Merge pull request 'allow to expose some method via http.HandlerFunc' (#158) from httphandler into master

Reviewed-on: #158

.github/workflows/build.yml

@@ -34,7 +34,7 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
       - name: lint
-        uses: golangci/golangci-lint-action@v3.3.1
+        uses: golangci/golangci-lint-action@v3.4.0
         continue-on-error: true
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.

.github/workflows/dependabot-automerge.yml

@@ -15,7 +15,7 @@ jobs:
     steps:
       - name: metadata
         id: metadata
-        uses: dependabot/fetch-metadata@v1.3.5
+        uses: dependabot/fetch-metadata@v1.3.6
         with:
           github-token: "${{ secrets.TOKEN }}"
       - name: merge

.github/workflows/pr.yml

@@ -34,7 +34,7 @@ jobs:
       - name: checkout
         uses: actions/checkout@v3
       - name: lint
-        uses: golangci/golangci-lint-action@v3.3.1
+        uses: golangci/golangci-lint-action@v3.4.0
         continue-on-error: true
         with:
           # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.

README.md

@@ -9,8 +9,8 @@ to create a HTTP Server that could potentially be used for REST based API servic
 import (
 	"net/http"
 
-	"github.com/unistack-org/micro/v3/server"
-	httpServer "github.com/unistack-org/micro-server-http"
+	"go.unistack.org/micro/v4/server"
+	httpServer "go.unistack.org/micro-server-http/v4"
 )
 
 func main() {
@@ -37,9 +37,9 @@ Or as part of a service
 import (
 	"net/http"
 
-	"github.com/unistack-org/micro/v3"
-	"github.com/unistack-org/micro/v3/server"
-	httpServer "github.com/unistack-org/micro-server-http"
+	"go.unistack.org/micro/v4"
+	"go.unistack.org/micro/v4/server"
+	httpServer "go.unistack.org/micro-server-http/v4"
 )
 
 func main() {

go.mod

@@ -1,9 +1,16 @@
-module go.unistack.org/micro-server-http/v3
+module go.unistack.org/micro-server-http/v4
 
-go 1.16
+go 1.19
 
 require (
-	go.unistack.org/micro/v3 v3.10.4
-	golang.org/x/net v0.0.0-20220624214902-1bab6f366d9e
+	go.unistack.org/micro-proto/v4 v4.0.0
+	go.unistack.org/micro/v4 v4.0.1
+	golang.org/x/net v0.7.0
+)
+
+require (
+	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/gnostic v0.6.9 // indirect
+	google.golang.org/protobuf v1.28.1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -10,7 +10,6 @@ github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDk
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
 github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
 github.com/cncf/xds/go v0.0.0-20210312221358-fbca930ec8ed/go.mod h1:eXthEFrGJvWHgFFCl3hGmgk+/aYT6PnTQLykKQRLhEs=
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=
@@ -45,24 +44,18 @@ github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/google/go-cmp v0.5.5 h1:Khx7svrCpmxxtHBq5j2mp/xVjsi8hQMfNLvJFAlrGgU=
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
-github.com/google/go-cmp v0.5.7 h1:81/ik6ipDQS2aGcBfIN5dHDB36BwrStyeAQquSYCV4o=
-github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
 github.com/google/uuid v1.1.2/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/grpc-ecosystem/grpc-gateway v1.16.0/go.mod h1:BDjrQk3hbvj6Nolgz8mAMFbcEtjT1g+wF4CSlocrBnw=
-github.com/imdario/mergo v0.3.13/go.mod h1:4lJ1jqUDcsbIECGy0RUJAXNIhg+6ocWgb1ALK2O4oXg=
+github.com/kr/pretty v0.2.0 h1:s5hAObm+yFO5uHYt5dYjxi2rXrsnmRpJx4OYvIWUaQs=
 github.com/kr/pretty v0.2.0/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
-github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
-github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
-github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
-github.com/silas/dag v0.0.0-20211117232152-9d50aa809f35/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/stoewer/go-strcase v1.2.0/go.mod h1:IBiWB2sKIp3wVVQ3Y035++gc+knqhUQag1KpM8ahLw8=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
@@ -72,10 +65,10 @@ github.com/xeipuuv/gojsonpointer v0.0.0-20180127040702-4e3ac2762d5f/go.mod h1:N2
 github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415/go.mod h1:GwrjFmJcFw6At/Gs6z4yjiIwzuJ1/+UwLxMQDVQXShQ=
 github.com/xeipuuv/gojsonschema v1.2.0/go.mod h1:anYRn/JVcOK2ZgGU+IjEV4nwlhoK5sQluxsYJ78Id3Y=
 go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqeYNgFYFoEGnI=
-go.unistack.org/micro-proto/v3 v3.3.1 h1:nQ0MtWvP2G3QrpOgawVOPhpZZYkq6umTGDqs8FxJYIo=
-go.unistack.org/micro-proto/v3 v3.3.1/go.mod h1:cwRyv8uInM2I7EbU7O8Fx2Ls3N90Uw9UCCcq4olOdfE=
-go.unistack.org/micro/v3 v3.10.4 h1:8HneC2t7oteTwwkFLmSg5bs62h/OqEzevx/IbXG1vRo=
-go.unistack.org/micro/v3 v3.10.4/go.mod h1:gI4RkJKHLPW7KV6h4+ZBOZD997MRvFRXMPQIHpozikI=
+go.unistack.org/micro-proto/v4 v4.0.0 h1:+TAwKSlx48eLsNO2E2cO0JLE8we1KU2AuWe9Q310FuU=
+go.unistack.org/micro-proto/v4 v4.0.0/go.mod h1:ArmK7o+uFvxSY3dbJhKBBX4Pm1rhWdLEFf3LxBrMtec=
+go.unistack.org/micro/v4 v4.0.1 h1:xo1IxbVfgh8i0eY0VeYa3cbb13u5n/Mxnp3FOgWD4Jo=
+go.unistack.org/micro/v4 v4.0.1/go.mod h1:p/J5UcSJjfHsWGT31uKoghQ5rUQZzQJBAFy+Z4+ZVMs=
 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=
@@ -91,8 +84,8 @@ golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn
 golang.org/x/net v0.0.0-20200822124328-c89045814202/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
 golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4/go.mod h1:p54w0d4576C0XHj96bSt6lcn1PtDYWL6XObtHCRCNQM=
 golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
-golang.org/x/net v0.0.0-20220624214902-1bab6f366d9e h1:TsQ7F31D3bUCLeqPT0u+yjp1guoArKaNKmCr22PYgTQ=
-golang.org/x/net v0.0.0-20220624214902-1bab6f366d9e/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
+golang.org/x/net v0.7.0 h1:rJrUqqhjsgNp7KqAIc25s9pZnjU7TUcSY7HcVZjdn1g=
+golang.org/x/net v0.7.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d/go.mod h1:gOpvHmFTYa4IltrdGE7lF6nIHvwfUNPOp7c8zoXwtLw=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -107,15 +100,11 @@ golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
-golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.5/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190226205152-f727befe758c/go.mod h1:9Yl7xja0Znq3iFh3HoIrodX9oNMXvdceNzlUR8zjMvY=
@@ -158,8 +147,6 @@ gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.3/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-gopkg.in/yaml.v3 v3.0.0/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=

