add buildpack detect handler

api/server/handlers/gitinstallation/get_buildpack.go

@@ -0,0 +1,106 @@
+package gitinstallation
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/google/go-github/github"
+	"github.com/porter-dev/porter/api/server/authz"
+	"github.com/porter-dev/porter/api/server/handlers"
+	"github.com/porter-dev/porter/api/server/shared"
+	"github.com/porter-dev/porter/api/server/shared/apierrors"
+	"github.com/porter-dev/porter/api/server/shared/config"
+	"github.com/porter-dev/porter/api/server/shared/requestutils"
+	"github.com/porter-dev/porter/api/types"
+)
+
+type GithubGetBuildpackHandler struct {
+	handlers.PorterHandlerReadWriter
+	authz.KubernetesAgentGetter
+}
+
+func NewGithubGetBuildpackHandler(
+	config *config.Config,
+	decoderValidator shared.RequestDecoderValidator,
+	writer shared.ResultWriter,
+) *GithubGetBuildpackHandler {
+	return &GithubGetBuildpackHandler{
+		PorterHandlerReadWriter: handlers.NewDefaultPorterHandler(config, decoderValidator, writer),
+	}
+}
+
+func (c *GithubGetBuildpackHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	request := &types.GetBuildpackRequest{}
+
+	ok := c.DecodeAndValidate(w, r, request)
+
+	if !ok {
+		return
+	}
+
+	owner, name, ok := GetOwnerAndNameParams(c, w, r)
+
+	if !ok {
+		return
+	}
+
+	branch, reqErr := requestutils.GetURLParamString(r, types.URLParamGitBranch)
+
+	if reqErr != nil {
+		c.HandleAPIError(w, r, reqErr)
+		return
+	}
+
+	client, err := GetGithubAppClientFromRequest(c.Config(), r)
+
+	if err != nil {
+		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
+		return
+	}
+
+	repoContentOptions := github.RepositoryContentGetOptions{}
+	repoContentOptions.Ref = branch
+	_, directoryContents, _, err := client.Repositories.GetContents(
+		context.Background(),
+		owner,
+		name,
+		request.Dir,
+		&repoContentOptions,
+	)
+
+	if err != nil {
+		c.HandleAPIError(w, r, apierrors.NewErrInternal(err))
+		return
+	}
+
+	var BREQS = map[string]string{
+		"requirements.txt": "Python",
+		"Gemfile":          "Ruby",
+		"package.json":     "Node.js",
+		"pom.xml":          "Java",
+		"composer.json":    "PHP",
+	}
+
+	res := &types.GetBuildpackResponse{
+		Valid: true,
+	}
+
+	matches := 0
+
+	for i := range directoryContents {
+		name := *directoryContents[i].Name
+
+		bname, ok := BREQS[name]
+		if ok {
+			matches++
+			res.Name = bname
+		}
+	}
+
+	if matches != 1 {
+		res.Valid = false
+		res.Name = ""
+	}
+
+	c.WriteResult(w, r, res)
+}

api/server/handlers/gitinstallation/helpers.go

@@ -5,7 +5,9 @@ import (
 
 	"github.com/bradleyfalzon/ghinstallation"
 	"github.com/google/go-github/github"
+	"github.com/porter-dev/porter/api/server/handlers"
 	"github.com/porter-dev/porter/api/server/shared/config"
+	"github.com/porter-dev/porter/api/server/shared/requestutils"
 	"github.com/porter-dev/porter/api/types"
 	"github.com/porter-dev/porter/internal/models"
 	"github.com/porter-dev/porter/internal/models/integrations"
@@ -70,3 +72,22 @@ func GetGithubAppClientFromRequest(config *config.Config, r *http.Request) (*git
 
 	return github.NewClient(&http.Client{Transport: itr}), nil
 }
+
+// GetOwnerAndNameParams gets the owner and name ref for the Github repo
+func GetOwnerAndNameParams(c handlers.PorterHandler, w http.ResponseWriter, r *http.Request) (string, string, bool) {
+	owner, reqErr := requestutils.GetURLParamString(r, types.URLParamGitRepoOwner)
+
+	if reqErr != nil {
+		c.HandleAPIError(w, r, reqErr)
+		return "", "", false
+	}
+
+	name, reqErr := requestutils.GetURLParamString(r, types.URLParamGitRepoName)
+
+	if reqErr != nil {
+		c.HandleAPIError(w, r, reqErr)
+		return "", "", false
+	}
+
+	return owner, name, true
+}

api/server/handlers/gitinstallation/list_branches.go

@@ -11,7 +11,6 @@ import (
 	"github.com/porter-dev/porter/api/server/shared"
 	"github.com/porter-dev/porter/api/server/shared/apierrors"
 	"github.com/porter-dev/porter/api/server/shared/config"
-	"github.com/porter-dev/porter/api/server/shared/requestutils"
 	"github.com/porter-dev/porter/api/types"
 )
 
