mugit/internal/git/gitservice/gitservice.go (view raw)
| 1 | package gitservice |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "fmt" |
| 6 | "io" |
| 7 | "os/exec" |
| 8 | "sync" |
| 9 | "syscall" |
| 10 | ) |
| 11 | |
| 12 | // InfoRefs executes git-upload-pack --advertise-refs for smart-HTTP discovery. |
| 13 | func InfoRefs(dir string, out io.Writer) error { |
| 14 | cmd := exec.Command("git", |
| 15 | "upload-pack", |
| 16 | "--stateless-rpc", |
| 17 | "--advertise-refs", |
| 18 | ".") |
| 19 | cmd.Dir = dir |
| 20 | cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true} |
| 21 | |
| 22 | stdout, err := cmd.StdoutPipe() |
| 23 | if err != nil { |
| 24 | return fmt.Errorf("stdout pipe: %w", err) |
| 25 | } |
| 26 | cmd.Stderr = cmd.Stdout |
| 27 | |
| 28 | if err := cmd.Start(); err != nil { |
| 29 | return fmt.Errorf("start git-upload-pack: %w", err) |
| 30 | } |
| 31 | |
| 32 | if err := PackLine(out, "# service=git-upload-pack\n"); err != nil { |
| 33 | return fmt.Errorf("write pack line: %w", err) |
| 34 | } |
| 35 | if err := PackFlush(out); err != nil { |
| 36 | return fmt.Errorf("flush pack: %w", err) |
| 37 | } |
| 38 | |
| 39 | var buf bytes.Buffer |
| 40 | if _, err := io.Copy(&buf, stdout); err != nil { |
| 41 | return fmt.Errorf("copy stdout to buffer: %w", err) |
| 42 | } |
| 43 | |
| 44 | if err := cmd.Wait(); err != nil { |
| 45 | return fmt.Errorf("git-upload-pack: %w", err) |
| 46 | } |
| 47 | |
| 48 | if _, err := io.Copy(out, &buf); err != nil { |
| 49 | return fmt.Errorf("copy buffer to output: %w", err) |
| 50 | } |
| 51 | |
| 52 | return nil |
| 53 | } |
| 54 | |
| 55 | // UploadPack executes git-upload-pack for smart-HTTP git fetch/clone. |
| 56 | // StatelessRPC should be true in case it's used over http, and false for ssh. |
| 57 | func UploadPack(dir string, statelessRPC bool, in io.Reader, out io.Writer) error { |
| 58 | return gitCmd("upload-pack", config{ |
| 59 | Dir: dir, |
| 60 | StatelessRPC: statelessRPC, |
| 61 | AllowFilter: true, |
| 62 | Stdin: in, |
| 63 | Stdout: out, |
| 64 | }) |
| 65 | } |
| 66 | |
| 67 | func ReceivePack(dir string, in io.Reader, out, errout io.Writer) error { |
| 68 | return gitCmd("receive-pack", config{ |
| 69 | Dir: dir, |
| 70 | Stdin: in, |
| 71 | Stdout: out, |
| 72 | Stderr: errout, |
| 73 | }) |
| 74 | } |
| 75 | |
| 76 | type config struct { |
| 77 | Dir string |
| 78 | StatelessRPC bool |
| 79 | AllowFilter bool |
| 80 | ExtraArgs []string |
| 81 | Stdin io.Reader |
| 82 | Stdout io.Writer |
| 83 | Stderr io.Writer |
| 84 | } |
| 85 | |
| 86 | func gitCmd(service string, c config) error { |
| 87 | args := []string{} |
| 88 | if c.AllowFilter { |
| 89 | args = append(args, "-c", "uploadpack.allowFilter=true") |
| 90 | } |
| 91 | |
| 92 | args = append(args, service) |
| 93 | if c.StatelessRPC { |
| 94 | args = append(args, "--stateless-rpc") |
| 95 | } |
| 96 | |
| 97 | args = append(args, c.ExtraArgs...) |
| 98 | args = append(args, ".") |
| 99 | |
| 100 | cmd := exec.Command("git", args...) |
| 101 | cmd.Dir = c.Dir |
| 102 | cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true} |
| 103 | |
| 104 | var ( |
| 105 | err error |
| 106 | stdin io.WriteCloser |
| 107 | ) |
| 108 | |
| 109 | if c.Stdin != nil { |
| 110 | stdin, err = cmd.StdinPipe() |
| 111 | if err != nil { |
| 112 | return err |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | stdout, err := cmd.StdoutPipe() |
| 117 | if err != nil { |
| 118 | return err |
| 119 | } |
| 120 | if c.Stderr != nil { |
| 121 | cmd.Stderr = c.Stderr |
| 122 | } else { |
| 123 | cmd.Stderr = cmd.Stdout |
| 124 | } |
| 125 | |
| 126 | if err := cmd.Start(); err != nil { |
| 127 | return fmt.Errorf("start %s: %w", service, err) |
| 128 | } |
| 129 | |
| 130 | if c.Stdin != nil { |
| 131 | // Don't add to WaitGroup - stdin closes when client closes, |
| 132 | // shouldn't block waiting for output to finish |
| 133 | go func() { |
| 134 | defer stdin.Close() |
| 135 | io.Copy(stdin, c.Stdin) |
| 136 | }() |
| 137 | } |
| 138 | |
| 139 | var wg sync.WaitGroup |
| 140 | var stdoutErr error |
| 141 | |
| 142 | wg.Go(func() { |
| 143 | _, stdoutErr = io.Copy(c.Stdout, stdout) |
| 144 | }) |
| 145 | |
| 146 | wg.Wait() |
| 147 | |
| 148 | if stdoutErr != nil { |
| 149 | return fmt.Errorf("copy stdout: %w", stdoutErr) |
| 150 | } |
| 151 | |
| 152 | if err := cmd.Wait(); err != nil { |
| 153 | return fmt.Errorf("%s: %w", service, err) |
| 154 | } |
| 155 | return nil |
| 156 | } |
| 157 | |
| 158 | // PackLine writes a pkt-line formatted string. |
| 159 | func PackLine(w io.Writer, s string) error { |
| 160 | _, err := fmt.Fprintf(w, "%04x%s", len(s)+4, s) |
| 161 | return err |
| 162 | } |
| 163 | |
| 164 | // PackFlush writes a flush packet. |
| 165 | func PackFlush(w io.Writer) error { |
| 166 | _, err := fmt.Fprint(w, "0000") |
| 167 | return err |
| 168 | } |
| 169 | |
| 170 | // PackSideband writes a message to sideband channel (displays as "remote: <msg>" in git client). |
| 171 | // Channel 2 = progress/info, Channel 3 = error. |
| 172 | func PackSideband(w io.Writer, channel byte, msg string) error { |
| 173 | return PackLine(w, string(channel)+msg) |
| 174 | } |
| 175 | |
| 176 | // PackError writes an ERR packet for protocol-level errors. |
| 177 | // Git displays this as: fatal: remote error: <msg> |
| 178 | func PackError(w io.Writer, msg string) error { |
| 179 | return PackLine(w, "ERR "+msg) |
| 180 | } |