handler.go

@@ -9,13 +9,13 @@ import (
 	"strings"
 	"sync"
 
-	"go.unistack.org/micro/v3/errors"
-	"go.unistack.org/micro/v3/logger"
-	"go.unistack.org/micro/v3/metadata"
-	"go.unistack.org/micro/v3/register"
-	"go.unistack.org/micro/v3/server"
-	rhttp "go.unistack.org/micro/v3/util/http"
-	rflutil "go.unistack.org/micro/v3/util/reflect"
+	"go.unistack.org/micro/v4/errors"
+	"go.unistack.org/micro/v4/logger"
+	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v4/register"
+	"go.unistack.org/micro/v4/server"
+	rhttp "go.unistack.org/micro/v4/util/http"
+	rflutil "go.unistack.org/micro/v4/util/reflect"
 )
 
 var (
@@ -60,6 +60,279 @@ func (h *httpHandler) Options() server.HandlerOptions {
 	return h.opts
 }
 
+func (h *httpServer) HTTPHandlerFunc(handler interface{}) (http.HandlerFunc, error) {
+	if handler == nil {
+		return nil, fmt.Errorf("invalid handler specified: %v", handler)
+	}
+
+	rtype := reflect.TypeOf(handler)
+	if rtype.NumIn() != 3 {
+		return nil, fmt.Errorf("invalid handler, NumIn != 3: %v", rtype.NumIn())
+	}
+
+	argType := rtype.In(1)
+	replyType := rtype.In(2)
+
+	// First arg need not be a pointer.
+	if !isExportedOrBuiltinType(argType) {
+		return nil, fmt.Errorf("invalid handler, argument type not exported: %v", argType)
+	}
+
+	if replyType.Kind() != reflect.Ptr {
+		return nil, fmt.Errorf("invalid handler, reply type not a pointer: %v", replyType)
+	}
+
+	// Reply type must be exported.
+	if !isExportedOrBuiltinType(replyType) {
+		return nil, fmt.Errorf("invalid handler, reply type not exported: %v", replyType)
+	}
+
+	if rtype.NumOut() != 1 {
+		return nil, fmt.Errorf("invalid handler, has wrong number of outs: %v", rtype.NumOut())
+	}
+
+	// The return type of the method must be error.
+	if returnType := rtype.Out(0); returnType != typeOfError {
+		return nil, fmt.Errorf("invalid handler, returns %v not error", returnType.String())
+	}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		ct := DefaultContentType
+		if htype := r.Header.Get(metadata.HeaderContentType); htype != "" {
+			ct = htype
+		}
+
+		ctx := context.WithValue(r.Context(), rspCodeKey{}, &rspCodeVal{})
+		ctx = context.WithValue(ctx, rspHeaderKey{}, &rspHeaderVal{})
+		md, ok := metadata.FromIncomingContext(ctx)
+		if !ok {
+			md = metadata.New(len(r.Header) + 8)
+		}
+		for k, v := range r.Header {
+			md[k] = strings.Join(v, ", ")
+		}
+		md["RemoteAddr"] = r.RemoteAddr
+		md["Method"] = r.Method
+		md["URL"] = r.URL.String()
+		md["Proto"] = r.Proto
+		md["ContentLength"] = fmt.Sprintf("%d", r.ContentLength)
+		md["TransferEncoding"] = strings.Join(r.TransferEncoding, ",")
+		md["Host"] = r.Host
+		md["RequestURI"] = r.RequestURI
+		ctx = metadata.NewIncomingContext(ctx, md)
+
+		path := r.URL.Path
+
+		if r.Body != nil {
+			defer r.Body.Close()
+		}
+
+		matches := make(map[string]interface{})
+		var match bool
+		var hldr *patHandler
+		var handler *httpHandler
+
+		for _, shdlr := range h.handlers {
+			hdlr := shdlr.(*httpHandler)
+			fh, mp, err := hdlr.handlers.Search(r.Method, path)
+			if err == nil {
+				match = true
+				for k, v := range mp {
+					matches[k] = v
+				}
+				hldr = fh.(*patHandler)
+				handler = hdlr
+				break
+			} else if err == rhttp.ErrMethodNotAllowed && !h.registerRPC {
+				w.WriteHeader(http.StatusMethodNotAllowed)
+				_, _ = w.Write([]byte("not matching route found"))
+				return
+			}
+		}
+
+		if !match && h.registerRPC {
+			microMethod, mok := md.Get(metadata.HeaderEndpoint)
+			if mok {
+				serviceMethod := strings.Split(microMethod, ".")
+				if len(serviceMethod) == 2 {
+					if shdlr, ok := h.handlers[serviceMethod[0]]; ok {
+						hdlr := shdlr.(*httpHandler)
+						fh, mp, err := hdlr.handlers.Search(http.MethodPost, "/"+microMethod)
+						if err == nil {
+							match = true
+							for k, v := range mp {
+								matches[k] = v
+							}
+							hldr = fh.(*patHandler)
+							handler = hdlr
+						}
+					}
+				}
+			}
+		}
+
+		// get fields from url values
+		if len(r.URL.RawQuery) > 0 {
+			umd, cerr := rflutil.URLMap(r.URL.RawQuery)
+			if cerr != nil {
+				w.WriteHeader(http.StatusInternalServerError)
+				_, _ = w.Write([]byte(cerr.Error()))
+				return
+			}
+			for k, v := range umd {
+				matches[k] = v
+			}
+		}
+
+		cf, err := h.newCodec(ct)
+		if err != nil {
+			w.WriteHeader(http.StatusBadRequest)
+			_, _ = w.Write([]byte(err.Error()))
+			return
+		}
+
+		var argv, replyv reflect.Value
+
+		// Decode the argument value.
+		argIsValue := false // if true, need to indirect before calling.
+		if hldr.mtype.ArgType.Kind() == reflect.Ptr {
+			argv = reflect.New(hldr.mtype.ArgType.Elem())
+		} else {
+			argv = reflect.New(hldr.mtype.ArgType)
+			argIsValue = true
+		}
+
