feat: Added REST API for retrieving JSON schema for VPP-Agent configuration

LICENSE

@@ -199,3 +199,9 @@
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
+
+
+Licenses for 3rd party libraries included in code:
+
+1. library protoc-gen-jsonschema (https://github.com/chrusty/protoc-gen-jsonschema) -
+License: Apache License Version 2.0, January 2004 (full license included in plugins/restapi/jsonschema/LICENSE)

README.md

@@ -116,6 +116,10 @@ If you are interested in contributing, please see the [contribution guidelines][
 
 [![GitHub license](https://img.shields.io/badge/license-Apache%20license%202.0-blue.svg)](https://github.com/ligato/vpp-agent/blob/master/LICENSE)
 
+## Modified 3rd party tools included
+
+ - [protoc-gen-jsonschema][tool-included-jsonchema] ([code location in this repository][local-place-for-jsonchema])
+
 [agentctl]: cmd/agentctl
 [cn-infra]: https://github.com/ligato/cn-infra
 [contiv-vpp]: https://github.com/contiv/vpp
@@ -131,3 +135,5 @@ If you are interested in contributing, please see the [contribution guidelines][
 [vpp]: https://fd.io/vppproject/vpptech/
 [vpp-agent]: https://hub.docker.com/r/ligato/vpp-agent
 [vpp-agent-arm64]: https://hub.docker.com/r/ligato/vpp-agent-arm64
+[tool-included-jsonchema]: https://github.com/chrusty/protoc-gen-jsonschema/tree/de75f1b59c4e0f5d5edf7be2a18d1c8e4d81b17a
+[local-place-for-jsonchema]: plugins/restapi/jsonschema

go.mod

@@ -5,6 +5,7 @@ go 1.13
 require (
 	git.fd.io/govpp.git v0.3.6-0.20200907135408-e517439567ad
 	github.com/Shopify/sarama v1.20.1 // indirect
+	github.com/alecthomas/jsonschema v0.0.0-20200217214135-7152f22193c9
 	github.com/alicebob/miniredis v2.5.0+incompatible // indirect
 	github.com/common-nighthawk/go-figure v0.0.0-20200609044655-c4b36f998cf2
 	github.com/coreos/bbolt v1.3.3 // indirect
@@ -26,6 +27,7 @@ require (
 	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0
 	github.com/grpc-ecosystem/grpc-gateway v1.11.3 // indirect
 	github.com/hashicorp/go-uuid v1.0.1 // indirect
+	github.com/iancoleman/orderedmap v0.0.0-20190318233801-ac98e3ecb4b0
 	github.com/jhump/protoreflect v1.7.0
 	github.com/lunixbochs/struc v0.0.0-20200521075829-a4cb8d33dbbe
 	github.com/mitchellh/go-ps v0.0.0-20170309133038-4fdf99ab2936
@@ -44,6 +46,9 @@ require (
 	github.com/unrolled/render v0.0.0-20180914162206-b9786414de4d
 	github.com/vishvananda/netlink v0.0.0-20180910184128-56b1bd27a9a3
 	github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc
+	github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb // indirect
+	github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 // indirect
+	github.com/xeipuuv/gojsonschema v1.1.0
 	github.com/yuin/gopher-lua v0.0.0-20190514113301-1cd887cd7036 // indirect
 	go.ligato.io/cn-infra/v2 v2.5.0-alpha.0.20200313154441-b0d4c1b11c73
 	go.uber.org/multierr v1.2.0 // indirect

