diff options
Diffstat (limited to 'contrib/backport/backport.go')
| -rw-r--r-- | contrib/backport/backport.go | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/contrib/backport/backport.go b/contrib/backport/backport.go new file mode 100644 index 0000000..dd6b412 --- /dev/null +++ b/contrib/backport/backport.go @@ -0,0 +1,474 @@ +// 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/v64/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 +} |