+		if argIsValue {
+			argv = argv.Elem()
+		}
+
+		// reply value
+		replyv = reflect.New(hldr.mtype.ReplyType.Elem())
+
+		function := hldr.mtype.method.Func
+		var returnValues []reflect.Value
+
+		if r.Body != nil {
+			var buf []byte
+			buf, err = io.ReadAll(r.Body)
+			if err != nil && err != io.EOF {
+				h.errorHandler(ctx, handler, w, r, err, http.StatusInternalServerError)
+				return
+			}
+
+			if err = cf.Unmarshal(buf, argv.Interface()); err != nil {
+				h.errorHandler(ctx, handler, w, r, err, http.StatusBadRequest)
+				return
+			}
+		}
+
+		matches = rflutil.FlattenMap(matches)
+		if err = rflutil.Merge(argv.Interface(), matches, rflutil.SliceAppend(true), rflutil.Tags([]string{"protobuf", "json"})); err != nil {
+			h.errorHandler(ctx, handler, w, r, err, http.StatusBadRequest)
+			return
+		}
+
+		hr := &rpcRequest{
+			codec:       cf,
+			service:     handler.sopts.Name,
+			contentType: ct,
+			method:      fmt.Sprintf("%s.%s", hldr.name, hldr.mtype.method.Name),
+			endpoint:    fmt.Sprintf("%s.%s", hldr.name, hldr.mtype.method.Name),
+			payload:     argv.Interface(),
+			header:      md,
+		}
+
+		// define the handler func
+		fn := func(fctx context.Context, req server.Request, rsp interface{}) (err error) {
+			returnValues = function.Call([]reflect.Value{hldr.rcvr, hldr.mtype.prepareContext(fctx), argv, reflect.ValueOf(rsp)})
+
+			// The return value for the method is an error.
+			if rerr := returnValues[0].Interface(); rerr != nil {
+				err = rerr.(error)
+			}
+
+			md, ok := metadata.FromOutgoingContext(ctx)
+			if !ok {
+				md = metadata.New(0)
+			}
+			if nmd, ok := metadata.FromOutgoingContext(fctx); ok {
+				for k, v := range nmd {
+					md.Set(k, v)
+				}
+			}
+			metadata.SetOutgoingContext(ctx, md)
+
+			return err
+		}
+
+		// wrap the handler func
+		for i := len(handler.sopts.HdlrWrappers); i > 0; i-- {
+			fn = handler.sopts.HdlrWrappers[i-1](fn)
+		}
+
+		if ct == "application/x-www-form-urlencoded" {
+			cf, err = h.newCodec(DefaultContentType)
+			if err != nil {
+				h.errorHandler(ctx, handler, w, r, err, http.StatusInternalServerError)
+				return
+			}
+			ct = DefaultContentType
+		}
+
+		scode := int(200)
+		appErr := fn(ctx, hr, replyv.Interface())
+
+		w.Header().Set(metadata.HeaderContentType, ct)
+		if md, ok := metadata.FromOutgoingContext(ctx); ok {
+			for k, v := range md {
+				w.Header().Set(k, v)
+			}
+		}
+		if md := getRspHeader(ctx); md != nil {
+			for k, v := range md {
+				for _, vv := range v {
+					w.Header().Add(k, vv)
+				}
+			}
+		}
+		if nct := w.Header().Get(metadata.HeaderContentType); nct != ct {
+			if cf, err = h.newCodec(nct); err != nil {
+				h.errorHandler(ctx, nil, w, r, err, http.StatusBadRequest)
+				return
+			}
+		}
+
+		var buf []byte
+		if appErr != nil {
+			switch verr := appErr.(type) {
+			case *errors.Error:
+				scode = int(verr.Code)
+				buf, err = cf.Marshal(verr)
+			case *Error:
+				buf, err = cf.Marshal(verr.err)
+			default:
+				buf, err = cf.Marshal(appErr)
+			}
+		} else {
+			buf, err = cf.Marshal(replyv.Interface())
+		}
+
+		if err != nil && handler.sopts.Logger.V(logger.ErrorLevel) {
+			handler.sopts.Logger.Errorf(handler.sopts.Context, "handler err: %v", err)
+			return
+		}
+
+		if nscode := GetRspCode(ctx); nscode != 0 {
+			scode = nscode
+		}
+		w.WriteHeader(scode)
+
+		if _, cerr := w.Write(buf); cerr != nil {
+			handler.sopts.Logger.Errorf(ctx, "write failed: %v", cerr)
+		}
+	}, nil
+}
+
 func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// check for http.HandlerFunc handlers
 	if ph, _, err := h.pathHandlers.Search(r.Method, r.URL.Path); err == nil {
@@ -73,24 +346,27 @@ func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 
 	ctx := context.WithValue(r.Context(), rspCodeKey{}, &rspCodeVal{})
+	ctx = context.WithValue(ctx, rspHeaderKey{}, &rspHeaderVal{})
 	md, ok := metadata.FromIncomingContext(ctx)
 	if !ok {
 		md = metadata.New(len(r.Header) + 8)
 	}
 	for k, v := range r.Header {
-		md.Set(k, strings.Join(v, ", "))
+		md[k] = strings.Join(v, ", ")
 	}
-	md.Set("RemoteAddr", r.RemoteAddr)
-	md.Set("Method", r.Method)
-	md.Set("URL", r.URL.String())
-	md.Set("Proto", r.Proto)
-	md.Set("ContentLength", fmt.Sprintf("%d", r.ContentLength))
-	md.Set("TransferEncoding", strings.Join(r.TransferEncoding, ","))
-	md.Set("Host", r.Host)
-	md.Set("RequestURI", r.RequestURI)
+	md["RemoteAddr"] = r.RemoteAddr
+	md["Method"] = r.Method
+	md["URL"] = r.URL.String()
+	md["Proto"] = r.Proto
+	md["ContentLength"] = fmt.Sprintf("%d", r.ContentLength)
+	md["TransferEncoding"] = strings.Join(r.TransferEncoding, ",")
+	md["Host"] = r.Host
+	md["RequestURI"] = r.RequestURI
 	ctx = metadata.NewIncomingContext(ctx, md)
 