go.sum

@@ -22,6 +22,8 @@ github.com/Shopify/sarama v1.20.1/go.mod h1:FVkBWblsNy7DGZRfXLU0O9RCGt5g3g3yEuWX
 github.com/Shopify/toxiproxy v2.1.4+incompatible h1:TKdv8HiTLgE5wdJuEML90aBgNWsokNbMijUGhmcoBJc=
 github.com/Shopify/toxiproxy v2.1.4+incompatible/go.mod h1:OXgGpZ6Cli1/URJOF1DMxUHB2q5Ap20/P/eIdh4G0pI=
 github.com/Songmu/prompter v0.0.0-20150725163906-b5721e8d5566/go.mod h1:fNhSFBGC+sg+dZ7AqDHgq+xYiom23TeTESzUbO7PIrE=
+github.com/alecthomas/jsonschema v0.0.0-20200217214135-7152f22193c9 h1:h+KAZEUnNceFhqyH46BgwH4lk8m6pdR/3x3h7IPn7VA=
+github.com/alecthomas/jsonschema v0.0.0-20200217214135-7152f22193c9/go.mod h1:/n6+1/DWPltRLWL/VKyUxg6tzsl5kHUCcraimt4vr60=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf h1:qet1QNfXsQxTZqLG4oE62mJzwPIB8+Tee4RNCL9ulrY=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
@@ -51,6 +53,8 @@ github.com/bsm/sarama-cluster v2.1.15+incompatible/go.mod h1:r7ao+4tTNXvWm+VRpRJ
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
+github.com/chrusty/protoc-gen-jsonschema v0.0.0-20201201182816-de75f1b59c4e h1:VEDA+FrTIUnlSpMlo2i1e0L1hP45vek2ED+blYdOrxg=
+github.com/chrusty/protoc-gen-jsonschema v0.0.0-20201201182816-de75f1b59c4e/go.mod h1:qYuJI3Nz/kjHcigPikCSSeh+pRGcCiT1U6qzWGEmaJ4=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
 github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
 github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
@@ -266,6 +270,8 @@ github.com/howeyc/crc16 v0.0.0-20171223171357-2b2a61e366a6 h1:IIVxLyDUYErC950b8k
 github.com/howeyc/crc16 v0.0.0-20171223171357-2b2a61e366a6/go.mod h1:JslaLRrzGsOKJgFEPBP65Whn+rdwDQSk0I0MCRFe2Zw=
 github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
+github.com/iancoleman/orderedmap v0.0.0-20190318233801-ac98e3ecb4b0 h1:i462o439ZjprVSFSZLZxcsoAe592sZB1rci2Z8j4wdk=
+github.com/iancoleman/orderedmap v0.0.0-20190318233801-ac98e3ecb4b0/go.mod h1:N0Wam8K1arqPXNWjMo21EXnBPOPp36vB07FNRdD2geA=
 github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
@@ -281,6 +287,7 @@ github.com/kisielk/errcheck v1.2.0/go.mod h1:/BMXB+zMLi60iA8Vv6Ksmxu/1UDYcXs4uQL
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/konsorten/go-windows-terminal-sequences v1.0.2/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
@@ -447,6 +454,7 @@ github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.3.1-0.20190311161405-34c6fa2dc709/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/tinylib/msgp v1.0.2 h1:DfdQrzQa7Yh2es9SuLkixqxuXS2SxsdYn0KbdrOGWD8=
@@ -464,6 +472,14 @@ github.com/vishvananda/netlink v0.0.0-20180910184128-56b1bd27a9a3/go.mod h1:+SR5
 github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc h1:R83G5ikgLMxrBvLh22JhdfI8K6YXEPHx5P03Uu3DRs4=
 github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc/go.mod h1:ZjcWmFBXmLKZu9Nxj3WKYEafiSqer2rnvPr0en9UNpI=
 github.com/willfaught/gockle v0.0.0-20160623235217-4f254e1e0f0a/go.mod h1:NLcF+3nDpXVIZatjn5Z97gKzFFVU7TzgbAcs8G7/Jrs=
+github.com/xeipuuv/gojsonpointer v0.0.0-20190809123943-df4f5c81cb3b h1:6cLsL+2FW6dRAdl5iMtHgRogVCff0QpRi9653YmdcJA=
+github.com/xeipuuv/gojsonpointer v0.0.0-20190809123943-df4f5c81cb3b/go.mod h1:N2zxlSyiKSe5eX1tZViRH5QA0qijqEDrYZiPEAiq3wU=
+github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb h1:zGWFAtiMcyryUHoUjUJX0/lt1H2+i2Ka2n+D3DImSNo=
+github.com/xeipuuv/gojsonpointer v0.0.0-20190905194746-02993c407bfb/go.mod h1:N2zxlSyiKSe5eX1tZViRH5QA0qijqEDrYZiPEAiq3wU=
+github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415 h1:EzJWgHovont7NscjpAxXsDA8S8BMYve8Y5+7cuRE7R0=
+github.com/xeipuuv/gojsonreference v0.0.0-20180127040603-bd5ef7bd5415/go.mod h1:GwrjFmJcFw6At/Gs6z4yjiIwzuJ1/+UwLxMQDVQXShQ=
+github.com/xeipuuv/gojsonschema v1.1.0 h1:ngVtJC9TY/lg0AA/1k48FYhBrhRoFlEmWzsehpNAaZg=
+github.com/xeipuuv/gojsonschema v1.1.0/go.mod h1:5yf86TLmAcydyeJq5YvxkGPE2fm/u4myDekKRoLuqhs=
 github.com/xiang90/probing v0.0.0-20160813154853-07dd2e8dfe18/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 h1:eY9dn8+vbi4tKz5Qo6v2eYzo7kUS51QINcR5jNpbZS8=
 github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
@@ -560,6 +576,7 @@ golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190502145724-3ef323f4f1fd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190514135907-3a4b5fb9f71f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190826190057-c7b8b68b1456/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190904154756-749cb33beabd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=

