github.com/yrj2011/jx-test-infra@v0.0.0-20190529031832-7a2065ee98eb/prow/prstatus/prstatus.go

/*
Copyright 2018 The Kubernetes Authors.

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 prstatus

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"

	gogithub "github.com/google/go-github/github"
	"github.com/shurcooL/githubv4"
	"github.com/sirupsen/logrus"
	"golang.org/x/oauth2"

	"k8s.io/test-infra/ghclient"
	"k8s.io/test-infra/prow/config"
	"k8s.io/test-infra/prow/github"
)

const (
	loginSession   = "github_login"
	githubEndpoint = "https://api.github.com"
	tokenSession   = "access-token-session"
	tokenKey       = "access-token"
	loginKey       = "login"
)

type githubClient interface {
	Query(context.Context, interface{}, map[string]interface{}) error
	GetCombinedStatus(org, repo, ref string) (*github.CombinedStatus, error)
}

// PullRequestQueryHandler defines an interface that query handlers should implement.
type PullRequestQueryHandler interface {
	HeadContexts(ghc githubClient, pr PullRequest) ([]Context, error)
	QueryPullRequests(context.Context, githubClient, string) ([]PullRequest, error)
	GetUser(*ghclient.Client) (*gogithub.User, error)
}

// UserData represents data returned to client request to the endpoint. It has a flag that indicates
// whether the user has logged in his github or not and list of open pull requests owned by the
// user.
type UserData struct {
	Login                    bool
	PullRequestsWithContexts []PullRequestWithContext
}

// PullRequestWithContext contains a pull request with its latest context.
type PullRequestWithContext struct {
	Contexts    []Context
	PullRequest PullRequest
}

// Dashboard Agent is responsible for handling request to /pr-status endpoint. It will serve
// list of open pull requests owned by the user.
type DashboardAgent struct {
	repos []string
	goac  *config.GithubOAuthConfig

	log *logrus.Entry
}

type Label struct {
	ID   githubv4.ID
	Name githubv4.String
}

// Context represent github contexts.
type Context struct {
	Context     string
	Description string
	State       string
}

// PullRequest holds graphql response data for github pull request.
type PullRequest struct {
	Number githubv4.Int
	Merged githubv4.Boolean
	Title  githubv4.String
	Author struct {
		Login githubv4.String
	}
	BaseRef struct {
		Name   githubv4.String
		Prefix githubv4.String
	}
	HeadRefOID githubv4.String `graphql:"headRefOid"`
	Repository struct {
		Name          githubv4.String
		NameWithOwner githubv4.String
		Owner         struct {
			Login githubv4.String
		}
	}
	Labels struct {
		Nodes []struct {
			Label Label `graphql:"... on Label"`
		}
	} `graphql:"labels(first: 100)"`
	Milestone struct {
		ID     githubv4.ID
		Closed githubv4.Boolean
	}
}

type UserLoginQuery struct {
	Viewer struct {
		Login githubv4.String
	}
}

type searchQuery struct {
	RateLimit struct {
		Cost      githubv4.Int
		Remaining githubv4.Int
	}
	Search struct {
		PageInfo struct {
			HasNextPage githubv4.Boolean
			EndCursor   githubv4.String
		}
		Nodes []struct {
			PullRequest PullRequest `graphql:"... on PullRequest"`
		}
	} `graphql:"search(type: ISSUE, first: 100, after: $searchCursor, query: $query)"`
}

// Returns new user dashboard agent.
func NewDashboardAgent(repos []string, config *config.GithubOAuthConfig, log *logrus.Entry) *DashboardAgent {
	return &DashboardAgent{
		repos: repos,
		goac:  config,
		log:   log,
	}
}

// HandlePrStatus returns a http handler function that handles request to /pr-status
// endpoint. The handler takes user access token stored in the cookie to query to Github on behalf
// of the user and serve the data in return. The Query handler is passed to the method so as it
// can be mocked in the unit test..
func (da *DashboardAgent) HandlePrStatus(queryHandler PullRequestQueryHandler) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		serverError := func(action string, err error) {
			da.log.WithError(err).Errorf("Error %s.", action)
			msg := fmt.Sprintf("500 Internal server error %s: %v", action, err)
			http.Error(w, msg, http.StatusInternalServerError)
		}

		session, err := da.goac.CookieStore.Get(r, tokenSession)
		if err != nil {
			serverError("Error with getting git token session.", err)
			return
		}
		token, ok := session.Values[tokenKey].(*oauth2.Token)
		data := UserData{
			Login: false,
		}

		var user *gogithub.User
		if ok && token.Valid() {
			// If access token exist, get user login using the access token. This is a chance
			// to validate whether the access token is consumable or not. If not, invalidate the
			// session.
			goGithubClient := ghclient.NewClient(token.AccessToken, false)
			var err error
			user, err = queryHandler.GetUser(goGithubClient)
			if err != nil {
				if strings.Contains(err.Error(), "401") {
					// Invalidate access token session
					session.Options.MaxAge = -1
					if err := session.Save(r, w); err != nil {
						serverError("Error with saving invalidated session", err)
						return
					}
					// Invalidate github login session
					http.SetCookie(w, &http.Cookie{
						Name:    loginSession,
						Path:    "/",
						Expires: time.Now().Add(-time.Hour * 24),
						MaxAge:  -1,
						Secure:  true,
					})
				} else {
					serverError("Error with getting user login", err)
					return
				}
			}
		}