-	defer r.Body.Close()
+	if r.Body != nil {
+		defer r.Body.Close()
+	}
 
 	path := r.URL.Path
 	if !strings.HasPrefix(path, "/") {
@@ -116,7 +392,8 @@ func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			handler = hdlr
 			break
 		} else if err == rhttp.ErrMethodNotAllowed && !h.registerRPC {
-			h.errorHandler(ctx, nil, w, r, fmt.Errorf("not matching route found"), http.StatusNotFound)
+			h.errorHandler(ctx, nil, w, r, fmt.Errorf("not matching route found"), http.StatusMethodNotAllowed)
+			return
 		}
 	}
 
@@ -190,15 +467,18 @@ func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	function := hldr.mtype.method.Func
 	var returnValues []reflect.Value
 
-	buf, err := io.ReadAll(r.Body)
-	if err != nil && err != io.EOF {
-		h.errorHandler(ctx, handler, w, r, err, http.StatusInternalServerError)
-		return
-	}
+	if r.Body != nil {
+		var buf []byte
+		buf, err = io.ReadAll(r.Body)
+		if err != nil && err != io.EOF {
+			h.errorHandler(ctx, handler, w, r, err, http.StatusInternalServerError)
+			return
+		}
 
-	if err = cf.Unmarshal(buf, argv.Interface()); err != nil {
-		h.errorHandler(ctx, handler, w, r, err, http.StatusBadRequest)
-		return
+		if err = cf.Unmarshal(buf, argv.Interface()); err != nil {
+			h.errorHandler(ctx, handler, w, r, err, http.StatusBadRequest)
+			return
+		}
 	}
 
 	matches = rflutil.FlattenMap(matches)
@@ -263,6 +543,13 @@ func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			w.Header().Set(k, v)
 		}
 	}
+	if md := getRspHeader(ctx); md != nil {
+		for k, v := range md {
+			for _, vv := range v {
+				w.Header().Add(k, vv)
+			}
+		}
+	}
 	if nct := w.Header().Get(metadata.HeaderContentType); nct != ct {
 		if cf, err = h.newCodec(nct); err != nil {
 			h.errorHandler(ctx, nil, w, r, err, http.StatusBadRequest)
@@ -270,6 +557,7 @@ func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	var buf []byte
 	if appErr != nil {
 		switch verr := appErr.(type) {
 		case *errors.Error:

handler/generate.go

@@ -0,0 +1,12 @@
+package handler
+
+import (
+	// import required packages
+	_ "go.unistack.org/micro-proto/v4/openapiv3"
+)
+
+//go:generate sh -c "curl -L https://github.com/swagger-api/swagger-ui/archive/refs/tags/v4.18.3.zip -o - | bsdtar -C swagger-ui --strip-components=2 -xv swagger-ui-4.18.3/dist && rm swagger-ui/*.map swagger-ui/*-es-*.js swagger-ui/swagger-ui.js swagger-ui/swagger-initializer.js"
+
+//go:generate sh -c "protoc -I./ -I$(go list -f '{{ .Dir }}' -m go.unistack.org/micro-proto/v4) --go-micro_out='components=micro|http|server',standalone=false,debug=true,paths=source_relative:./ ./meter/meter.proto"
+
+//go:generate sh -c "protoc -I./ -I$(go list -f '{{ .Dir }}' -m go.unistack.org/micro-proto/v4) --go-micro_out='components=micro|http|server',standalone=false,debug=true,paths=source_relative:./ ./health/health.proto"

handler/health/health.go

@@ -0,0 +1,82 @@
+package health // import "go.unistack.org/micro-server-http/v4/handler/health"
+
+import (
+	"context"
+
+	codecpb "go.unistack.org/micro-proto/v4/codec"
+	"go.unistack.org/micro/v4/errors"
+)
+
+var _ HealthServiceServer = (*Handler)(nil)
+
+type Handler struct {
+	opts Options
+}
+
+type CheckFunc func(context.Context) error
+
+type Option func(*Options)
+
+type Options struct {
+	Version     string
+	Name        string
+	LiveChecks  []CheckFunc
+	ReadyChecks []CheckFunc
+}
+
+func LiveChecks(fns ...CheckFunc) Option {
+	return func(o *Options) {
+		o.LiveChecks = append(o.LiveChecks, fns...)
+	}
+}
+
+func ReadyChecks(fns ...CheckFunc) Option {
+	return func(o *Options) {
+		o.ReadyChecks = append(o.ReadyChecks, fns...)
+	}
+}
+
+func Name(name string) Option {
+	return func(o *Options) {
+		o.Name = name
+	}
+}
+
+func Version(version string) Option {
+	return func(o *Options) {
+		o.Version = version
+	}
+}
+
+func NewHandler(opts ...Option) *Handler {
+	options := Options{}
+	for _, o := range opts {
+		o(&options)
+	}
+	return &Handler{opts: options}
+}
+
+func (h *Handler) Live(ctx context.Context, req *codecpb.Frame, rsp *codecpb.Frame) error {
+	var err error
+	for _, fn := range h.opts.LiveChecks {
+		if err = fn(ctx); err != nil {
+			return errors.ServiceUnavailable(h.opts.Name, "%v", err)
+		}
+	}
+	return nil
+}
+
+func (h *Handler) Ready(ctx context.Context, req *codecpb.Frame, rsp *codecpb.Frame) error {
+	var err error
+	for _, fn := range h.opts.ReadyChecks {
+		if err = fn(ctx); err != nil {
+			return errors.ServiceUnavailable(h.opts.Name, "%v", err)
+		}
+	}
+	return nil
+}
+
+func (h *Handler) Version(ctx context.Context, req *codecpb.Frame, rsp *codecpb.Frame) error {
+	rsp.Data = []byte(h.opts.Version)
+	return nil
+}