plugins/restapi/handlers.go

@@ -17,19 +17,29 @@
 package restapi
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"net/http"
 	"runtime"
+	"strings"
 
 	"github.com/go-errors/errors"
+	"github.com/golang/protobuf/proto"
+	protoc_plugin "github.com/golang/protobuf/protoc-gen-go/plugin"
 	"github.com/unrolled/render"
 
+	"go.ligato.io/cn-infra/v2/logging/logrus"
+	"go.ligato.io/vpp-agent/v3/client"
 	"go.ligato.io/vpp-agent/v3/cmd/agentctl/api/types"
 	"go.ligato.io/vpp-agent/v3/pkg/version"
 	"go.ligato.io/vpp-agent/v3/plugins/configurator"
+	"go.ligato.io/vpp-agent/v3/plugins/restapi/jsonschema/converter"
 	"go.ligato.io/vpp-agent/v3/plugins/restapi/resturl"
 	interfaces "go.ligato.io/vpp-agent/v3/proto/ligato/vpp/interfaces"
+	"google.golang.org/protobuf/reflect/protodesc"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/types/descriptorpb"
 )
 
 var (
@@ -40,6 +50,7 @@ var (
 
 func (p *Plugin) registerInfoHandlers() {
 	p.HTTPHandlers.RegisterHTTPHandler(resturl.Version, p.versionHandler, GET)
+	p.HTTPHandlers.RegisterHTTPHandler(resturl.JSONSchema, p.jsonSchemaHandler, GET)
 }
 
 // Registers ABF REST handler
@@ -315,6 +326,123 @@ func (p *Plugin) registerHTTPHandler(key, method string, f func() (interface{},
 	p.HTTPHandlers.RegisterHTTPHandler(key, handlerFunc, method)
 }
 
