feat: [AH-2542]: added readme api for nuget

registry/app/api/controller/pkg/nuget/controller.go

@@ -73,6 +73,8 @@ type Controller interface {
 	CountPackageV2(ctx context.Context, info nugettype.ArtifactInfo, searchTerm string) *EntityCountResponse
 
 	GetServiceMetadataV2(ctx context.Context, info nugettype.ArtifactInfo) *GetServiceMetadataV2Response
+
+	GetReadme(ctx context.Context, info nugettype.ArtifactInfo) *GetReadmeResponse
 }
 
 // Controller handles Python package operations.

registry/app/api/controller/pkg/nuget/get_readme.go

@@ -0,0 +1,90 @@
+//  Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// 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.
+
+package nuget
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/harness/gitness/registry/app/pkg"
+	"github.com/harness/gitness/registry/app/pkg/base"
+	"github.com/harness/gitness/registry/app/pkg/commons"
+	"github.com/harness/gitness/registry/app/pkg/nuget"
+	"github.com/harness/gitness/registry/app/pkg/response"
+	nugettype "github.com/harness/gitness/registry/app/pkg/types/nuget"
+	registrytypes "github.com/harness/gitness/registry/types"
+)
+
+func (c *controller) GetReadme(
+	ctx context.Context,
+	info nugettype.ArtifactInfo,
+) *GetReadmeResponse {
+	f := func(registry registrytypes.Registry, a pkg.Artifact) response.Response {
+		info.RegIdentifier = registry.Name
+		info.RegistryID = registry.ID
+		nugetRegistry, ok := a.(nuget.Registry)
+		if !ok {
+			return &GetReadmeResponse{
+				BaseResponse{
+					fmt.Errorf("invalid registry type: expected nuget.Registry"),
+					nil,
+				}, "",
+			}
+		}
+		readmeContent, err := nugetRegistry.GetReadme(ctx, info)
+		if err != nil {
+			return &GetReadmeResponse{
+				BaseResponse{
+					err,
+					nil,
+				}, "",
+			}
+		}
+
+		headers := &commons.ResponseHeaders{
+			Headers: map[string]string{
+				"Content-Type": "text/markdown; charset=utf-8",
+			},
+		}
+
+		return &GetReadmeResponse{
+			BaseResponse{
+				nil,
+				headers,
+			}, readmeContent,
+		}
+	}
+
+	result, err := base.NoProxyWrapper(ctx, c.registryDao, f, info)
+
+	if err != nil {
+		return &GetReadmeResponse{
+			BaseResponse{
+				err,
+				nil,
+			}, "",
+		}
+	}
+	readmeResponse, ok := result.(*GetReadmeResponse)
+	if !ok {
+		return &GetReadmeResponse{
+			BaseResponse{
+				fmt.Errorf("invalid response type: expected GetReadmeResponse"),
+				nil,
+			}, "",
+		}
+	}
+	return readmeResponse
+}

registry/app/api/controller/pkg/nuget/response.go

@@ -107,3 +107,8 @@ type GetPackageVersionMetadataResponse struct {
 	BaseResponse
 	RegistrationLeafResponse *nuget.RegistrationLeafResponse
 }
+
+type GetReadmeResponse struct {
+	BaseResponse
+	ReadmeContent string
+}

registry/app/api/handler/nuget/handler.go

@@ -15,6 +15,7 @@
 package nuget
 
 import (
+	"fmt"
 	"net/http"
 	"strings"
 