handler/health/health.proto

@@ -0,0 +1,50 @@
+syntax = "proto3";
+
+package micro.server.http.v4.handler.health;
+option go_package = "go.unistack.org/micro-server-http/v4/handler/health;health";
+
+import "api/annotations.proto";
+import "openapiv3/annotations.proto";
+import "codec/frame.proto";
+
+service HealthService {
+	rpc Live(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv3.openapiv3_operation) = {
+      operation_id: "Live";
+      responses: {
+        default: {
+          reference: {
+            _ref: "micro.codec.Frame";
+          };
+        };
+      };
+    };
+		option (micro.api.http) = { get: "/live"; };
+  };
+	rpc Ready(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv3.openapiv3_operation) = {
+      operation_id: "Ready";
+      responses: {
+        default: {
+          reference: {
+            _ref: "micro.codec.Frame";
+          };
+        };
+      };
+    };
+		option (micro.api.http) = { get: "/ready"; };
+  };
+	rpc Version(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv3.openapiv3_operation) = {
+      operation_id: "Version";
+      responses: {
+        default: {
+          reference: {
+            _ref: "micro.codec.Frame";
+          };
+        };
+      };
+    };
+		option (micro.api.http) = { get: "/version"; };
+  };
+};

handler/health/health_micro.pb.go

@@ -0,0 +1,48 @@
+// Code generated by protoc-gen-go-micro. DO NOT EDIT.
+// versions:
+// - protoc-gen-go-micro v4.0.0
+// - protoc              v3.21.12
+// source: health/health.proto
+
+package health
+
+import (
+	context "context"
+	codec "go.unistack.org/micro-proto/v4/codec"
+	v4 "go.unistack.org/micro-server-http/v4"
+)
+
+var (
+	HealthServiceName = "HealthService"
+)
+var (
+	HealthServiceServerEndpoints = []v4.EndpointMetadata{
+		{
+			Name:   "HealthService.Live",
+			Path:   "/live",
+			Method: "GET",
+			Body:   "",
+			Stream: false,
+		},
+		{
+			Name:   "HealthService.Ready",
+			Path:   "/ready",
+			Method: "GET",
+			Body:   "",
+			Stream: false,
+		},
+		{
+			Name:   "HealthService.Version",
+			Path:   "/version",
+			Method: "GET",
+			Body:   "",
+			Stream: false,
+		},
+	}
+)
+
+type HealthServiceServer interface {
+	Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+}

handler/health/health_micro_http.pb.go

@@ -0,0 +1,43 @@
+// Code generated by protoc-gen-go-micro. DO NOT EDIT.
+// protoc-gen-go-micro version: v4.0.0
+// source: health/health.proto
+
+package health
+
+import (
+	context "context"
+	codec "go.unistack.org/micro-proto/v4/codec"
+	v4 "go.unistack.org/micro-server-http/v4"
+	server "go.unistack.org/micro/v4/server"
+)
+
+type healthServiceServer struct {
+	HealthServiceServer
+}
+
+func (h *healthServiceServer) Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServiceServer.Live(ctx, req, rsp)
+}
+
+func (h *healthServiceServer) Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServiceServer.Ready(ctx, req, rsp)
+}
+
+func (h *healthServiceServer) Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.HealthServiceServer.Version(ctx, req, rsp)
+}
+
+func RegisterHealthServiceServer(s server.Server, sh HealthServiceServer, opts ...server.HandlerOption) error {
+	type healthService interface {
+		Live(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+		Ready(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+		Version(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	}
+	type HealthService struct {
+		healthService
+	}
+	h := &healthServiceServer{sh}
+	var nopts []server.HandlerOption
+	nopts = append(nopts, v4.HandlerEndpoints(HealthServiceServerEndpoints))
+	return s.Handle(s.NewHandler(&HealthService{h}, append(nopts, opts...)...))
+}

handler/meter/meter.go

@@ -0,0 +1,67 @@
+package meter // import "go.unistack.org/micro-server-http/v4/handler/meter"
+
+import (
+	"bytes"
+	"context"
+
+	codecpb "go.unistack.org/micro-proto/v4/codec"
+	"go.unistack.org/micro/v4/errors"
+	"go.unistack.org/micro/v4/meter"
+)
+
+// guard to fail early
+var _ MeterServiceServer = (*Handler)(nil)
+
+type Handler struct {
+	opts Options
+}
+
+type Option func(*Options)
+
+type Options struct {
+	Meter        meter.Meter
+	Name         string
+	MeterOptions []meter.Option
+}
+
+func Meter(m meter.Meter) Option {
+	return func(o *Options) {
+		o.Meter = m
+	}
+}
+
+func Name(name string) Option {
+	return func(o *Options) {
+		o.Name = name
+	}
+}
+
+func MeterOptions(opts ...meter.Option) Option {
+	return func(o *Options) {
+		o.MeterOptions = append(o.MeterOptions, opts...)
+	}
+}
+
+func NewOptions(opts ...Option) Options {
+	options := Options{Meter: meter.DefaultMeter}
+	for _, o := range opts {
+		o(&options)
+	}
+	return options
+}
+
+func NewHandler(opts ...Option) *Handler {
+	options := NewOptions(opts...)
+	return &Handler{opts: options}
+}
+
+func (h *Handler) Metrics(ctx context.Context, req *codecpb.Frame, rsp *codecpb.Frame) error {
+	buf := bytes.NewBuffer(nil)
+	if err := h.opts.Meter.Write(buf, h.opts.MeterOptions...); err != nil {
+		return errors.InternalServerError(h.opts.Name, "%v", err)
+	}
+
+	rsp.Data = buf.Bytes()
+
+	return nil
+}

handler/meter/meter.proto

@@ -0,0 +1,24 @@
+syntax = "proto3";
+
+package micro.server.http.v4.handler.meter;
+option go_package = "go.unistack.org/micro-server-http/v4/handler/meter;meter";
+
+import "api/annotations.proto";
+import "openapiv3/annotations.proto";
+import "codec/frame.proto";
+
+service MeterService {
+	rpc Metrics(micro.codec.Frame) returns (micro.codec.Frame) {
+		option (micro.openapiv3.openapiv3_operation) = {
+      operation_id: "Metrics";
+      responses: {
+        default: {
+          reference: {
+            _ref: "micro.codec.Frame";
+          };
+        };
+      };
+    };
+		option (micro.api.http) = { get: "/metrics"; };
+  };
+};

