) Init(opts ...Option) error {
+	for _, o := range opts {
+		o(&f.opts)
+	}
+	if err := f.opts.Client.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Tracer.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Logger.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Meter.Init(); err != nil {
+		return err
+	}
+	if err := f.opts.Store.Init(); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (f *microFlow) WorkflowList(ctx context.Context) ([]Workflow, error) {
+	return nil, nil
+}
+
+func (f *microFlow) WorkflowCreate(ctx context.Context, id string, steps ...Step) (Workflow, error) {
+	w := &microWorkflow{opts: f.opts, id: id, g: &dag.AcyclicGraph{}, steps: make(map[string]Step, len(steps))}
+
+	for _, s := range steps {
+		w.steps[s.String()] = s
+		w.g.Add(s)
+	}
+
+	for _, dst := range steps {
+		for _, req := range dst.Requires() {
+			src, ok := w.steps[req]
+			if !ok {
+				return nil, ErrStepNotExists
+			}
+			w.g.Connect(dag.BasicEdge(src, dst))
+		}
+	}
+
+	if err := w.g.Validate(); err != nil {
+		return nil, err
+	}
+	w.g.TransitiveReduction()
+
+	w.init = true
+
+	return w, nil
+}
+
+func (f *microFlow) WorkflowRemove(ctx context.Context, id string) error {
+	return nil
+}
+
+func (f *microFlow) WorkflowSave(ctx context.Context, w Workflow) error {
+	return nil
+}
+
+func (f *microFlow) WorkflowLoad(ctx context.Context, id string) (Workflow, error) {
+	return nil, nil
+}
+
+type microCallStep struct {
+	opts    StepOptions
+	service string
+	method  string
+}
+
+func (s *microCallStep) ID() string {
+	return s.String()
+}
+
+func (s *microCallStep) Options() StepOptions {
+	return s.opts
+}
+
+func (s *microCallStep) Endpoint() string {
+	return s.method
+}
+
+func (s *microCallStep) Requires() []string {
+	return s.opts.Requires
+}
+
+func (s *microCallStep) Require(steps ...Step) error {
+	for _, step := range steps {
+		s.opts.Requires = append(s.opts.Requires, step.String())
+	}
+	return nil
+}
+
+func (s *microCallStep) String() string {
+	if s.opts.ID != "" {
+		return s.opts.ID
+	}
+	return fmt.Sprintf("%s.%s", s.service, s.method)
+}
+
+func (s *microCallStep) Name() string {
+	return s.String()
+}
+
+func (s *microCallStep) Hashcode() interface{} {
+	return s.String()
+}
+
+func (s *microCallStep) Execute(ctx context.Context, req interface{}, opts ...ExecuteOption) error {
+	options := NewExecuteOptions(opts...)
+	if options.Client == nil {
+		return fmt.Errorf("client not set")
+	}
+	rsp := &codec.Frame{}
+	copts := []client.CallOption{client.WithRetries(0)}
+	if options.Timeout > 0 {
+		copts = append(copts, client.WithRequestTimeout(options.Timeout), client.WithDialTimeout(options.Timeout))
+	}
+	err := options.Client.Call(ctx, options.Client.NewRequest(s.service, s.method, req), rsp)
+	return err
+}
+
+type microPublishStep struct {
+	opts  StepOptions
+	topic string
+}
+
+func (s *microPublishStep) ID() string {
+	return s.String()
+}
+
+func (s *microPublishStep) Options() StepOptions {
+	return s.opts
+}
+
+func (s *microPublishStep) Endpoint() string {
+	return s.topic
+}
+
+func (s *microPublishStep) Requires() []string {
+	return s.opts.Requires
+}
+
+func (s *microPublishStep) Require(steps ...Step) error {
+	for _, step := range steps {
+		s.opts.Requires = append(s.opts.Requires, step.String())
+	}
+	return nil
+}
+
+func (s *microPublishStep) String() string {
+	if s.opts.ID != "" {
+		return s.opts.ID
+	}
+	return fmt.Sprintf("%s", s.topic)
+}
+
+func (s *microPublishStep) Name() string {
+	return s.String()
+}
+
+func (s *microPublishStep) Hashcode() interface{} {
+	return s.String()
+}
+
+func (s *microPublishStep) Execute(ctx context.Context, req interface{}, opts ...ExecuteOption) error {
+	return nil
+}
+
+func NewCallStep(service string, method string, opts ...StepOption) Step {
+	options := NewStepOptions(opts...)
+	return &microCallStep{service: service, method: method, opts: options}
+}
+
+func NewPublishStep(topic string, opts ...StepOption) Step {
+	options := NewStepOptions(opts...)
+	return &microPublishStep{topic: topic, opts: options}
+}

flow/flow.go

@@ -1,17 +1,59 @@
 // Package flow is an interface used for saga pattern microservice workflow
 package flow
 