@@ -33,6 +34,7 @@ type Handler interface {
 	UploadSymbolPackage(writer http.ResponseWriter, request *http.Request)
 	DownloadPackage(http.ResponseWriter, *http.Request)
 	DeletePackage(writer http.ResponseWriter, request *http.Request)
+	GetReadme(writer http.ResponseWriter, request *http.Request)
 	GetServiceEndpoint(http.ResponseWriter, *http.Request)
 	GetServiceEndpointV2(http.ResponseWriter, *http.Request)
 	ListPackageVersion(http.ResponseWriter, *http.Request)
@@ -92,3 +94,36 @@ func (h *handler) GetPackageArtifactInfo(r *http.Request) (pkg.PackageArtifactIn
 		NestedPath:    strings.TrimSuffix(r.PathValue("*"), "/"),
 	}, nil
 }
+
+func (h *handler) GetReadme(writer http.ResponseWriter, request *http.Request) {
+	ctx := request.Context()
+
+	// Get artifact info from request
+	info, err := h.GetPackageArtifactInfo(request)
+	if err != nil {
+		h.HandleErrors(ctx, []error{err}, writer)
+		return
+	}
+
+	nugetInfo, ok := info.(*nugettype.ArtifactInfo)
+	if !ok {
+		h.HandleErrors(ctx, []error{fmt.Errorf("failed to fetch info from context")}, writer)
+		return
+	}
+
+	// Call controller to get readme
+	response := h.controller.GetReadme(ctx, *nugetInfo)
+	if response.Error != nil {
+		h.HandleError(ctx, writer, response.Error)
+		return
+	}
+
+	// Write response headers
+	if response.ResponseHeaders != nil {
+		response.ResponseHeaders.WriteHeadersToResponse(writer)
+	}
+
+	// Write readme content
+	writer.WriteHeader(http.StatusOK)
+	_, _ = writer.Write([]byte(response.ReadmeContent))
+}

registry/app/api/router/packages/route.go

@@ -212,6 +212,9 @@ func NewRouter(
 			r.With(middleware.StoreArtifactInfo(nugetHandler)).
 				With(middleware.RequestNugetPackageAccess(packageHandler, enum.PermissionArtifactsDownload)).
 				Get("/Packages(Id='{id:[^']+}',Version='{version:[^']+}')", nugetHandler.GetPackageVersionMetadataV2)
+			r.With(middleware.StoreArtifactInfo(nugetHandler)).
+				With(middleware.RequestNugetPackageAccess(packageHandler, enum.PermissionArtifactsDownload)).
+				Get("/{id}/{version}/readme", nugetHandler.GetReadme)
 			r.With(middleware.StoreArtifactInfo(nugetHandler)).
 				With(middleware.RequestNugetPackageAccess(packageHandler, enum.PermissionArtifactsDownload)).
 				Get("/registration/{id}/{version}", nugetHandler.GetPackageVersionMetadata)

registry/app/pkg/nuget/helper.go

@@ -64,6 +64,10 @@ func buildServiceEndpoint(baseURL string) *nuget.ServiceEndpoint {
 				ID:   baseURL + "/package",
 				Type: "PackageBaseAddress/3.0.0",
 			},
+			{
+				ID:   baseURL + "/{lower_id}/{lower_version}/readme",
+				Type: "ReadmeUriTemplate/6.13.0",
+			},
 			{
 				ID:   baseURL,
 				Type: "PackagePublish/2.0.0",
@@ -128,6 +132,11 @@ func getPackageDownloadURL(baseURL, id, version string) string {
 	return fmt.Sprintf("%s/package/%s/%s/%s.%s.nupkg", baseURL, id, version, id, version)
 }
 
+// getReadmeURL builds the readme url.
+func getReadmeURL(baseURL, id, version string) string {
+	return fmt.Sprintf("%s/%s/%s/readme", baseURL, id, version)
+}
+
 // GetPackageMetadataURL builds the package metadata url.
 func getPackageMetadataURL(baseURL, id, version string) string {
 	return fmt.Sprintf("%s/Packages(Id='%s',Version='%s')", baseURL, id, version)
@@ -672,6 +681,7 @@ func createRegistrationIndexPageItem(baseURL string, info nuget.ArtifactInfo, ar
 			Tags:                     metadata.PackageMetadata.Tags,
 			Title:                    metadata.PackageMetadata.Title,
 			Published:                artifact.CreatedAt.Format(time.RFC3339),
+			ReadmeURL:                getReadmeURL(baseURL, info.Image, artifact.Version),
 		},
 	}
 	return res, nil