handler/meter/meter_micro.pb.go

@@ -0,0 +1,32 @@
+// Code generated by protoc-gen-go-micro. DO NOT EDIT.
+// versions:
+// - protoc-gen-go-micro v4.0.0
+// - protoc              v3.21.12
+// source: meter/meter.proto
+
+package meter
+
+import (
+	context "context"
+	codec "go.unistack.org/micro-proto/v4/codec"
+	v4 "go.unistack.org/micro-server-http/v4"
+)
+
+var (
+	MeterServiceName = "MeterService"
+)
+var (
+	MeterServiceServerEndpoints = []v4.EndpointMetadata{
+		{
+			Name:   "MeterService.Metrics",
+			Path:   "/metrics",
+			Method: "GET",
+			Body:   "",
+			Stream: false,
+		},
+	}
+)
+
+type MeterServiceServer interface {
+	Metrics(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+}

handler/meter/meter_micro_http.pb.go

@@ -0,0 +1,33 @@
+// Code generated by protoc-gen-go-micro. DO NOT EDIT.
+// protoc-gen-go-micro version: v4.0.0
+// source: meter/meter.proto
+
+package meter
+
+import (
+	context "context"
+	codec "go.unistack.org/micro-proto/v4/codec"
+	v4 "go.unistack.org/micro-server-http/v4"
+	server "go.unistack.org/micro/v4/server"
+)
+
+type meterServiceServer struct {
+	MeterServiceServer
+}
+
+func (h *meterServiceServer) Metrics(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error {
+	return h.MeterServiceServer.Metrics(ctx, req, rsp)
+}
+
+func RegisterMeterServiceServer(s server.Server, sh MeterServiceServer, opts ...server.HandlerOption) error {
+	type meterService interface {
+		Metrics(ctx context.Context, req *codec.Frame, rsp *codec.Frame) error
+	}
+	type MeterService struct {
+		meterService
+	}
+	h := &meterServiceServer{sh}
+	var nopts []server.HandlerOption
+	nopts = append(nopts, v4.HandlerEndpoints(MeterServiceServerEndpoints))
+	return s.Handle(s.NewHandler(&MeterService{h}, append(nopts, opts...)...))
+}

handler/swagger-ui/index.css

@@ -0,0 +1,16 @@
+html {
+    box-sizing: border-box;
+    overflow: -moz-scrollbars-vertical;
+    overflow-y: scroll;
+}
+
+*,
+*:before,
+*:after {
+    box-sizing: inherit;
+}
+
+body {
+    margin: 0;
+    background: #fafafa;
+}

handler/swagger-ui/index.html

@@ -0,0 +1,19 @@
+<!-- HTML for static distribution bundle build -->
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8">
+    <title>Swagger UI</title>
+    <link rel="stylesheet" type="text/css" href="./swagger-ui.css" />
+    <link rel="stylesheet" type="text/css" href="index.css" />
+    <link rel="icon" type="image/png" href="./favicon-32x32.png" sizes="32x32" />
+    <link rel="icon" type="image/png" href="./favicon-16x16.png" sizes="16x16" />
+  </head>
+
+  <body>
+    <div id="swagger-ui"></div>
+    <script src="./swagger-ui-bundle.js" charset="UTF-8"> </script>
+    <script src="./swagger-ui-standalone-preset.js" charset="UTF-8"> </script>
+    <script src="./swagger-initializer.js" charset="UTF-8"> </script>
+  </body>
+</html>

handler/swagger-ui/oauth2-redirect.html

@@ -0,0 +1,79 @@
+<!doctype html>
+<html lang="en-US">
+<head>
+    <title>Swagger UI: OAuth2 Redirect</title>
+</head>
+<body>
+<script>
+    'use strict';
+    function run () {
+        var oauth2 = window.opener.swaggerUIRedirectOauth2;
+        var sentState = oauth2.state;
+        var redirectUrl = oauth2.redirectUrl;
+        var isValid, qp, arr;
+
+        if (/code|token|error/.test(window.location.hash)) {
+            qp = window.location.hash.substring(1).replace('?', '&');
+        } else {
+            qp = location.search.substring(1);
+        }
+
+        arr = qp.split("&");
+        arr.forEach(function (v,i,_arr) { _arr[i] = '"' + v.replace('=', '":"') + '"';});
+        qp = qp ? JSON.parse('{' + arr.join() + '}',
+                function (key, value) {
+                    return key === "" ? value : decodeURIComponent(value);
+                }
+        ) : {};
+
+        isValid = qp.state === sentState;
+
+        if ((
+          oauth2.auth.schema.get("flow") === "accessCode" ||
+          oauth2.auth.schema.get("flow") === "authorizationCode" ||
+          oauth2.auth.schema.get("flow") === "authorization_code"
+        ) && !oauth2.auth.code) {
+            if (!isValid) {
+                oauth2.errCb({
+                    authId: oauth2.auth.name,
+                    source: "auth",
+                    level: "warning",
+                    message: "Authorization may be unsafe, passed state was changed in server. The passed state wasn't returned from auth server."
+                });
+            }
+
+            if (qp.code) {
+                delete oauth2.state;
+                oauth2.auth.code = qp.code;
+                oauth2.callback({auth: oauth2.auth, redirectUrl: redirectUrl});
+            } else {
+                let oauthErrorMsg;
+                if (qp.error) {
+                    oauthErrorMsg = "["+qp.error+"]: " +
+                        (qp.error_description ? qp.error_description+ ". " : "no accessCode received from the server. ") +
+                        (qp.error_uri ? "More info: "+qp.error_uri : "");
+                }
+
+                oauth2.errCb({
+                    authId: oauth2.auth.name,
+                    source: "auth",
+                    level: "error",
+                    message: oauthErrorMsg || "[Authorization failed]: no accessCode received from the server."
+                });
+            }
+        } else {
+            oauth2.callback({auth: oauth2.auth, token: qp, isValid: isValid, redirectUrl: redirectUrl});
+        }
+        window.close();
+    }
+
+    if (document.readyState !== 'loading') {
+        run();
+    } else {
+        document.addEventListener('DOMContentLoaded', function () {
+            run();
+        });
+    }
+</script>
+</body>
+</html>