+import (
+	"context"
+	"errors"
+)
+
+var (
+	ErrStepNotExists = errors.New("step not exists")
+)
+
+// Step represents dedicated workflow step
 type Step interface {
+	// ID returns step id
+	ID() string
 	// Endpoint returns rpc endpoint service_name.service_method or broker topic
 	Endpoint() string
+	// Execute step run
+	Execute(ctx context.Context, req interface{}, opts ...ExecuteOption) error
+	// Requires returns dependent steps
+	Requires() []string
+	// Options returns step options
+	Options() StepOptions
+	// Require add required steps
+	Require(steps ...Step) error
+	// String
+	String() string
 }
 
+// Workflow contains all steps to execute
 type Workflow interface {
+	// ID returns id of the workflow
+	ID() string
+	// Steps returns steps slice where parallel steps returned on the same level
 	Steps() [][]Step
-	Stop() error
+	// Execute workflow with args, return execution id and error
+	Execute(ctx context.Context, req interface{}, opts ...ExecuteOption) (string, error)
+	// RemoveSteps remove steps from workflow
+	RemoveSteps(ctx context.Context, steps ...Step) error
+	// AppendSteps append steps to workflow
+	AppendSteps(ctx context.Context, steps ...Step) error
 }
 
+// Flow the base interface to interact with workflows
 type Flow interface {
-	Start(Workflow) error
-	Stop(Workflow)
+	// Options returns options
+	Options() Options
+	// Init initialize
+	Init(...Option) error
+	// WorkflowCreate creates new workflow with specific id and steps
+	WorkflowCreate(ctx context.Context, id string, steps ...Step) (Workflow, error)
+	// WorkflowSave saves workflow
+	WorkflowSave(ctx context.Context, w Workflow) error
+	// WorkflowLoad loads workflow with specific id
+	WorkflowLoad(ctx context.Context, id string) (Workflow, error)
+	// WorkflowList lists all workflows
+	WorkflowList(ctx context.Context) ([]Workflow, error)
 }