registry/app/pkg/nuget/local.go

@@ -16,6 +16,7 @@ package nuget
 
 import (
 	"context"
+	"encoding/json"
 	"encoding/xml"
 	"errors"
 	"fmt"
@@ -331,7 +332,7 @@ func (c *localRegistry) buildMetadata(fileReader io.Reader) (metadata nugetmetad
 			if err != nil {
 				return metadata, fmt.Errorf("failed to parse metadata from .nuspec file: %w", err2)
 			}
-		} else if strings.HasSuffix(header.Name, "README.md") {
+		} else if strings.HasSuffix(strings.ToLower(header.Name), "readme.md") {
 			readme, err2 = c.parseReadme(zr)
 			if err2 != nil {
 				return metadata, fmt.Errorf("failed to parse metadata from README.md file: %w", err2)
@@ -447,3 +448,30 @@ func (c *localRegistry) GetArtifactType() apicontract.RegistryType {
 func (c *localRegistry) GetPackageTypes() []apicontract.PackageType {
 	return []apicontract.PackageType{apicontract.PackageTypeNUGET}
 }
+
+func (c *localRegistry) GetReadme(
+	ctx context.Context,
+	info nugettype.ArtifactInfo,
+) (string, error) {
+	image, err := c.imageDao.GetByName(ctx, info.RegistryID, info.Image)
+	if err != nil {
+		return "", fmt.Errorf("failed to get image: %w", err)
+	}
+
+	artifact, err := c.artifactDao.GetByName(ctx, image.ID, info.Version)
+	if err != nil {
+		return "", fmt.Errorf("failed to get artifact: %w", err)
+	}
+
+	var metadata nugetmetadata.NugetMetadata
+	if err := json.Unmarshal(artifact.Metadata, &metadata); err != nil {
+		return "", fmt.Errorf("failed to unmarshal metadata: %w", err)
+	}
+
+	readmeContent := metadata.Metadata.PackageMetadata.Readme
+	if readmeContent == "" {
+		return "", fmt.Errorf("readme not found for package %s version %s", info.Image, info.Version)
+	}
+
+	return readmeContent, nil
+}

registry/app/pkg/nuget/proxy.go

@@ -517,6 +517,14 @@ func (r *proxy) GetPackageTypes() []artifact.PackageType {
 	return []artifact.PackageType{artifact.PackageTypeNUGET}
 }
 
+func (r *proxy) GetReadme(
+	ctx context.Context,
+	_ nugettype.ArtifactInfo,
+) (string, error) {
+	log.Error().Ctx(ctx).Msg("Not implemented")
+	return "", errcode.ErrCodeInvalidRequest.WithDetail(fmt.Errorf("not implemented"))
+}
+
 func (r *proxy) putFileToLocal(
 	ctx context.Context, info *nugettype.ArtifactInfo,
 	remote RemoteRegistryHelper,

registry/app/pkg/nuget/registry.go

@@ -60,4 +60,6 @@ type Registry interface {
 	GetServiceEndpointV2(ctx context.Context, info nuget.ArtifactInfo) *nuget.ServiceEndpointV2
 
 	GetServiceMetadataV2(ctx context.Context, info nuget.ArtifactInfo) *nuget.ServiceMetadataV2
+
+	GetReadme(ctx context.Context, info nuget.ArtifactInfo) (string, error)
 }

registry/app/pkg/types/nuget/types.go

@@ -373,6 +373,8 @@ type CatalogEntry struct {
 	Tags       string `json:"tags,omitempty"`
 	Title      string `json:"title,omitempty"`
 	Published  string `json:"published,omitempty"`
+	//nolint: tagliatelle
+	ReadmeURL string `json:"readmeUrl,omitempty"`
 }
 
 // https://docs.microsoft.com/en-us/nuget/api/registration-base-url-resource#package-dependency-group