1//go:build ignore
 2
 3// Command tools/vendor/pack.go  creates `vendor.tar.gz` from the current
 4// project `vendor` directory.  Intended for use as a build support tool.
 5package main
 6
 7import (
 8	"archive/tar"
 9	"compress/gzip"
10	"fmt"
11	"io"
12	"io/fs"
13	"log/slog"
14	"os"
15	"path/filepath"
16	"runtime"
17)
18
19// vendor.tar.gz pack
20func main() {
21	const (
22		archiveName   = "vendor.tar.gz"
23		vendorDir     = "vendor"
24		vendorDirMode = 0o755
25	)
26
27	// discover this file's location
28	_, callerFilepath, _, callerFound := runtime.Caller(0)
29	if !callerFound {
30		slog.Error("failed to find caller location")
31		return
32	}
33	archivePath := filepath.Join(filepath.Dir(callerFilepath), archiveName)
34
35	archiveFile, err := os.Create(archivePath)
36	if err != nil {
37		slog.Error("failed to create output tarball",
38			slog.String("err", err.Error()),
39			slog.String("path", archivePath))
40		return
41	}
42	defer func() { _ = archiveFile.Close() }()
43
44	gzw := gzip.NewWriter(archiveFile)
45	defer func() { _ = gzw.Close() }()
46
47	tw := tar.NewWriter(gzw)
48	defer func() { _ = tw.Close() }()
49
50	err = filepath.WalkDir(
51		vendorDir,
52		func(path string, d fs.DirEntry, err error) error {
53			if err != nil {
54				return fmt.Errorf("failed to walk vendor dir path=%q: %w", path, err)
55			}
56			relPath, err := filepath.Rel(vendorDir, path)
57			if err != nil {
58				return fmt.Errorf("failed to create relative path path=%q: %w", path, err)
59			}
60			if relPath == "." {
61				return nil
62			}
63			info, err := d.Info()
64			if err != nil {
65				return fmt.Errorf("failed to get file info path=%q: %w", path, err)
66			}
67			if info.Mode()&os.ModeSymlink != 0 {
68				return nil
69			}
70			header, err := tar.FileInfoHeader(info, "")
71			if err != nil {
72				return fmt.Errorf("failed to create tar header path=%q: %w", path, err)
73			}
74			header.Name = relPath
75			err = tw.WriteHeader(header)
76			if err != nil {
77				return fmt.Errorf("failed to write tar header path=%q: %w", path, err)
78			}
79			if info.IsDir() {
80				return nil
81			}
82			vendorFile, err := os.Open(path)
83			if err != nil {
84				return fmt.Errorf("failed to open vendor file path=%q: %w", path, err)
85			}
86			_, err = io.Copy(tw, vendorFile)
87			if err != nil {
88				return fmt.Errorf("failed to write vendor file to tar path=%q: %w", path, err)
89			}
90			return nil
91		})
92	if err != nil {
93		slog.Error("failed to package vendor directory",
94			slog.String("err", err.Error()))
95	}
96}