@@ -30,15 +29,9 @@ func NewGithubListBranchesHandler(
 }
 
 func (c *GithubListBranchesHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	owner, reqErr := requestutils.GetURLParamString(r, types.URLParamGitRepoOwner)
+	owner, name, ok := GetOwnerAndNameParams(c, w, r)
 
-	if reqErr != nil {
-		return
-	}
-
-	name, reqErr := requestutils.GetURLParamString(r, types.URLParamGitRepoName)
-
-	if reqErr != nil {
+	if !ok {
 		return
 	}
 

api/server/router/git_installation.go

@@ -120,7 +120,7 @@ func getGitInstallationRoutes(
 			Path: &types.Path{
 				Parent: basePath,
 				RelativePath: fmt.Sprintf(
-					"%s/repos/%s/%s/%s/branches",
+					"%s/repos/{%s}/{%s}/{%s}/branches",
 					relPath,
 					types.URLParamGitKind,
 					types.URLParamGitRepoOwner,
@@ -146,5 +146,42 @@ func getGitInstallationRoutes(
 		Router:   r,
 	})
 
+	//  GET /api/projects/{project_id}/gitrepos/{installation_id}/repos/{kind}/{owner}/{name}/{branch}/buildpack/detect ->
+	// gitinstallation.NewGithubGetBuildpackHandler
+	getBuildpackEndpoint := factory.NewAPIEndpoint(
+		&types.APIRequestMetadata{
+			Verb:   types.APIVerbGet,
+			Method: types.HTTPVerbGet,
+			Path: &types.Path{
+				Parent: basePath,
+				RelativePath: fmt.Sprintf(
+					"%s/repos/{%s}/{%s}/{%s}/{%s}/buildpack/detect",
+					relPath,
+					types.URLParamGitKind,
+					types.URLParamGitRepoOwner,
+					types.URLParamGitRepoName,
+					types.URLParamGitBranch,
+				),
+			},
+			Scopes: []types.PermissionScope{
+				types.UserScope,
+				types.ProjectScope,
+				types.GitInstallationScope,
+			},
+		},
+	)
+
+	getBuildpackHandler := gitinstallation.NewGithubGetBuildpackHandler(
+		config,
+		factory.GetDecoderValidator(),
+		factory.GetResultWriter(),
+	)
+
+	routes = append(routes, &Route{
+		Endpoint: getBuildpackEndpoint,
+		Handler:  getBuildpackHandler,
+		Router:   r,
+	})
+
 	return routes, newPath
 }

api/types/git_installation.go

@@ -26,6 +26,16 @@ const (
 	URLParamGitKind      URLParam = "kind"
 	URLParamGitRepoOwner URLParam = "owner"
 	URLParamGitRepoName  URLParam = "name"
+	URLParamGitBranch    URLParam = "branch"
 )
 
 type ListRepoBranchesResponse []string
+
+type GetBuildpackRequest struct {
+	Dir string `schema:"dir" form:"required"`
+}
+
+type GetBuildpackResponse struct {
+	Valid bool   `json:"valid"`
+	Name  string `json:"name"`
+}

docs/developing/backend-refactor-status.md

@@ -53,7 +53,7 @@
 | <li>- [X] `GET /api/projects/{project_id}/gitrepos`                                                                         | AB          |                 |             |                  |
 | <li>- [X] `GET /api/projects/{project_id}/gitrepos/{installation_id}/repos`                                                 | AB          |                 |             |                  |
 | <li>- [X] `GET /api/projects/{project_id}/gitrepos/{installation_id}/repos/{kind}/{owner}/{name}/branches`                  | AB          |                 |             |                  |
-| <li>- [ ] `GET /api/projects/{project_id}/gitrepos/{installation_id}/repos/{kind}/{owner}/{name}/{branch}/buildpack/detect` |             |                 |             |                  |
+| <li>- [X] `GET /api/projects/{project_id}/gitrepos/{installation_id}/repos/{kind}/{owner}/{name}/{branch}/buildpack/detect` | AB          |                 |             |                  |
 | <li>- [ ] `GET /api/projects/{project_id}/gitrepos/{installation_id}/repos/{kind}/{owner}/{name}/{branch}/contents`         |             |                 |             |                  |
 | <li>- [ ] `GET /api/projects/{project_id}/gitrepos/{installation_id}/repos/{kind}/{owner}/{name}/{branch}/procfile`         |             |                 |             |                  |
 | <li>- [ ] `GET /api/projects/{project_id}/gitrepos/{installation_id}/repos/{kind}/{owner}/{name}/{branch}/tarball_url`      |             |                 |             |                  |