		if user != nil {
			login := *user.Login
			data.Login = true
			// Saves login. We save the login under 2 cookies. One for the use of client to render the
			// data and one encoded for server to verify the identity of the authenticated user.
			http.SetCookie(w, &http.Cookie{
				Name:    loginSession,
				Value:   login,
				Path:    "/",
				Expires: time.Now().Add(time.Hour * 24 * 30),
				Secure:  true,
			})
			session.Values[loginKey] = login
			if err := session.Save(r, w); err != nil {
				serverError("Save oauth session", err)
				return
			}

			getSecret := func() []byte {
				return []byte(token.AccessToken)
			}

			// Construct query
			ghc := github.NewClient(getSecret, githubEndpoint)
			query := da.ConstructSearchQuery(login)
			if err := r.ParseForm(); err == nil {
				if q := r.Form.Get("query"); q != "" {
					query = q
				}
			}
			// If neither repo nor org is specified in the search query. We limit the search to repos that
			// are configured with either Prow or Tide.
			if !queryConstrainsRepos(query) {
				for _, v := range da.repos {
					query += fmt.Sprintf(" repo:\"%s\"", v)
				}
			}
			pullRequests, err := queryHandler.QueryPullRequests(context.Background(), ghc, query)
			if err != nil {
				serverError("Error with querying user data.", err)
				return
			}
			var pullRequestWithContexts []PullRequestWithContext
			for _, pr := range pullRequests {
				prcontext, err := queryHandler.HeadContexts(ghc, pr)
				if err != nil {
					serverError("Error with getting head context of pr", err)
					continue
				}
				pullRequestWithContexts = append(pullRequestWithContexts, PullRequestWithContext{
					Contexts:    prcontext,
					PullRequest: pr,
				})
			}

			data.PullRequestsWithContexts = pullRequestWithContexts
		}
		marshaledData, err := json.Marshal(data)
		if err != nil {
			da.log.WithError(err).Error("Error with marshalling user data.")
		}

		if v := r.URL.Query().Get("var"); v != "" {
			fmt.Fprintf(w, "var %s = ", v)
			w.Write(marshaledData)
			io.WriteString(w, ";")
		} else {
			w.Write(marshaledData)
		}
	}
}

// Query function that returns a list of open pull requests owned by the user whose access token
// is consumed by the github client.
func (da *DashboardAgent) QueryPullRequests(ctx context.Context, ghc githubClient, query string) ([]PullRequest, error) {
	var prs []PullRequest
	vars := map[string]interface{}{
		"query":        (githubv4.String)(query),
		"searchCursor": (*githubv4.String)(nil),
	}
	var totalCost int
	var remaining int
	for {
		sq := searchQuery{}
		if err := ghc.Query(ctx, &sq, vars); err != nil {
			return nil, err
		}
		totalCost += int(sq.RateLimit.Cost)
		remaining = int(sq.RateLimit.Remaining)
		for _, n := range sq.Search.Nodes {
			prs = append(prs, n.PullRequest)
		}
		if !sq.Search.PageInfo.HasNextPage {
			break
		}
		vars["searchCursor"] = githubv4.NewString(sq.Search.PageInfo.EndCursor)
	}
	da.log.Infof("Search for query \"%s\" cost %d point(s). %d remaining.", query, totalCost, remaining)
	return prs, nil
}

func (da *DashboardAgent) HeadContexts(ghc githubClient, pr PullRequest) ([]Context, error) {
	org := string(pr.Repository.Owner.Login)
	repo := string(pr.Repository.Name)
	combined, err := ghc.GetCombinedStatus(org, repo, string(pr.HeadRefOID))
	if err != nil {
		return nil, fmt.Errorf("failed to get the combined status: %v", err)
	}
	contexts := make([]Context, 0, len(combined.Statuses))
	for _, status := range combined.Statuses {
		contexts = append(
			contexts,
			Context{
				Context:     status.Context,
				Description: status.Description,
				State:       strings.ToUpper(status.State),
			},
		)
	}
	return contexts, nil
}

func (da *DashboardAgent) GetUser(client *ghclient.Client) (*gogithub.User, error) {
	return client.GetUser("")
}

func (da *DashboardAgent) ConstructSearchQuery(login string) string {
	tokens := []string{"is:pr", "state:open", "author:" + login}
	for i := range da.repos {
		tokens = append(tokens, fmt.Sprintf("repo:\"%s\"", da.repos[i]))
	}
	return strings.Join(tokens, " ")
}

func queryConstrainsRepos(q string) bool {
	tkns := strings.Split(q, " ")
	for _, tkn := range tkns {
		if strings.HasPrefix(tkn, "org:") || strings.HasPrefix(tkn, "repo:") {
			return true
		}
	}
	return false
}