flow/options.go

@@ -0,0 +1,222 @@
+package flow
+
+import (
+	"context"
+	"time"
+
+	"github.com/unistack-org/micro/v3/client"
+	"github.com/unistack-org/micro/v3/logger"
+	"github.com/unistack-org/micro/v3/meter"
+	"github.com/unistack-org/micro/v3/store"
+	"github.com/unistack-org/micro/v3/tracer"
+)
+
+// Option func
+type Option func(*Options)
+
+// Options server struct
+type Options struct {
+	// Context holds the external options and can be used for flow shutdown
+	Context context.Context
+	// Client holds the client.Client
+	Client client.Client
+	// Tracer holds the tracer
+	Tracer tracer.Tracer
+	// Logger holds the logger
+	Logger logger.Logger
+	// Meter holds the meter
+	Meter meter.Meter
+	// Store used for intermediate results
+	Store store.Store
+}
+
+// NewOptions returns new options struct with default or passed values
+func NewOptions(opts ...Option) Options {
+	options := Options{
+		Context: context.Background(),
+		Logger:  logger.DefaultLogger,
+		Meter:   meter.DefaultMeter,
+		Tracer:  tracer.DefaultTracer,
+		Client:  client.DefaultClient,
+	}
+
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return options
+}
+
+// Logger sets the logger option
+func Logger(l logger.Logger) Option {
+	return func(o *Options) {
+		o.Logger = l
+	}
+}
+
+// Meter sets the meter option
+func Meter(m meter.Meter) Option {
+	return func(o *Options) {
+		o.Meter = m
+	}
+}
+
+// Client to use for sync/async communication
+func Client(c client.Client) Option {
+	return func(o *Options) {
+		o.Client = c
+	}
+}
+
+// Context specifies a context for the service.
+// Can be used to signal shutdown of the flow
+// Can be used for extra option values.
+func Context(ctx context.Context) Option {
+	return func(o *Options) {
+		o.Context = ctx
+	}
+}
+
+// Tracer mechanism for distributed tracking
+func Tracer(t tracer.Tracer) Option {
+	return func(o *Options) {
+		o.Tracer = t
+	}
+}
+
+// Store used for intermediate results
+func Store(s store.Store) Option {
+	return func(o *Options) {
+		o.Store = s
+	}
+}
+
+// WorflowOption signature
+type WorkflowOption func(*WorkflowOptions)
+
+// WorkflowOptions holds workflow options
+type WorkflowOptions struct {
+	ID      string
+	Context context.Context
+}
+
+// WorkflowID set workflow id
+func WorkflowID(id string) WorkflowOption {
+	return func(o *WorkflowOptions) {
+		o.ID = id
+	}
+}
+
+type ExecuteOptions struct {
+	// Client holds the client.Client
+	Client client.Client
+	// Tracer holds the tracer
+	Tracer tracer.Tracer
+	// Logger holds the logger
+	Logger logger.Logger
+	// Meter holds the meter
+	Meter meter.Meter
+	// Store used for intermediate results
+	Store store.Store
+	// Context can be used to abort execution or pass additional opts
+	Context context.Context
+	// Start step
+	Start string
+	// Reverse execution
+	Reverse bool
+	// Timeout for execution
+	Timeout time.Duration
+}
+
+type ExecuteOption func(*ExecuteOptions)
+
+func ExecuteClient(c client.Client) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Client = c
+	}
+}
+
+func ExecuteTracer(t tracer.Tracer) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Tracer = t
+	}
+}
+
+func ExecuteLogger(l logger.Logger) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Logger = l
+	}
+}
+
+func ExecuteMeter(m meter.Meter) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Meter = m
+	}
+}
+
+func ExecuteStore(s store.Store) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Store = s
+	}
+}
+
+func ExecuteContext(ctx context.Context) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Context = ctx
+	}
+}
+
+func ExecuteReverse(b bool) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Reverse = b
+	}
+}
+
+func ExecuteTimeout(td time.Duration) ExecuteOption {
+	return func(o *ExecuteOptions) {
+		o.Timeout = td
+	}
+}
+
+func NewExecuteOptions(opts ...ExecuteOption) ExecuteOptions {
+	options := ExecuteOptions{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+type StepOptions struct {
+	ID       string
+	Context  context.Context
+	Requires []string
+	Fallback string
+}
+
+type StepOption func(*StepOptions)
+
+func NewStepOptions(opts ...StepOption) StepOptions {
+	options := StepOptions{Context: context.Background()}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+func StepID(id string) StepOption {
+	return func(o *StepOptions) {
+		o.ID = id
+	}
+}
+
+func StepRequires(steps ...string) StepOption {
+	return func(o *StepOptions) {
+		o.Requires = steps
+	}
+}
+
+func StepFallback(step string) StepOption {
+	return func(o *StepOptions) {
+		o.Fallback = step
+	}
+}

logger/default.go

@@ -24,6 +24,8 @@ type defaultLogger struct {
 	enc  *json.Encoder
 	opts Options
 	sync.RWMutex
+	logFunc  LogFunc
+	logfFunc LogfFunc
 }
 
 // Init(opts...) should only overwrite provided options
@@ -33,6 +35,15 @@ func (l *defaultLogger) Init(opts ...Option) error {
 		o(&l.opts)
 	}
 	l.enc = json.NewEncoder(l.opts.Out)
+
+	l.logFunc = l.Log
+	l.logfFunc = l.Logf
+	// wrap the Log func
+	for i := len(l.opts.Wrappers); i > 0; i-- {
+		l.logFunc = l.opts.Wrappers[i-1].Log(l.logFunc)
+		l.logfFunc = l.opts.Wrappers[i-1].Logf(l.logfFunc)
+	}
+
 	l.Unlock()
 	return nil
 }
@@ -121,27 +132,27 @@ func (l *defaultLogger) Fatal(ctx context.Context, args ...interface{}) {
 }
 
 func (l *defaultLogger) Infof(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, InfoLevel, msg, args...)
+	l.logfFunc(ctx, InfoLevel, msg, args...)
 }
 
 func (l *defaultLogger) Errorf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, ErrorLevel, msg, args...)
+	l.logfFunc(ctx, ErrorLevel, msg, args...)
 }
 
 func (l *defaultLogger) Debugf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, DebugLevel, msg, args...)
+	l.logfFunc(ctx, DebugLevel, msg, args...)
 }
 
 func (l *defaultLogger) Warnf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, WarnLevel, msg, args...)
+	l.logfFunc(ctx, WarnLevel, msg, args...)
 }
 
 func (l *defaultLogger) Tracef(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, TraceLevel, msg, args...)
+	l.logfFunc(ctx, TraceLevel, msg, args...)
 }
 
 func (l *defaultLogger) Fatalf(ctx context.Context, msg string, args ...interface{}) {
-	l.Logf(ctx, FatalLevel, msg, args...)
+	l.logfFunc(ctx, FatalLevel, msg, args...)
 	os.Exit(1)
 }
 