+// jsonSchemaHandler returns JSON schema of VPP-Agent configuration.
+func (p *Plugin) jsonSchemaHandler(formatter *render.Render) http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
+		// create FileDescriptorProto for dynamic Config holding all VPP-Agent configuration
+		knownModels, err := client.LocalClient.KnownModels("config") // locally registered models
+		if err != nil {
+			errMsg := fmt.Sprintf("500 Internal server error: "+
+				"can't get registered models: %v\n", err)
+			p.Log.Error(errMsg)
+			p.logError(formatter.JSON(w, http.StatusInternalServerError, errMsg))
+			return
+		}
+		config, err := client.NewDynamicConfig(knownModels)
+		if err != nil {
+			errMsg := fmt.Sprintf("500 Internal server error: "+
+				"can't create dynamic config due to: %v\n", err)
+			p.Log.Error(errMsg)
+			p.logError(formatter.JSON(w, http.StatusInternalServerError, errMsg))
+			return
+		}
+		dynConfigFileDescProto := protodesc.ToFileDescriptorProto(config.ProtoReflect().Descriptor().ParentFile())
+
+		// create list of all FileDescriptorProtos (imports should be before converted proto file -> dynConfig is last)
+		fileDescriptorProtos := allFileDescriptorProtos(knownModels)
+		fileDescriptorProtos = append(fileDescriptorProtos, dynConfigFileDescProto)
+
+		// creating input for protoc's plugin (code extracted in plugins/restapi/jsonschema) that can convert
+		// FileDescriptorProtos to JSONSchema
+		params := "messages=[Dynamic_config]" + // targeting only the main config message (proto file has also other messages)
+			",disallow_additional_properties" + // additional unknown json fields makes configuration applying fail
+			",proto_and_json_fieldnames" // allow also proto names for fields
+		cgReq := &protoc_plugin.CodeGeneratorRequest{
+			ProtoFile:       fileDescriptorProtos,
+			FileToGenerate:  []string{dynConfigFileDescProto.GetName()},
+			Parameter:       &params,
+			CompilerVersion: nil, // compiler version is not need in this protoc plugin
+		}
+		cgReqMarshalled, err := proto.Marshal(cgReq)
+		if err != nil {
+			fmt.Errorf("can't proto marshal to: %w", err)
+			errMsg := fmt.Sprintf("500 Internal server error: "+
+				"can't proto marshal CodeGeneratorRequest: %v\n", err)
+			p.Log.Error(errMsg)
+			p.logError(formatter.JSON(w, http.StatusInternalServerError, errMsg))
+			return
+		}
+
+		// use JSON schema converter and handle error cases
+		p.Log.Debug("Processing code generator request")
+		protoConverter := converter.New(logrus.DefaultLogger().StandardLogger())
+		res, err := protoConverter.ConvertFrom(bytes.NewReader(cgReqMarshalled))
+		if err != nil {
+			if res == nil {
+				errMsg := fmt.Sprintf("500 Internal server error: "+
+					"failed to read registered model configuration input: %v\n", err)
+				p.Log.Error(errMsg)
+				p.logError(formatter.JSON(w, http.StatusInternalServerError, errMsg))
+				return
+			}
+			errMsg := fmt.Sprintf("500 Internal server error: "+
+				"failed generate JSON schema: %v (%v)\n", res.Error, err)
+			p.Log.Error(errMsg)
+			p.logError(formatter.JSON(w, http.StatusInternalServerError, errMsg))
+			return
+		}
+
+		// extract json schema
+		// (protoc_plugin.CodeGeneratorResponse could have cut the file content into multiple pieces
+		// for performance optimization (due to godoc), but we know that all pieces are only one file
+		// due to requesting one file -> join all content together)
+		var sb strings.Builder
+		for _, file := range res.File {
+			sb.WriteString(file.GetContent())
+		}
+
+		// writing response
+		// (jsonschema is in raw form (string) and non of the available format renders supports raw data output
+		// with customizable content type setting in header -> custom handling)
+		w.Header().Set(render.ContentType, render.ContentJSON+"; charset=UTF-8")
+		w.Write([]byte(sb.String())) // will also call WriteHeader(http.StatusOK) automatically
+	}
+}
+
+// allImports retrieves all imports from given FileDescriptor including transitive imports (import
+// duplication can occur)
+func allImports(fileDesc protoreflect.FileDescriptor) []protoreflect.FileDescriptor {
+	result := make([]protoreflect.FileDescriptor, 0)
+	imports := fileDesc.Imports()
+	for i := 0; i < imports.Len(); i++ {
+		currentImport := imports.Get(i).FileDescriptor
+		result = append(result, currentImport)
+		result = append(result, allImports(currentImport)...)
+	}
+	return result
+}
+
+// allFileDescriptorProtos retrieves all FileDescriptorProtos related to given models (including
+// all imported proto files)
+func allFileDescriptorProtos(knownModels []*client.ModelInfo) []*descriptorpb.FileDescriptorProto {
+	// extract all FileDescriptors for given known models (including direct and transitive file imports)
+	fileDescriptors := make(map[string]protoreflect.FileDescriptor) // using map for deduplication
+	for _, knownModel := range knownModels {
+		protoFile := knownModel.MessageDescriptor.ParentFile()
+		fileDescriptors[protoFile.Path()] = protoFile
+		for _, importProtoFile := range allImports(protoFile) {
+			fileDescriptors[importProtoFile.Path()] = importProtoFile
+		}
+	}
+
+	// convert retrieved FileDescriptors to FileDescriptorProtos
+	fileDescriptorProtos := make([]*descriptorpb.FileDescriptorProto, 0, len(knownModels))
+	for _, fileDescriptor := range fileDescriptors {
+		fileDescriptorProtos = append(fileDescriptorProtos, protodesc.ToFileDescriptorProto(fileDescriptor))
+	}
+	return fileDescriptorProtos
+}
+
 // versionHandler returns version of Agent.
 func (p *Plugin) versionHandler(formatter *render.Render) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {