// Copyright 2023 The Gitea Authors. All rights reserved. // SPDX-License-Identifier: MIT //nolint:forbidigo package main import ( "context" "fmt" "log" "net/http" "os" "os/exec" "os/signal" "path" "strconv" "strings" "syscall" "github.com/google/go-github/v53/github" "github.com/urfave/cli/v2" "gopkg.in/yaml.v3" ) const defaultVersion = "v1.18" // to backport to func main() { app := cli.NewApp() app.Name = "backport" app.Usage = "Backport provided PR-number on to the current or previous released version" app.Description = `Backport will look-up the PR in Gitea's git log and attempt to cherry-pick it on the current version` app.ArgsUsage = "<PR-to-backport>" app.Flags = []cli.Flag{ &cli.StringFlag{ Name: "version", Usage: "Version branch to backport on to", }, &cli.StringFlag{ Name: "upstream", Value: "origin", Usage: "Upstream remote for the Gitea upstream", }, &cli.StringFlag{ Name: "release-branch", Value: "", Usage: "Release branch to backport on. Will default to release/<version>", }, &cli.StringFlag{ Name: "cherry-pick", Usage: "SHA to cherry-pick as backport", }, &cli.StringFlag{ Name: "backport-branch", Usage: "Backport branch to backport on to (default: backport-<pr>-<version>", }, &cli.StringFlag{ Name: "remote", Value: "", Usage: "Remote for your fork of the Gitea upstream", }, &cli.StringFlag{ Name: "fork-user", Value: "", Usage: "Forked user name on Github", }, &cli.BoolFlag{ Name: "no-fetch", Usage: "Set this flag to prevent fetch of remote branches", }, &cli.BoolFlag{ Name: "no-amend-message", Usage: "Set this flag to prevent automatic amendment of the commit message", }, &cli.BoolFlag{ Name: "no-push", Usage: "Set this flag to prevent pushing the backport up to your fork", }, &cli.BoolFlag{ Name: "no-xdg-open", Usage: "Set this flag to not use xdg-open to open the PR URL", }, &cli.BoolFlag{ Name: "continue", Usage: "Set this flag to continue from a git cherry-pick that has broken", }, } cli.AppHelpTemplate = `NAME: {{.Name}} - {{.Usage}} USAGE: {{.HelpName}} {{if .VisibleFlags}}[options]{{end}} {{if .ArgsUsage}}{{.ArgsUsage}}{{else}}[arguments...]{{end}} {{if len .Authors}} AUTHOR: {{range .Authors}}{{ . }}{{end}} {{end}}{{if .Commands}} OPTIONS: {{range .VisibleFlags}}{{.}} {{end}}{{end}} ` app.Action = runBackport if err := app.Run(os.Args); err != nil { fmt.Fprintf(os.Stderr, "Unable to backport: %v\n", err) } } func runBackport(c *cli.Context) error { ctx, cancel := installSignals() defer cancel() continuing := c.Bool("continue") var pr string version := c.String("version") if version == "" && continuing { // determine version from current branch name var err error pr, version, err = readCurrentBranch(ctx) if err != nil { return err } } if version == "" { version = readVersion() } if version == "" { version = defaultVersion } upstream := c.String("upstream") if upstream == "" { upstream = "origin" } forkUser := c.String("fork-user") remote := c.String("remote") if remote == "" && !c.Bool("--no-push") { var err error remote, forkUser, err = determineRemote(ctx, forkUser) if err != nil { return err } } upstreamReleaseBranch := c.String("release-branch") if upstreamReleaseBranch == "" { upstreamReleaseBranch = path.Join("release", version) } localReleaseBranch := path.Join(upstream, upstreamReleaseBranch) args := c.Args().Slice() if len(args) == 0 && pr == "" { return fmt.Errorf("no PR number provided\nProvide a PR number to backport") } else if len(args) != 1 && pr == "" { return fmt.Errorf("multiple PRs provided %v\nOnly a single PR can be backported at a time", args) } if pr == "" { pr = args[0] } backportBranch := c.String("backport-branch") if backportBranch == "" { backportBranch = "backport-" + pr + "-" + version } fmt.Printf("* Backporting %s to %s as %s\n", pr, localReleaseBranch, backportBranch) sha := c.String("cherry-pick") if sha == "" { var err error sha, err = determineSHAforPR(ctx, pr) if err != nil { return err } } if sha == "" { return fmt.Errorf("unable to determine sha for cherry-pick of %s", pr) } if !c.Bool("no-fetch") { if err := fetchRemoteAndMain(ctx, upstream, upstreamReleaseBranch); err != nil { return err } } if !continuing { if err := checkoutBackportBranch(ctx, backportBranch, localReleaseBranch); err != nil { return err } } if err := cherrypick(ctx, sha); err != nil { return err } if !c.Bool("no-amend-message") { if err := amendCommit(ctx, pr); err != nil { return err } } if !c.Bool("no-push") { url := "https://github.com/go-gitea/gitea/compare/" + upstreamReleaseBranch + "..." + forkUser + ":" + backportBranch if err := gitPushUp(ctx, remote, backportBranch); err != nil { return err } if !c.Bool("no-xdg-open") { if err := xdgOpen(ctx, url); err != nil { return err } } else { fmt.Printf("* Navigate to %s to open PR\n", url) } } return nil } func xdgOpen(ctx context.Context, url string) error { fmt.Printf("* `xdg-open %s`\n", url) out, err := exec.CommandContext(ctx, "xdg-open", url).Output() if err != nil { fmt.Fprintf(os.Stderr, "%s", string(out)) return fmt.Errorf("unable to xdg-open to %s: %w", url, err) } return nil } func gitPushUp(ctx context.Context, remote, backportBranch string) error { fmt.Printf("* `git push -u %s %s`\n", remote, backportBranch) out, err := exec.CommandContext(ctx, "git", "push", "-u", remote, backportBranch).Output() if err != nil { fmt.Fprintf(os.Stderr, "%s", string(out)) return fmt.Errorf("unable to push up to %s: %w", remote, err) } return nil } func amendCommit(ctx context.Context, pr string) error { fmt.Printf("* Amending commit to prepend `Backport #%s` to body\n", pr) out, err := exec.CommandContext(ctx, "git", "log", "-1", "--pretty=format:%B").Output() if err != nil { fmt.Fprintf(os.Stderr, "%s", string(out)) return fmt.Errorf("unable to get last log message: %w", err) } parts := strings.SplitN(string(out), "\n", 2) if len(parts) != 2 { return fmt.Errorf("unable to interpret log message:\n%s", string(out)) } subject, body := parts[0], parts[1] if !strings.HasSuffix(subject, " (#"+pr+")") { subject = subject + " (#" + pr + ")" } out, err = exec.CommandContext(ctx, "git", "commit", "--amend", "-m", subject+"\n\nBackport #"+pr+"\n"+body).Output() if err != nil { fmt.Fprintf(os.Stderr, "%s", string(out)) return fmt.Errorf("unable to amend last log message: %w", err) } return nil } func cherrypick(ctx context.Context, sha string) error { // Check if a CHERRY_PICK_HEAD exists if _, err := os.Stat(".git/CHERRY_PICK_HEAD"); err == nil { // Assume that we are in the middle of cherry-pick - continue it fmt.Println("* Attempting git cherry-pick --continue") out, err := exec.CommandContext(ctx, "git", "cherry-pick", "--continue").Output() if err != nil { fmt.Fprintf(os.Stderr, "git cherry-pick --continue failed:\n%s\n", string(out)) return fmt.Errorf("unable to continue cherry-pick: %w", err) } return nil } fmt.Printf("* Attempting git cherry-pick %s\n", sha) out, err := exec.CommandContext(ctx, "git", "cherry-pick", sha).Output() if err != nil { fmt.Fprintf(os.Stderr, "git cherry-pick %s failed:\n%s\n", sha, string(out)) return fmt.Errorf("git cherry-pick %s failed: %w", sha, err) } return nil } func checkoutBackportBranch(ctx context.Context, backportBranch, releaseBranch string) error { out, err := exec.CommandContext(ctx, "git", "branch", "--show-current").Output() if err != nil { return fmt.Errorf("unable to check current branch %w", err) } currentBranch := strings.TrimSpace(string(out)) fmt.Printf("* Current branch is %s\n", currentBranch) if currentBranch == backportBranch { fmt.Printf("* Current branch is %s - not checking out\n", currentBranch) return nil } if _, err := exec.CommandContext(ctx, "git", "rev-list", "-1", backportBranch).Output(); err == nil { fmt.Printf("* Branch %s already exists. Checking it out...\n", backportBranch) return exec.CommandContext(ctx, "git", "checkout", "-f", backportBranch).Run() } fmt.Printf("* `git checkout -b %s %s`\n", backportBranch, releaseBranch) return exec.CommandContext(ctx, "git", "checkout", "-b", backportBranch, releaseBranch).Run() } func fetchRemoteAndMain(ctx context.Context, remote, releaseBranch string) error { fmt.Printf("* `git fetch %s main`\n", remote) out, err := exec.CommandContext(ctx, "git", "fetch", remote, "main").Output() if err != nil { fmt.Println(string(out)) return fmt.Errorf("unable to fetch %s from %s: %w", "main", remote, err) } fmt.Println(string(out)) fmt.Printf("* `git fetch %s %s`\n", remote, releaseBranch) out, err = exec.CommandContext(ctx, "git", "fetch", remote, releaseBranch).Output() if err != nil { fmt.Println(string(out)) return fmt.Errorf("unable to fetch %s from %s: %w", releaseBranch, remote, err) } fmt.Println(string(out)) return nil } func determineRemote(ctx context.Context, forkUser string) (string, string, error) { out, err := exec.CommandContext(ctx, "git", "remote", "-v").Output() if err != nil { fmt.Fprintf(os.Stderr, "Unable to list git remotes:\n%s\n", string(out)) return "", "", fmt.Errorf("unable to determine forked remote: %w", err) } lines := strings.Split(string(out), "\n") for _, line := range lines { fields := strings.Split(line, "\t") name, remote := fields[0], fields[1] // only look at pushers if !strings.HasSuffix(remote, " (push)") { continue } // only look at github.com pushes if !strings.Contains(remote, "github.com") { continue } // ignore go-gitea/gitea if strings.Contains(remote, "go-gitea/gitea") { continue } if !strings.Contains(remote, forkUser) { continue } if strings.HasPrefix(remote, "git@github.com:") { forkUser = strings.TrimPrefix(remote, "git@github.com:") } else if strings.HasPrefix(remote, "https://github.com/") { forkUser = strings.TrimPrefix(remote, "https://github.com/") } else if strings.HasPrefix(remote, "https://www.github.com/") { forkUser = strings.TrimPrefix(remote, "https://www.github.com/") } else if forkUser == "" { return "", "", fmt.Errorf("unable to extract forkUser from remote %s: %s", name, remote) } idx := strings.Index(forkUser, "/") if idx >= 0 { forkUser = forkUser[:idx] } return name, forkUser, nil } return "", "", fmt.Errorf("unable to find appropriate remote in:\n%s", string(out)) } func readCurrentBranch(ctx context.Context) (pr, version string, err error) { out, err := exec.CommandContext(ctx, "git", "branch", "--show-current").Output() if err != nil { fmt.Fprintf(os.Stderr, "Unable to read current git branch:\n%s\n", string(out)) return "", "", fmt.Errorf("unable to read current git branch: %w", err) } parts := strings.Split(strings.TrimSpace(string(out)), "-") if len(parts) != 3 || parts[0] != "backport" { fmt.Fprintf(os.Stderr, "Unable to continue from git branch:\n%s\n", string(out)) return "", "", fmt.Errorf("unable to continue from git branch:\n%s", string(out)) } return parts[1], parts[2], nil } func readVersion() string { bs, err := os.ReadFile("docs/config.yaml") if err != nil { if err == os.ErrNotExist { log.Println("`docs/config.yaml` not present") return "" } fmt.Fprintf(os.Stderr, "Unable to read `docs/config.yaml`: %v\n", err) return "" } type params struct { Version string } type docConfig struct { Params params } dc := &docConfig{} if err := yaml.Unmarshal(bs, dc); err != nil { fmt.Fprintf(os.Stderr, "Unable to read `docs/config.yaml`: %v\n", err) return "" } if dc.Params.Version == "" { fmt.Fprintf(os.Stderr, "No version in `docs/config.yaml`") return "" } version := dc.Params.Version if version[0] != 'v' { version = "v" + version } split := strings.SplitN(version, ".", 3) return strings.Join(split[:2], ".") } func determineSHAforPR(ctx context.Context, prStr string) (string, error) { prNum, err := strconv.Atoi(prStr) if err != nil { return "", err } client := github.NewClient(http.DefaultClient) pr, _, err := client.PullRequests.Get(ctx, "go-gitea", "gitea", prNum) if err != nil { return "", err } if pr.Merged == nil || !*pr.Merged { return "", fmt.Errorf("PR #%d is not yet merged - cannot determine sha to backport", prNum) } if pr.MergeCommitSHA != nil { return *pr.MergeCommitSHA, nil } return "", nil } func installSignals() (context.Context, context.CancelFunc) { ctx, cancel := context.WithCancel(context.Background()) go func() { // install notify signalChannel := make(chan os.Signal, 1) signal.Notify( signalChannel, syscall.SIGINT, syscall.SIGTERM, ) select { case <-signalChannel: case <-ctx.Done(): } cancel() signal.Reset() }() return ctx, cancel }