handler/swagger-ui/swagger-initializer.js

@@ -0,0 +1,20 @@
+window.onload = function() {
+  //<editor-fold desc="Changeable Configuration Block">
+
+  // the following lines will be replaced by docker/configurator, when it runs in a docker-container
+  window.ui = SwaggerUIBundle({
+    url: "{{ .SWAGGER }}",
+    dom_id: '#swagger-ui',
+    deepLinking: true,
+    presets: [
+      SwaggerUIBundle.presets.apis,
+      SwaggerUIStandalonePreset
+    ],
+    plugins: [
+      SwaggerUIBundle.plugins.DownloadUrl
+    ],
+    layout: "StandaloneLayout"
+  });
+
+  //</editor-fold>
+};

handler/swagger-ui/swaggerui.go

@@ -0,0 +1,142 @@
+package swaggerui // import "go.unistack.org/micro-server-http/v4/handler/swagger-ui"
+
+import (
+	"embed"
+	"html/template"
+	"net/http"
+	"path"
+	"reflect"
+)
+
+//go:embed *.js *.css *.html *.png
+var assets embed.FS
+
+var (
+	Handler = func(prefix string) http.HandlerFunc {
+		return func(w http.ResponseWriter, r *http.Request) {
+			if r.Method != http.MethodGet || path.Base(r.URL.Path) != "swagger-initializer.js" {
+				http.StripPrefix(prefix, http.FileServer(http.FS(assets))).ServeHTTP(w, r)
+				return
+			}
+			tpl := template.New("swagger-initializer.js").Funcs(TemplateFuncs)
+			ptpl, err := tpl.Parse(Template)
+			if err != nil {
+				w.WriteHeader(http.StatusInternalServerError)
+				_, _ = w.Write([]byte(err.Error()))
+				return
+			}
+			if err := ptpl.Execute(w, Config); err != nil {
+				w.WriteHeader(http.StatusInternalServerError)
+				_, _ = w.Write([]byte(err.Error()))
+				return
+			}
+		}
+	}
+	TemplateFuncs = template.FuncMap{
+		"isInt": func(i interface{}) bool {
+			v := reflect.ValueOf(i)
+			switch v.Kind() {
+			case reflect.Int, reflect.Int8, reflect.Int32, reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64:
+				return true
+			default:
+				return false
+			}
+		},
+		"isBool": func(i interface{}) bool {
+			v := reflect.ValueOf(i)
+			switch v.Kind() {
+			case reflect.Bool:
+				return true
+			default:
+				return false
+			}
+		},
+		"isString": func(i interface{}) bool {
+			v := reflect.ValueOf(i)
+			switch v.Kind() {
+			case reflect.String:
+				return true
+			default:
+				return false
+			}
+		},
+		"isSlice": func(i interface{}) bool {
+			v := reflect.ValueOf(i)
+			switch v.Kind() {
+			case reflect.Slice:
+				return true
+			default:
+				return false
+			}
+		},
+		"isMap": func(i interface{}) bool {
+			v := reflect.ValueOf(i)
+			switch v.Kind() {
+			case reflect.Map:
+				return true
+			default:
+				return false
+			}
+		},
+	}
+	Template = `
+	window.onload = function() {
+		//<editor-fold desc="Changeable Configuration Block">
+	
+		window.ui = SwaggerUIBundle({
+			{{- range $k, $v := . }}
+			{{- if (eq (printf "%s" $v) "") -}}
+			{{- continue -}}
+			{{ end }}
+			{{ $k }}: {{ if isBool $v -}}
+			{{- $v -}},
+			{{- else if isInt $v -}}
+      {{- $v -}},
+			{{- else if isString $v -}}
+			"{{- $v -}}",
+			{{- else if and (isSlice $v) (or (eq (printf "%s" $k) "presets") (eq (printf "%s" $k) "plugins")) -}}
+			[
+			{{- range $v }}
+				{{ . }},
+			{{- end }}
+			],
+			{{- end -}} 
+			{{ end }}
+		});
+	
+		//</editor-fold>
+	};`
+	Config = map[string]interface{}{
+		"configUrl": "",
+		"dom_id":    "#swagger-ui",
+		/*
+				"domNode":     "",
+			  "spec":        "",
+				"urls": []interface{}{
+					map[string]interface{}{
+							"url":  "",
+							"name": "",
+						},
+					},
+				},
+		*/
+		"url":                      "https://petstore.swagger.io/v2/swagger.json",
+		"deepLinking":              true,
+		"displayOperationId":       false,
+		"defaultModelsExpandDepth": 1,
+		"defaultModelExpandDepth":  1,
+		"displayRequestDuration":   true,
+		"filter":                   true,
+		"operationsSorter":         "alpha",
+		"showExtensions":           true,
+		"tryItOutEnabled":          true,
+		"presets": []string{
+			"SwaggerUIBundle.presets.apis",
+			"SwaggerUIStandalonePreset",
+		},
+		"plugins": []string{
+			"SwaggerUIBundle.plugins.DownloadUrl",
+		},
+		"layout": "StandaloneLayout",
+	}
+)

handler/swagger-ui/swaggerui_test.go

@@ -0,0 +1,15 @@
+package swaggerui
+
+import (
+	"net/http"
+	"testing"
+)
+
+func TestTemplate(t *testing.T) {
+	t.Skip()
+	h := http.NewServeMux()
+	h.HandleFunc("/", Handler(""))
+	if err := http.ListenAndServe(":8080", h); err != nil {
+		t.Fatal(err)
+	}
+}

http.go

@@ -1,5 +1,5 @@
 // Package http implements a go-micro.Server
-package http // import "go.unistack.org/micro-server-http/v3"
+package http // import "go.unistack.org/micro-server-http/v4"
 
 import (
 	"context"
@@ -14,12 +14,12 @@ import (
 	"sync"
 	"time"
 
-	"go.unistack.org/micro/v3/broker"
-	"go.unistack.org/micro/v3/codec"
-	"go.unistack.org/micro/v3/logger"
-	"go.unistack.org/micro/v3/register"
-	"go.unistack.org/micro/v3/server"
-	rhttp "go.unistack.org/micro/v3/util/http"
+	"go.unistack.org/micro/v4/broker"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/logger"
+	"go.unistack.org/micro/v4/register"
+	"go.unistack.org/micro/v4/server"
+	rhttp "go.unistack.org/micro/v4/util/http"
 	"golang.org/x/net/netutil"
 )
 