logger/logger_test.go

@@ -1,6 +1,7 @@
 package logger
 
 import (
+	"bytes"
 	"context"
 	"testing"
 )
@@ -16,3 +17,21 @@ func TestLogger(t *testing.T) {
 	l.Fields(map[string]interface{}{"error": "test"}).Info(ctx, "error message")
 	l.Warn(ctx, "first", " ", "second")
 }
+
+func TestLoggerWrapper(t *testing.T) {
+	ctx := context.TODO()
+	buf := bytes.NewBuffer(nil)
+	l := NewLogger(WithLevel(TraceLevel), WithOutput(buf))
+	if err := l.Init(WrapLogger(NewOmitWrapper())); err != nil {
+		t.Fatal(err)
+	}
+	type secret struct {
+		Name  string
+		Passw string `logger:"omit"`
+	}
+	s := &secret{Name: "name", Passw: "secret"}
+	l.Errorf(ctx, "test %#+v", s)
+	if !bytes.Contains(buf.Bytes(), []byte(`logger.secret{Name:\"name\", Passw:\"\"}"`)) {
+		t.Fatalf("omit not works, struct: %v, output: %s", s, buf.Bytes())
+	}
+}

logger/options.go

@@ -23,6 +23,8 @@ type Options struct {
 	CallerSkipCount int
 	// The logging level the logger should log
 	Level Level
+	// Wrappers logger wrapper that called before actual Log/Logf function
+	Wrappers []Wrapper
 }
 
 // NewOptions creates new options struct
@@ -81,3 +83,10 @@ func WithName(n string) Option {
 		o.Name = n
 	}
 }
+
+// WrapLogger adds a logger Wrapper to a list of options passed into the logger
+func WrapLogger(w Wrapper) Option {
+	return func(o *Options) {
+		o.Wrappers = append(o.Wrappers, w)
+	}
+}

logger/wrapper.go

@@ -0,0 +1,68 @@
+package logger
+
+import (
+	"context"
+	"reflect"
+
+	rutil "github.com/unistack-org/micro/v3/util/reflect"
+)
+
+// LogFunc function used for Log method
+type LogFunc func(ctx context.Context, level Level, args ...interface{})
+
+// LogfFunc function used for Logf method
+type LogfFunc func(ctx context.Context, level Level, msg string, args ...interface{})
+
+type Wrapper interface {
+	// Log logs message with needed level
+	Log(LogFunc) LogFunc
+	//	Log(ctx context.Context, level Level, args ...interface{})
+	// Logf logs message with needed level
+	Logf(LogfFunc) LogfFunc
+	//Logf(ctx context.Context, level Level, msg string, args ...interface{})
+}
+
+type OmitWrapper struct{}
+
+func NewOmitWrapper() Wrapper {
+	return &OmitWrapper{}
+}
+
+func getArgs(args []interface{}) []interface{} {
+	nargs := make([]interface{}, 0, len(args))
+	var err error
+	for _, arg := range args {
+		val := reflect.ValueOf(arg)
+		switch val.Kind() {
+		case reflect.Ptr:
+			val = val.Elem()
+		}
+		narg := arg
+		if val.Kind() == reflect.Struct {
+			if narg, err = rutil.Zero(arg); err == nil {
+				rutil.CopyDefaults(narg, arg)
+				if flds, ferr := rutil.StructFields(narg); ferr == nil {
+					for _, fld := range flds {
+						if tv, ok := fld.Field.Tag.Lookup("logger"); ok && tv == "omit" {
+							fld.Value.Set(reflect.Zero(fld.Value.Type()))
+						}
+					}
+				}
+			}
+		}
+		nargs = append(nargs, narg)
+	}
+	return nargs
+}
+
+func (w *OmitWrapper) Log(fn LogFunc) LogFunc {
+	return func(ctx context.Context, level Level, args ...interface{}) {
+		fn(ctx, level, getArgs(args)...)
+	}
+}
+
+func (w *OmitWrapper) Logf(fn LogfFunc) LogfFunc {
+	return func(ctx context.Context, level Level, msg string, args ...interface{}) {
+		fn(ctx, level, msg, getArgs(args)...)
+	}
+}

util/fn/fn.go

@@ -0,0 +1,15 @@
+package fn
+
+type Initer interface {
+	Init(opts ...interface{}) error
+}
+
+func Init(ifaces ...Initer) error {
+	var err error
+	for _, iface := range ifaces {
+		if err = iface.Init(); err != nil {
+			return err
+		}
+	}
+	return nil
+}