@@ -235,6 +235,56 @@ func (h *httpServer) NewHandler(handler interface{}, opts ...server.HandlerOptio
 		}
 	}
 
+	metadata, ok := options.Context.Value(handlerEndpointsKey{}).([]EndpointMetadata)
+	if !ok {
+		return hdlr
+	}
+
+	for _, md := range metadata {
+		hn := md.Name
+		var method reflect.Method
+		mname := hn[strings.Index(hn, ".")+1:]
+		for m := 0; m < tp.NumMethod(); m++ {
+			mn := tp.Method(m)
+			if mn.Name != mname {
+				continue
+			}
+			method = mn
+			break
+		}
+
+		if method.Name == "" && h.opts.Logger.V(logger.ErrorLevel) {
+			h.opts.Logger.Errorf(h.opts.Context, "nil method for %s", mname)
+			continue
+		}
+
+		mtype, err := prepareEndpoint(method)
+		if err != nil && h.opts.Logger.V(logger.ErrorLevel) {
+			h.opts.Logger.Errorf(h.opts.Context, "%v", err)
+			continue
+		} else if mtype == nil {
+			h.opts.Logger.Errorf(h.opts.Context, "nil mtype for %s", mname)
+			continue
+		}
+
+		rcvr := reflect.ValueOf(handler)
+		name := reflect.Indirect(rcvr).Type().Name()
+
+		pth := &patHandler{mtype: mtype, name: name, rcvr: rcvr}
+		hdlr.name = name
+
+		if err := hdlr.handlers.Insert([]string{md.Method}, md.Path, pth); err != nil {
+			h.opts.Logger.Errorf(h.opts.Context, "cant add handler for %s %s", md.Method, md.Path)
+		}
+
+		if h.registerRPC {
+			h.opts.Logger.Infof(h.opts.Context, "register rpc handler for http.MethodPost %s /%s", hn, hn)
+			if err := hdlr.handlers.Insert([]string{http.MethodPost}, "/"+hn, pth); err != nil {
+				h.opts.Logger.Errorf(h.opts.Context, "cant add rpc handler for http.MethodPost %s /%s", hn, hn)
+			}
+		}
+	}
+
 	return hdlr
 }
 

message.go

@@ -1,8 +1,8 @@
 package http
 
 import (
-	"go.unistack.org/micro/v3/codec"
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/metadata"
 )
 
 type httpMessage struct {

options.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"net/http"
 
-	"go.unistack.org/micro/v3/server"
+	"go.unistack.org/micro/v4/server"
 )
 
 // SetError pass error to caller
@@ -38,6 +38,20 @@ type (
 	}
 )
 
+type (
+	rspHeaderKey struct{}
+	rspHeaderVal struct {
+		h http.Header
+	}
+)
+
+// SetRspHeader add response headers
+func SetRspHeader(ctx context.Context, h http.Header) {
+	if rsp, ok := ctx.Value(rspHeaderKey{}).(*rspHeaderVal); ok {
+		rsp.h = h
+	}
+}
+
 // SetRspCode saves response code in context, must be used by handler to specify http code
 func SetRspCode(ctx context.Context, code int) {
 	if rsp, ok := ctx.Value(rspCodeKey{}).(*rspCodeVal); ok {
@@ -45,6 +59,14 @@ func SetRspCode(ctx context.Context, code int) {
 	}
 }
 
+// getRspHeader get http.Header from context
+func getRspHeader(ctx context.Context) http.Header {
+	if rsp, ok := ctx.Value(rspHeaderKey{}).(*rspHeaderVal); ok {
+		return rsp.h
+	}
+	return nil
+}
+
 // GetRspCode used internally by generated http server handler
 func GetRspCode(ctx context.Context) int {
 	var code int
@@ -111,7 +133,19 @@ func RegisterRPCHandler(b bool) server.Option {
 	return server.SetOption(registerRPCHandlerKey{}, b)
 }
 
-type headerKey struct{}
+type handlerEndpointsKey struct{}
+
+type EndpointMetadata struct {
+	Name   string
+	Path   string
+	Method string
+	Body   string
+	Stream bool
+}
+
+func HandlerEndpoints(md []EndpointMetadata) server.HandlerOption {
+	return server.SetHandlerOption(handlerEndpointsKey{}, md)
+}
 
 type handlerOptions struct {
 	headers []string

request.go

@@ -3,9 +3,9 @@ package http
 import (
 	"io"
 
-	"go.unistack.org/micro/v3/codec"
-	"go.unistack.org/micro/v3/metadata"
-	"go.unistack.org/micro/v3/server"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v4/server"
 )
 
 var (

server.go

@@ -7,7 +7,7 @@ import (
 	"unicode"
 	"unicode/utf8"
 
-	"go.unistack.org/micro/v3/server"
+	"go.unistack.org/micro/v4/server"
 )
 
 type methodType struct {

subscriber.go

@@ -7,11 +7,11 @@ import (
 	"reflect"
 	"strings"
 
-	"go.unistack.org/micro/v3/broker"
-	"go.unistack.org/micro/v3/codec"
-	"go.unistack.org/micro/v3/metadata"
-	"go.unistack.org/micro/v3/register"
-	"go.unistack.org/micro/v3/server"
+	"go.unistack.org/micro/v4/broker"
+	"go.unistack.org/micro/v4/codec"
+	"go.unistack.org/micro/v4/metadata"
+	"go.unistack.org/micro/v4/register"
+	"go.unistack.org/micro/v4/server"
 )
 
 var typeOfError = reflect.TypeOf((*error)(nil)).Elem()

util.go

@@ -5,8 +5,8 @@ import (
 	"net/http"
 	"strings"
 
-	"go.unistack.org/micro/v3/metadata"
-	rutil "go.unistack.org/micro/v3/util/reflect"
+	"go.unistack.org/micro/v4/metadata"
+	rutil "go.unistack.org/micro/v4/util/reflect"
 )
 
 func FillRequest(ctx context.Context, req interface{}, opts ...FillRequestOption) error {

util_test.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 	"testing"
 
-	"go.unistack.org/micro/v3/metadata"
+	"go.unistack.org/micro/v4/metadata"
 )
 
 func TestFillrequest(t *testing.T) {